Wednesday, December 10, 2014

What I learned from my garden in 2014

Two years ago, John Michael Greer posted A Wish List for Krampus to his blog TheArchdruid Report. After describing three technologies that he suggested would make the transition to a post-industrial, low-energy future a little less difficult, he asked his readers with scientific and engineering backgrounds to make suggestions of their own. To offer extra motivation, he set up a contest: formulate a post discussing a problem we’ll need to deal with or a solution to one of the challenges facing us as we undergo energy descent, post it by November 1, 2013, and he’d consider it for inclusion in a book of the best such entries. We, his readers, called it the Krampus contest after the post’s title.

Around this same time I was considering a worrisome trend in my vