Saturday, August 1, 2020

The six weeks' want: backyard garden reality

Two posts back, after a friend imagined Mike and me living indefinitely off our backyard garden during the COVID-19 lockdown, I promised to dig more deeply into why that idea is mistaken. Basically it comes down to three interrelated issues: seasonality, space, and opportunity costs. In this post I will examine how these three factors affect the possibilities and reflect the limitations of backyard gardens.

Before I begin, please do not get the idea that I am dismissing backyard gardens! If I did not recognize the continuing value of my own garden to Mike and me, I would not be gardening. At the same time, thinking that all you need to have is a few packages of seed, a shovel, and a gardening book and you will grow more than you can eat whenever you think you will need to is misguided at best and dangerous at worst.

Let’s start with seasonality, because the timing of the COVID-19 pandemic brought that to the forefront of my mind when I read my friend’s comment. In St. Louis County, MO, where Mike and I live, restrictions to the size of gatherings began to be applied in early March, with the fullest extent of the lockdown going into effect on March 23. The first stage of re-opening began on May 18.

At the time the first COVID-19 restrictions began, Mike and I had no vegetables or fruits from the garden left to eat, except for some garlic. Everything else had already been eaten, with about a month to go before I could plant anything in the garden, and about two months before the first significant harvest, of strawberries, would begin. It is only since mid-July that we are eating garden vegetables at every meal, with enough extra to make some pickles and tomato sauce for later (though we did have a few weeks of salads and some bok choy and cabbage for stir-fries in June). For about three weeks or so from mid-May through early June we ate strawberries every day and made 2 gallons of strawberry wine and about a quart or so of strawberry cordial from what we couldn’t eat, but except for a handful of apricots and a couple of pounds of peaches we haven’t had any meaningful amount of fruit from the garden since early June. That will change in August, but please pay close attention to these long time lags during which we had no fresh fruits or vegetables from the garden. Notice that we are talking not days, not even weeks, but months.

This is the problem of seasonality. In a climate with a long, cold winter there will be months that go by when an open garden has nothing to harvest in it. If a gardener can store some of their harvest then the time when food starts running low is delayed somewhat, but there is a reason that the phrase “six weeks’ want” is associated with the transition to early spring, as this was traditionally about the time when the stored vegetables and fruits ran out or spoiled in the warming weather. Because of the time lag in the growing season between planting seeds or seedlings and harvesting, and because harvest ends months before it can begin again, gardeners in cold-winter climates will be eating mostly fruits and vegetables that farmers grew for at least several weeks before their own gardens begin producing again. This is the inevitable result of the compromises I and all gardeners must make between seasonality, garden size, and opportunity costs.

Suppose you live in a cold-winter climate and are determined to minimize the issue of seasonality. You could grow more food so you can store some of it, for instance. How could you grow more food to store? You could increase the size of the garden, but only if you have the space to do so, and only if you have time, not just to tend to the increased garden size, but also time to put up some of the foods that you grew (the opportunity costs I mentioned, because you’ll have to not do something else in order to garden or to put up pickles or tomato sauce). Or you might decide to freeze some of the crop, but you’ll need to find the time to prepare and freeze it, and if you don’t already have enough freezer space, you’ll need to get a freezer. That’s another kind of opportunity cost, because you can’t spend the money on something else if you spend it on a freezer, plus you’ll need to pay the cost of the electricity to run the freezer (and what happens if the electricity shuts off?). Or you could store some fresh produce in a root cellar or a smaller-scale version of a root cellar such as a buried cooler, but again you’ll have to increase the size of the garden to grow the extra produce, and you’ll have to improvise a storage system like our anteroom, or use space in a cool closet, a basement, or your living areas (Carol Deppe stores squashes in her living areas, and I store them under a table in our living room), or perhaps fashion your own root cellar. Even then, when the ground begins to warm in early spring, in March here, I have found that anything I still have stored deteriorates rapidly. Or you could cover part or all of your outdoor garden so you can harvest something in the winter, but again space and opportunity costs will limit what you can do in a backyard situation. My experience with cold frames and the front porch suggests that to get a substantial amount of food you will need a lot of covered space, and you’ll have more pest problems in a covered space than you will in an open garden. So these three interrelated factors will determine how much of your vegetable and fruit harvest you can store, and it is almost certainly going to be a lot less than you think if you have a standard-sized urban or suburban backyard garden, nowhere near enough to get you into the following summer.

You can partially mitigate the six weeks’ want by adding grain and dry bean crops to your garden. Even though Mike and I were out of fresh garden food (except for garlic) by March, we had over 45 pounds of stored flour corn and at least 10 pounds of stored popcorn to eat, representing harvests from the previous few years. I also grow blackeyed peas as a dry bean crop most years, although I didn’t grow any in 2019. One of the best ways to use these crops, since they can be stored for a few to several years, is to hold them in reserve until the winter squash and root crops, like potatoes and turnips, have been eaten. Then start eating the grains and beans, supplementing them with whatever you may have frozen, canned, or dried, plus the earliest leafy greens from the garden (sorrel, spinach, asparagus) or foraged from the yard or elsewhere (dandelions), until you begin to get enough of the salad and cabbage-family greens to eat a real salad. Still, to do this you’ll need to devote a significant amount of garden space to grains and to the dry beans, because they do not yield as heavily as most vegetables or fruits on a square-foot basis. Besides that, you’ll also need to grow enough grain plants for sufficient genetic diversity for seed-saving if you plan to do that, and enough of both for replanting as well as eating. Plus there is an opportunity cost not just for growing the plants but also for the time you’ll spend in processing them to a state in which you can cook them and in the equipment required to grind the grain.

In the next post I will describe how I have balanced these three factors – seasonality, space, and opportunity cost – in my own garden, and how that balance has changed over the years. By giving you a real-world example I hope to make the general principles I’ve discussed here easier to apply in your own gardening efforts. Till then, I wish you well.

Sunday, June 28, 2020

A Garden Tour

I haven’t forgotten about the more detailed discussion on how much food one can reasonably expect to produce from a backyard garden, but it has occurred to me that a good start to that conversation might be to take you on a virtual tour of my backyard garden. Sit back and relax as we travel in time to June 20th and in space to near the confluence of the Missouri and Mississippi Rivers, where you can meet my garden.

Let’s begin here at the southeastern corner, a good place to get an overview of the garden as a whole.

The three corn beds are the closest to this corner. You may notice that there are paths between every two rows. The paths are about 1 foot wide. The beds are about 4 feet wide, with two evenly spaced rows of corn in each bed. Each bed is 25 feet long.

The windmill-looking object toward the back? That is supposed to make a vibration when the windmill turns, which is transmitted down the copper rod on which the windmill sits and into the ground. Supposedly the underground noise makes it an unpleasant place for moles to live. While I haven’t noticed any mole hills in the garden since I put it up, it hasn’t made life uncomfortable enough to free the garden of other burrowing mammals. Too bad; I would have had more potato onions if the windmill worked on all burrowing mammals.

There are three more beds of the same size behind the corn beds and another six beds to the left of the corn beds for a total of twelve beds, all sized and spaced the same way. Around the outside of all the beds, between the beds and the fence, is a 4 to 5 foot wide path for easy walking and mowing and for bringing cartloads of materials to and from the beds. There is a six foot wide path up the middle, between the two groups of six beds, also for walking and transporting materials. Thus the fenced-in area is about 65 feet by about 40 feet (about 2600 square feet) while the total growing area of the beds is 1200 square feet. If we didn’t have wild rabbits in the yard I would not need the fence, but since we do have rabbits and they will eat most of the plants that I grow, the fence keeps out enough of the rabbits enough of the time to allow us to eat most of the food grown within the fenced area. That also means that the fenced area of the yard cannot be used for any purpose other than gardening. The garden is far enough away from trees to receive nearly full sun, allowing for excellent growth of vegetables and small fruits.

The photo above shows the three corn beds looking towards the neighboring yard to the east, plus an empty bed just north of the corn beds. Each bed has about 75 corn plants in it, in groups of 2 to 3 plants about two feet apart within a row. There are also some pumpkin plants growing in the middle of each bed. These shade the soil to some extent and seem to keep corn-eating critters frustrated. If they make a few pumpkins that is a bonus, but they are present mostly to protect the corn. I have tried growing beans up the corn stalks, but the bean plants grow too tall for me to reach the beans.

A few days prior to taking the picture, the empty bed north of the corn beds contained potato onion and garlic plants along with plenty of weeds. The potato onions and some of the garlic plants are shown below.

They have been laid on screens on the front porch so they can dry for a few weeks. The weeds are composting in one of the compost bins, mixed with some of last autumn’s leaves.

Since the photos were taken I have planted seeds of cucumbers, zucchini, and edamame (a kind of soybean eaten like green peas) into the empty bed for a late summer and early autumn harvest, as well as sunflowers and zinnias for their beauty. This is the last planting of seeds that I will do before late July or early August, when I plant the salad crops for autumn harvests.

These are the two beds north of the empty bed, on the same side as the corn. The bed to the right includes peppers, tomatoes, and eggplants, with nasturtiums in between. (Ever eaten a nasturtium blossom? They add beauty and a mild radish-like flavor to salads.) Years of experience has taught me that overcrowding the peppers, tomatoes, and eggplants reduces the per-plant harvest. I used to plant basil between them, but basil gets too tall and wide, overpowering the shorter peppers and eggplants. Nasturtiums, which grow out but not tall, seem to work the best to cover most of the soil between the larger plants while not stealing sun or nutrients from them.

The bed to the left includes cucumbers, butternut squash, zucchini, and melons. The squash and zucchini plants in the middle look small and far apart, but they are beginning a rapid growth spurt and will have the bed almost covered in another month of so. Meanwhile, training the cucumbers and melons up the A frame trellises makes it easier to find the fruits before they go over-ripe and keeps them safe from small ground-dwelling mammals. Two plants will fully cover each trellis within another month or six weeks.

This photo shows the bed with herbs and flowers in it, in the group of six beds left (west) of the beds already shown. The herbs include culinary herbs like cilantro (which is now flowering, the white flowers in the middle of the photo), parsley, dill, spearmint, and basil. It also includes traditional medicinal herbs like calendula (yellow flowers next to the blue flowers at the right end of the bed), yarrow (white flowers at the left end of the bed) and purple coneflower, which is not yet in bloom. It also includes another spring flowering native plant, coreopsis (yellow flowers farthest to the left) and the blue-purple flowers of batchelors buttons toward the right end of the bed. Finally, a perennial salad plant, sorrel, can be seen between the blue flowers and the edge of the bed. This bed offers some ecological benefits to the garden as a whole as well as some herbs and food for us.

In the middle of this photo, to the north of the herb bed, is the strawberry bed. After they finished production I mowed the plants. Mowing the plants forces the plants to put their resources into re-growing their crowns rather than into sending out runners to make more plants. Any more plants would overcrowd the bed, reducing the yield of strawberries. Then I’d have to remove the old plants and re-plant the bed with new plants from runners. I’ve done this before, when I moved the strawberry bed to this location … it’s a lot of work, something I don’t care to do often. An article by Helen and Scott Nearing from an old issue of Organic Gardening magazine discusses their experience with mowing strawberries following the end of production. Their original plants produced for 10 years under this treatment!


To the left of the strawberries are the raspberries. A few years ago I decided to grow them up through tomato cages in an attempt to keep the canes from drooping over plants in the beds to either side of them. It makes the raspberries much easier to harvest, but the plants don’t seem to be growing as thickly this year. Perhaps the soil has been depleted where the roots are, since the plants aren’t allowed to spread out beyond the crown. Adding more minerals to their bed next year may help.

In this photo you can see the bed of potato plants on the other side of the raspberry bed. I pushed soil from the edges of the bed up against the tops of the plants a couple of times as they were growing, which gardeners call hilling up. Because potato plants don’t make any potatoes underneath the pieces of potato that they grew from (the seed tubers), but they will make potatoes from roots that grow from buried stems, hilling up is an easy way to increase the yield of a potato bed. These plants have about another month to grow before they die and the potatoes are ready to harvest.

This bed on the other side of the potato bed holds spring and early summer salad crops and also carrots, beets, and leeks. All of these plants are planted in rows parallel to the short dimension of the bed. In front are four cabbage plants, with a cabbage harvested from one of them; behind the cabbages are the beets, leeks, and carrots. Behind the carrots, but shorter than them so out of sight, are lettuces and endives.

The remaining bed, shown above, holds plants in the bean and pea family. At the near end of the bed is a bean tower with a pole variety of green beans growing up the strings. Another tower at the far end has a pole variety of lima beans. Between them, I have set up pea fences to keep a bush cowpea variety within bounds. Blackeyed peas, like the variety I am growing, are a type of cowpea, but there are many other shapes and colors of cowpeas available for gardeners with a long enough season. The cowpea, lima bean, and green bean are all in different genuses so they won’t cross-pollinate, which allows me to save seeds.


Now that you have a better idea of the size of my garden and how it is laid out, we can go on to a discussion of backyard gardens, including how much garden you can grow in the time and space you have available, how much food you might reasonably expect to grow from your garden, seasonal harvesting and eating, and so forth. I expect that discussion to begin next month. Till then, may your own garden be successful!

Thursday, April 30, 2020

Gardening in the spring of COVID-19

This redbud was in full bloom a week ago

Awhile back I made my first social media post in several years, to the effect that Mike and I were doing fine in the midst of the COVID-19 pandemic. A friend of mine responded that he was imagining Mike and I living off our garden indefinitely. To be sure, our vegetable and small fruit garden is larger than most backyard gardens, but like most people, including me before I started gardening, my friend isn’t fully aware of how much he eats in a year and how much land it takes to produce that amount of food. In a later post I plan to dig more deeply into this topic, based on the 25 plus years of experience I have in growing backyard gardens. In the meantime, I’d like to take a look at the upsurge in gardening that the loss of jobs and social distancing measures associated with COVID-19 has engendered and why I think that it illustrates the biggest benefit of growing backyard gardens.

In the US the COVID-19 isolation measures came during March for most of the population, near the beginning of the growing season or not long before it begins for those of us east of the Rockies. Most US garden seed retailers experience their heaviest seed sales during late winter and early spring, after gardeners have received seed catalogs and decided what to grow and how much seed they will need for their gardens. After many people lost their jobs or began to work at home in response to the various measures enacted to reduce the transmission rate of COVID-19, some of them realized that they had the time to begin a garden and to cook and a need to reduce their grocery expenditures. They promptly began ordering seeds and garden supplies, as did the habitual gardeners who usually order seeds at this time of year. The increased business combined with the need to implement social distancing measures in the buildings in which the seed orders are pulled and prepared for shipping has resulted in delays in processing and sending seed orders. A number of seed retailers have been forced to stop accepting new orders for a period of time while they caught up on pulling and mailing orders they had already received. While this makes things more difficult for erstwhile gardeners who must wait for their seed orders to arrive, I am grateful that my favorite seed retailers will be among the businesses that do well despite the economic disruptions caused by the isolation measures.

Recently some US meat processing plants have been forced to close because of the rapid spread of COVID-19 among the workers in the plants. As a result there has been some discussion of COVID-19 effects on future food supplies in the media. This ties in with the increase in gardening in an interesting way, which I will highlight in this post.

John Jeavons, in his How to Grow More Vegetables book, states that many people grow backyard gardens for what he calls nutrition intervention. In other words, they grow in their gardens mostly vegetables eaten fresh or minimally cooked. However, he feels that more people should focus their backyard gardening efforts on sources of calories (grains, dry beans, and potatoes primarily). If there were a shortage of grains, dry beans, or potatoes in the US his position would have merit. However, to my mind he fails to take into account the effect of automation on the production of these crops, compared to the needs for fruit and vegetable crops to be harvested, and sometimes planted and tended as well, primarily by human labor.

Anyone who lives in the Midwest, as I do, has seen the effect of cheap oil and mechanization on farmland. It is especially noticeable during harvest season, when huge machinery operated by one person drives slowly through the field, ingesting entire corn plants on one end and spitting out clean corn seed on the other. Whatever you may think about eating oil (which is essentially what we are doing in the large-scale agriculture of the US Midwest), social distancing is built into it. These farms don’t need seasonal farmhands to produce a crop. Moreover, the farmers planned their farms and ordered their seeds before COVID-19 caused its havoc. That corn, wheat, rice, and soybean seed, and those seed potatoes and dry bean seed, have been or will be planted. If the livestock that would normally eat Midwestern-grown corn and soybeans is significantly reduced in number due to knock-on effects from COVID-19, humans can eat corn and soybeans too. We may not like it as much as meat (as an omnivore myself, I do not look forward to less meat availability and higher prices), but if that is what there is, we’ll eat it. If you aren’t already eating a substantial amount of these crops, you may want to spend the next few months finding cookbooks on how to make good use of them and starting to experiment with the recipes.

What about vegetables and fruits? While planting and tending of some of these have been automated to a greater or lesser degree, harvest is often still a labor-intensive activity requiring human minds and bodies to accomplish. It is these human minds and bodies that could be in short supply at crucial points in the growing season. I have already read reports that vegetable crops in Florida had to be plowed under because the social isolation measures meant there were not enough workers to harvest the crop, and the institutions that the vegetables were meant for had closed so that even if the crops could be harvested, there were no buyers for them.

At the same time, it is exactly these crops – lettuce and other salad greens and roots; tomatoes and peppers; green beans and sweet corn; zucchini and cucumbers; root vegetables like carrots and onions – that are easiest to grow well in a small backyard garden. Fruits like strawberries and raspberries, if protected from birds and other predators, are also labor intensive, vitamin-rich, and delicious crops that work well in a backyard garden setting. If these were all the crops that I grew, my garden could be about half the size it is now, meaning it would need half the labor that it currently does. And these are exactly the seeds and plants that folks thrown into their backyards are seeking to grow, and exactly the crops that are most likely to be in short supply if social distancing and closed borders reduce the workforce of the large vegetable-growing farms in Florida, California, and other places where this kind of farming is prevalent in the landscape. Thus I take it as a good sign that so many people are taking up backyard vegetable and fruit growing this spring. We need more backyard and small scale vegetable and fruit growing to provide the vitamins and minerals (and the tastes) that are missing in the large-scale grain, dry bean, and potato crops. Combine the calories available from the latter with the nutrition and taste of the former, and that will make for better health and a more resilient food system overall. If my blog helps you to grow a better backyard garden, I will have accomplished one of my goals in writing it.

I hope to have the next post up sometime in May, but May is also the busiest garden month of the year. Sometime in the next couple of months I expect to return to the topic I brought up in the first paragraph. Until then, I wish all of you good health and happiness!

Tuesday, March 24, 2020

More fun in the garden in 2020

Not only was 2019 wetter than normal, but 2020 has been wetter than normal as well. You can see the standing water in low spots in the backyard in this photo, taken on March 18. The soil is saturated, with more rain to come later this week. Fortunately the vegetable garden itself (on the other side of the fence) has enough of a slope that water does not puddle on it.

In my previous post I described how I asked last year’s garden if I can use my urine as a source of nitrogen. With the caveats that I mentioned, the garden seems to have answered in the affirmative. Thus I’ll use urine on all the vegetable and grain beds this year to replace cottonseed meal and assess the effects that it has. But this isn’t the only question I’ll ask the garden to answer in 2020. Read on to learn what else I’m asking the garden, and why.

Nitrogen isn’t the only nutrient that I’ve needed to import in order to re-mineralize the soil in my garden. In this post from 2019, I discussed the results of asking the garden if the wood ashes left over from burning wood in our wood stove can be used to replace, in full or in part, the materials I purchased to supply calcium (Ca), phosphorus (P), and potassium (K). This experiment was done on a single bed, the bed in which I planted garlic and potato onions in autumn 2018. For this bed I added enough wood ashes to correct the entire deficiency in K and about 1/3 of the deficiency in P, which also supplied an excess of Ca and magnesium (Mg). After harvesting the garlic and potato onions in June 2019, I sent in a sample of the soil in this bed for analysis, in order to learn if using that large an amount of wood ashes (about 7 pounds for the 100 square foot bed) had brought that bed out of balance with the rest of the garden. The table below gives the analysis of nutrient deficiencies in the garden when the re-mineralization program was begun (spring 2013); in all the beds except the allium bed in spring 2019; in the allium bed in July 2019, after the allium harvest; and in all the beds except the allium bed and the bed that I ran out of time to plant in 2019 (spring 2020, from a sample I took on March 11).

Let’s look at the results in detail. TCEC means total cation exchange capacity: how well the soil can hold onto cations until the plants growing in it need them. The cations are everything from calcium (Ca) down in the table and are stored on the clay fraction of the soil. Steve Solomon says that a soil with a TCEC of 10 or more can hold onto sufficient cations to supply the plants’ needs for an entire growing season. Less than that means that the gardener should consider adding more of the re-mineralization mix about halfway through the growing season. Although the TCEC of my soil is less than 10, I have not done this, so I may not be obtaining as high yields as I could. I do, however, get decent yields while using less of the sources of the nutrients.

The TCEC of the allium bed may be somewhat higher than that of the rest of the garden in 2019, but as I discussed in this post, there is enough uncertainty about the precision and accuracy of the test to make any firm statement inadvisable. The same uncertainty affects the organic matter percentage. pH measurements have higher precision and accuracy, and the change in pH in the allium bed compared to the rest of the garden is in the direction I expect for adding wood ashes, which raise the pH. Fortunately it did not raise it over 7 even for the high amount of wood ashes I used, since vegetables generally prefer a soil with a pH in the range of 6 to 7. Since we receive rain during the growing season, the acidic rain will help to neutralize the high pH wood ashes. Those of you who live in arid or semi-arid areas or who experience dry growing seasons (anywhere west of about the 100th parallel of longitude in the US) will need to check with your state extension service or local gardening organization to learn if you can safely add wood ashes to your soil and if so, the maximum amount you can add each season. Based on these results, I will feel comfortable in adding as much as five pounds or so of wood ashes to any bed which does not already have an excess of calcium, to correct, in whole or in part, deficiencies of Ca, K, Mg, and/or P.

Now consider the 2020 results compared to the 2013 and 2019 results. There have certainly been changes, but they don’t appear to be consistent. The excesses of P and K that I was so pleased about in 2019 have swung over to deficiencies. What, if anything, can I learn about how the re-mineralization project affects the soil over time?

First, plants take up these nutrients from the soil to form their bodies. When I harvest the plants, I remove and Mike and I eat those nutrients. If there isn’t another source that replenishes the lost nutrients, over time the soil continues to lose them until it no longer can support plant growth.

Nature has many different ways to keep nutrients cycling through the air, water, and soil; if you’re curious, you can find descriptions in ecology textbooks. However, if the cycle for any particular nutrient cannot supply enough of it to replace what I remove via the harvest, then that nutrient will, over time, become deficient. This is the bane of annual agriculture, and traditional vegetable gardening as well. Nature cannot re-supply all of the nutrients we remove fast enough to continue to grow annual plants on the same plot for years in a row. Some nutrients will go deficient and need to be replenished, as I am doing by re-mineralization. Taking soil samples and having them analyzed, then tailoring a re-mineralization to add just what the soil needs, avoids adding excess nutrients, which can cause as much harm as not enough of them. While I hope that over time I can get some cycling of nutrients from the compost pile back into the soil as the weeds I put into them become better balanced, I don’t expect to drop all re-mineralization. To the extent that I can partially close the cycles by using on-site resources like urine and wood ashes, I will do that. It’s probably the best I can hope for, though I would not mind being proven wrong.

Second, I don’t have a good feel for why particular nutrients change in particular directions over time. Possibly an ecologist could explain it, but I have no formal training and not enough informal reading in the field. Among other things, the apparent excess of Ca in 2020 stumps me. Calcium tends to dissolve into the soil water and move with it down into the groundwater, thus being lost to the garden and its plants. Considering the excessive rain we had last year and have had so far this year, I would have expected more than the usual amount of Ca to be lost to the garden and therefore to see a deficiency this year. This is a common frustration in scientific research, just something we garden scientists have to keep in mind as we try to understand what our gardens are telling us – and a good excuse to spend some time with textbooks on ecology or agronomy.

The question now becomes, can I use wood ashes to add some or all of any of the deficient nutrients in 2020?

Since trees take up the same range of nutrients from the soil as do vegetable plants, wood is a potential source of nutrients for re-mineralization. Those of you who add woody mulch to your gardens are at least partially closing the nutrient cycles by doing so. I don’t have a convenient source of woody mulch that I trust to not contain systemic herbicides. Since I have the wood ashes and would prefer to use them rather than landfill them, wood ashes it is.

Wood ashes have a variable composition. A Missouri Extension publication on using wood ashes in the garden indicates that wood ashes contain, by weight, about 1% P, about 5% K, and about 25% Ca. It didn’t mention Mg, but a brief web search brought up an article analyzing the elemental composition of certain hardwoods from forests in England, which indicated that the Mg level in these hardwoods is about 10% of the Ca level. Thus wood ashes are roughly 3% Mg.

In 2020 the soil is deficient in P, Mg, and K, and in excess in Ca. I would have to add about 3 pounds of wood ashes to each bed to correct the entire K deficiency. With an excess of Ca already, this does not strike me as a wise move. So I will add potassium sulfate to correct the K deficiency, which also adds more than enough S to correct the S deficiency. I had hoped to not have to use this soil amendment as it is depleting, but perhaps some years it will not be needed, as it was not in 2019. That would be preferable to adding it every year.

I can add a smaller amount of wood ashes to correct for the Mg deficiency. The Acid Soil Worksheet indicates that I should only add 10% of the amount needed to correct the deficiency this year. Adding more risks getting the Ca:Mg ratio out of whack, which among other things makes for too-sticky soil. I can add about 5 ounces of wood ashes to each bed to correct for 10% of the Mg deficiency without adding more Ca than I am comfortable doing. This also adds a small amount of P and K, but not enough to correct these deficiencies.

Last year I was very happy that the soil had an excess in P, because sources of phosphate are depleting. This year, while I do need to correct a deficiency in P, at least it is less than it has been in any other year with a deficiency. I’ll correct it by using Tennessee brown rock, which has about half as much P as rock phosphate and comes from the washing piles left behind from extracting superphosphate from high-grade ore about 100 years ago.

One other question I’m asking the garden this year stems from my continuing interest in the possibility of increasing the TCEC of the garden soil. Fedco is offering for the first time this year a product called Hum-Amend Max which is touted as doing just this. Given the uncertainty in the precision and accuracy of the test for TCEC, rather than adding it to only one bed and not to the others, I will add it to every bed in 2020 and see if it changed the TCEC enough to notice in 2021. I’ll also observe the garden as I usually do with an eye to noting differences between this year and past years. This may be a one-time addition (Fedco’s write-up indicates that at least part of the formulation is intended to have long-term effects), but I will wait to see the results from this year’s test before deciding if I should add any more in future years.

So that’s what I’m asking the garden in 2020. I wish all of you the best in your own projects! Meet you here again in April.

Wednesday, February 5, 2020

The 2020 garden: further adventures with homegrown nitrogen

In 2019 I engaged in a conversation with my garden, asking it to answer a question I posed to it about the effect of using a homegrown source of nitrogen, aka urine, to replace the cottonseed meal that I had used in the past. A scientist would call my approach a simple application of the scientific method. As I related in the previous post, the conversation amounted to applying the usual re-mineralization mix, formulated to address deficiencies found in the March 2019 soil test and including cottonseed meal as usual as the nitrogen source, on one of the three beds of dent corn that I grew last year. This bed served as the control bed. For each of the other two beds of corn, I made one change in the planting conditions compared to the control bed: for one bed I replaced the cottonseed meal with urine but kept all the other components in the re-mineralization mix the same, for the other bed I used the same re-mineralization mix but planted three days later. When I harvested the corn, I kept the corncobs from each bed in separate locations and shelled each pile of corncobs separately, so that I could measure the yield of the corn that grew in each bed. I also made observations of the plants and the cobs in each bed during the growing season. This allows me to assess what the effect of that single change was on the yield and on any other observable changes among the plants in each bed.

Since I’m working with living plants in a living world, interpreting the results of such an apparently simple test really isn’t that simple. There are quite a few things that might not have been uniform between the three beds. And this doesn’t address more subtle differences, such as the fact that I knew which beds got which treatments, meaning it isn’t even a single-blind test. My hopes for what the test would reveal may have influenced the results. US society officially doesn’t accept that nonphysical causes, such as my thoughts, could have physical effects, but this has been shown to occur often enough in the medical field that only the double-blind test, where neither the patient nor the researcher knows who gets the drug or the placebo, is considered to provide reliable results. Beyond that, a host of other subtle effects are creating considerable difficulties in accepting the results of studies in the medical field. I mention this because I want you to understand why I consider the result to be more tentative than it may appear when you look at the data in the previous post.

Let’s look more closely at why I asked the garden about using urine as a home-grown nitrogen substitute last year. Cottonseed meal works well as a nitrogen source in my garden, and at the moment it’s readily available. And not even from all that far away; I’ve seen cotton fields in far southeast Missouri, and there are plenty in Arkansas just to the south.

But even though it works, and it’s readily available, it comes at a price. The price is most obvious when I pay for it, and when I have to haul the 50 pound bag of meal out of the car and into the basement. But that doesn’t account for other costs incurred in growing the cotton and getting the cottonseed meal to me.

Cotton demands a highly fertile soil. Without adding fertility, cotton-growing will render the soil it’s grown in infertile within only a few years. The fertilizer business demands a lot of diesel fuel and a lot of natural gas to produce the nitrate fertilizers the commercial growers use. (No, I don’t use organic cottonseed meal. There is so little organically grown cotton in the US that it’s prohibitively expensive to buy organic cottonseed meal.) There is more diesel fuel used to power the machinery that prepares, plants, maintains, and harvests the fields, and more used to process the cottonseeds into dry meal, and more to get that meal to me. All of that burned fuel adds to the pollutant load of the atmosphere and contributes to fossil fuel depletion. Any nitrate added to the fields over what the cotton needs to grow adds to the pollutant load of the rivers that drain cotton-growing country, most of which drain to the Mississippi River and eventually into the Gulf of Mexico, contributing to the dead zone there. If I could find a source of nitrogen that is closer to me and eliminates most if not all of the fossil fuel use and associated pollution, I would love to use it. And if in addition it is free and using it avoids a source of pollution, then what could be stopping me from using it?

As it happens, there is a free, local source of nitrogen in a form that plants can use, which requires almost no fossil fuels to collect and apply, and which avoids the more usual fate of that source, where it becomes a problem to solve. That source is urine. It’s free for the collecting and applying, which can be done in a low tech, nearly fossil fuel free manner. As long as I avoid applying more than the plants require for growth and I take precautions to keep it from running off into the local stream, it will be taken up and used and not cause pollution. As long as I only collect it when I’m well, it won’t have the potential to cause illness. Not sending that urine into the sewer system means that it won’t require energy to process before dumping it into the river, nor will any byproducts of that process pollute the river. And using it closes a loop which runs from the land to me and back to the land again. Animal urine is part of the nitrogen cycle that keeps Earth and its beings alive.

A simple calculation I did last year indicated that I generated enough nitrogen in urine to only need to collect and apply it once every 10 days to one corn bed to provide enough nitrogen for that bed for the entire growing season. Then I wanted to know if theory and the physical world are in agreement. Thus I devised and carried out the simple scientific experiment that I briefly described above. Corn is a particularly nitrogen-hungry crop, so if substituting urine for cottonseed meal works for corn, it should work in the rest of the garden as well. The data I collected suggest that urine was a successful substitute for cottonseed meal, with the caveats I mentioned above.

With this information in hand, I will expand the use of urine to the entire garden in 2020. Here I’ll discuss how I’m collecting and applying the urine, how much nitrogen an adult human produces in a day in urine, and how large a garden area that urine can supply nitrogen to.

I have already discussed health and environmental issues to be aware of when using urine. There is also a psychological issue which arises from the known health hazards of urine and from its association with feces: many if not most people consider urine dirty and dangerous and won’t want to eat anything grown with it. Urine is illegal to use on any food crops grown for sale because of the health and environmental risks associated with inappropriate use. If you were to consider using your own urine to supply nitrogen for your own garden (not that I am suggesting you should), you must first ensure that none of the food you grow with it is sold. Second, you must ensure that you yourself, and anyone who is eating the food you grow with it, knows you are using urine and favors its use. Informed consent is just as important in this case as it is in sex and medicine. Third, you must ensure you are applying the right amount, to avoid pollution of surface waters from any excess urine that cannot be used by the soil and the plants.

In my own case, my husband Mike and I favor its use, and I collect it only when I’m healthy. I use a plastic urinal such as are sold in pharmacies for collection (those of you with more exposed genitalia can collect it in any suitable container), dumping the contents into a larger lidded plastic container for storage. I pour the day’s collected urine (roughly 2 quarts) into a 2 gallon watering can and add water to fill the can. Then I sprinkle the contents of the can on whichever 100 square foot bed is to receive the previous day’s urine, following that with another 2 gallons of collected rainwater. The plastic urinal, storage container, and sprinkling can required some oil to make and to ship to me, but no more to use. Since I’m careful to apply only as much urine as the plants need, and I keep that urine out of the local sewage treatment plants, the urine turns a problem – nitrate pollution – into a solution – home-grown soil nutrition, which in turn feeds the plants I grow. The garden is surrounded by mowed grass paths and many square feet of unfertilized groundcover (a mix of lawn grasses and weeds) and trees beyond, so any nitrogen the garden or the grass paths cannot use will be absorbed and used just beyond the garden fence.

How do I know how much urine is the right amount to apply? First, I need to know how much nitrogen the plants I’m growing in the garden require. Agricultural scientists have done exhaustive experimentation to answer this question and produced tables like the one available here (page 8). A glance at the table shows that crops vary in their need for nitrogen, with potatoes and cabbages needing a lot more than, say, turnips. If I wanted to, I could calculate exactly how much urine I should apply to the area of each crop that I grow with the data in this table plus knowing how much nitrogen the average adult urinates in a day plus the square feet taken up by that crop. But in practice, I applied the same amount of cottonseed meal to each bed except for the potato bed, which received twice as much as the other beds. Since I know the weight of cottonseed meal I added to each bed and the percent of nitrogen it contains, I know how much nitrogen it added to each bed. Thus I’ll add the amount of urine that provides the same nitrogen as the cottonseed meal I used previously, except that I’ll add twice as much urine to the potato bed as I do to the other beds. In later years I will consider refining how much I apply according to the nitrogen need for each particular crop.

Here is the calculation I did in case you are curious about how you could do this in your garden (not that I am suggesting it, of course). From Steve Solomon’s book The Intelligent Gardener and the current version of the worksheets in the book, which you can find here, we note that the percent nitrogen in cottonseed meal is given as 6%. Since I know that I apply 6 pounds of cottonseed meal to each bed (12 pounds to the potato bed), the amount of nitrogen in the cottonseed meal is:

6 pounds * 0.06 = 0.36 pounds of added nitrogen to a 100 square foot bed
12 pounds * 0.06 = 0.72 pounds of added nitrogen to a 100 square foot bed of potatoes

In order to know how much urine to apply to each bed, I need to know how much nitrogen an adult human produces in that person’s urine in a day. Carol Steinfeld in Liquid Gold tells us that adult humans produce about 11 grams of nitrogen in a single day’s urine. Since there are 453 grams in a pound, if I divide 11 grams by 453 grams per pound, I will get the amount of nitrogen in a day’s urine in pounds: 

0.024 pounds of nitrogen excreted in urine each day

Now you need the length of your growing season in days; that multiplied by the amount of nitrogen in urine per day tells you how much nitrogen your urine can supply during the growing season. My growing season is about 180 to 200 days long. Using 180 days for my growing season, here is how much nitrogen I can supply to the garden if I collect it every day and apply all of it over the course of the growing season:

180 days * 0.024 pounds of nitrogen per day = 4.3 pounds of nitrogen

Above we found that each 100 square foot growing bed needs 0.36 pounds of added nitrogen, or 0.72 pounds if it is growing potatoes. If I divide 4.3 pounds of nitrogen by 0.36 pounds needed per bed, I know how many 100 square foot beds a growing season’s worth of urine will supply with enough nitrogen for good growth:

4.3 divided by 0.36 = 12 beds

I grow a total of 9 beds of vegetables and grains in the vegetable garden. Since the potato bed needs twice as much nitrogen as the other beds, then I need to supply the equivalent of 10 beds. I have 12 beds’ worth of urine, so I can supply all the nitrogen my vegetable and grain beds need over an entire growing season on just my urine. In my day planner I will keep track of which bed I add each day’s worth of urine to. In practice, each bed only needs urine applied when it has plants growing in it that haven’t been fully harvested, and I won’t apply urine any time the soil is soaked from rain, so I will add somewhat less than I have calculated above. I’ll keep track of yields as I always do and also observe each crop as it grows and make notes about any changes compared to what I’ve seen in past years. And I’ll report the results in 2021.

Besides this conversation, I’ll engage in some others. One of the questions I’m asking the garden in 2020 will be if it makes sense for me to direct-seed lettuce and some cabbage family crops in spring instead of growing and planting seedlings. Mike and I have been eating salads almost every day, but I haven’t been growing enough salad crops to supply anywhere close to what we are eating. I’d like to see if I can do better this year by direct-seeding and eating thinnings. I’ll try two separate sowings of these crops in spring, to see if I can prolong the spring salad season. I’m also trying to grow endive this year and some different varieties of crops than the usual ones I grow. And with that I’ll leave you till next month and wish you bountiful harvests in 2020!

Thursday, January 23, 2020

What the 2019 garden told me

Cabbages happily growing in early June 2019

If you have been reading my blog for awhile, you will know that I grow a vegetable garden and that I strive to grow as high a yield as possible of delicious vegetables in a limited space, in the most sustainable manner possible. Toward this goal, each year I develop one or more questions to ask the garden to answer through applying the scientific method to my gardening practice. The big question that I asked my garden to answer in 2019 is if the urine that I produce as a byproduct of being alive can provide sufficient nitrogen to grow dent corn in place of using cottonseed meal as I had been doing. And I’ll get to what the garden told me in due time.

As usual, the garden also told me the answers to some other questions that I hadn’t asked. So let’s start by examining the weather during the 2019 growing season to learn how the weather affected the vegetable garden. Then we’ll examine the data that I collected on yield, which is one of the ways the garden communicates with me, to learn how the garden responded to the weather and to the test that I set up. Finally, I’ll share observations I made on taste and pest issues with some crops for my own use and for those of you who also grow these crops in your gardens.

I can describe the weather in 2019 in one word: wet. St. Louis has not experienced such a consistent excess of rain across the growing season since 1993 – and as in 1993, the rivers flooded in response. The Mississippi River at St. Louis was at or above flood stage for 127 straight days from late March through late July!

The flooded Mississippi River backed up Watkins Creek and covered the Coal Bank Road overpass on June 8, near where I live. This is about a half mile upstream of their confluence.

Here’s how much rain the garden received in each month of the growing season compared to the average for each month as reported by the St. Louis NWS office. Because freezes in March and November would split the plastic rain gauge I use, I reported the value measured at the official site for St. Louis for these two months. The values for the other months are totals of what I measured in my rain gauge during rain events in that month. 

Notice, first, that the only month in which our garden received significantly less than average rainfall was September. Second, note the astonishingly large total rainfall in August. Almost half of this, at least 5.5 inches of rain, occurred in a single storm event on August 12! This was about double what the official recording station received during the same time period. Nor was this our only rain event of this size; 5.0 inches of July’s rain fell in a single storm event on July 22, and this was about 50% more than the official recording station received.

Given this much rain, I feared that the excessive rainfall and accompanying humidity would reduce yields in general due to waterlogged soil. In fact, while the yields of some crops were lowered, other crops yielded as well as or better than they usually do. This suggests that while what I considered excessive rainfall may have had a negative effect on some crops, other crops do well, perhaps even better, with very moist soil. I’ll discuss this more in the reports on individual crops.

Concerning temperatures, spring tended to be cool, with the last frost occurring on April 15. A period of particularly cool weather occurred from May 9 to 14, when I was planting some of the summer crops. Seeds that I planted during this time failed to germinate and needed to be re-seeded. Summer temperatures averaged to near normal while September proved to be much warmer than normal, as well as drier. October averaged a little cooler than normal, but the usual wide autumnal temperature swings produced an early frost on October 12 and a hard freeze of 25F on November 1, for a growing season of 180 days, two or three weeks less than average. Based on temperature, spring crops would yield about their average, summer crops would yield better than average (because our average summer weather tends to be hotter than most of the crops other than corn prefer), and fall crops would do poorly. Most crops fell roughly in line with these expectations, with notable exceptions being peas, beans, eggplants, cabbage, winter squash, and zucchini, all of which yielded less well than I would have expected.

Below you’ll find the data for each crop that I grew in 2019.

Rather than discuss each crop or group of crops in detail, I’ll only mention those that answered particular questions that I asked the garden or that the garden asked and answered. If any reader has a question that you’d like answered about any of the crops, please feel free to post it in a comment and I will respond by the time I put up the next post.

First, the muskmelons. I spent years trying to grow ripe muskmelons on the ground or on vertical trellises, with no success. Other area gardeners as well as farmers grow them, however, so I decided to try them once again. In 2019 I grew them a new way, on an A-frame trellis, thinning to two plants on that trellis. 

The A frame trellis on which I grew the melons is near the center top of the photo, just in front of bok choy plants. Moving toward the viewer are rows of kale, cabbages, collards, and lettuces. The next bed to the left holds potato plants. This photo was taken on May 25.

Those two plants produced eight ripe melons over a month long span! They were planted on the same day as the winter squash, but the melons performed much better than the winter squash and the zucchini planted about 10 days later. The latter two grew on the ground compared to the trellised melons. I wonder if getting the melons off the ground may have been key to their better growth and yield during the excessive rain and humidity of the summer of 2019. Also, melons are a moister crop than winter squash, so I think melons would benefit more from consistently moist soil than winter squash. Given how well the melons did in such a wet growing season, I plan to favor them with any irrigation I need to do during future growing seasons.

Second, the sweet peppers and tomatoes. Both varieties of sweet peppers yielded as well as they did in the best previous year, 2015. Both 2015 and 2019 featured excessive rainfall; 2015 was a little warmer than usual, 2019 a little cooler. I conclude that sweet peppers, like melons, benefit from consistently moist soil; I will also favor them when irrigating in future years. Also, while the ‘Purple Beauty’ bell peppers yielded very well, I found them to not have as good a flavor as ‘World Beater’ when ripe. As for the tomatoes, their yields were higher than I reported because we were out of town during the couple of weeks when they first ripen. I gave a friend permission to harvest all the tomatoes that ripened while we were away from home. While she didn’t weigh them, she reported that she harvested many tomatoes! Still, I’ve noticed in past years that tomatoes suffer during warm, wet conditions, so they probably didn’t yield as well as usual in 2019.

Third, the kale and collards I tried to keep going through the summer. In past years harlequin bugs attacked cabbage-family crops like kale and collards that I left growing after late July, so I got in the habit of removing them then, a few weeks before planting the autumn crops. In 2019 the weather was cool and moist enough I decided to leave the kale and collards in the ground. Wrong move. By the time I planted the autumn crops, the kale and collards were being attacked and eaten by a caterpillar that I could not identify. Sometime in October I realized I should have taken some of the caterpillars to the Missouri Extension Service desk at the Missouri Botanical Garden so their experts could identify them, which may have helped me learn how to control them. By that time the caterpillars were gone … but before then they had moved over to the seedlings and fed freely on them, setting them back. Add that to the hot, dry conditions in September that these plants dislike and none of the autumn cabbage-family crops did well. May I learn this lesson for good this time.

The kale looked great on June 24, before the caterpillars attacked

Fourth, the dent corn. I wanted to know if I could substitute my urine for the cottonseed meal that I had used before as a source of nitrogen, so I designed an experiment for the garden to provide me with an answer. Because of the excessive rain and cool weather in May, I had to delay planting the corn until the beginning of June. Then a too-short dry spell meant I could only plant two beds on the same day. So I made a change in the experimental plan. As in the original plan, I used cottonseed meal on Bed 5 (the control) and urine in place of cottonseed meal on Bed 4, keeping the other added amendments the same (the experiment). For Bed 6, I used cottonseed meal and the same amendments, so in this respect it was treated the same as the control bed, except that it was planted three days later. The later planting made it an experimental bed as well, with the variable being the planting date. 

The three beds of corn on August 11. Bed 4 is the two rows to the left; Bed 5 is the two middle rows; and Bed 6 is the two rows on the right. There are no visible differences between the plants in the three beds.

You will notice that the results are the same for all three beds (the kitchen scales I use to weigh the crops are precise to two significant digits) and better than the results from 2017, a much drier growing season than 2019. I conclude that urine was successful in replacing cottonseed meal as a source of nitrogen, the significance of which I’ll discuss in the next post. I also conclude that corn is another crop that benefits from consistently moist soil.

With that, I will return you to whatever else you need to do, and I will return to completing the 2020 garden design. When next we meet, I’ll let you in on what I plan to ask the garden in 2020.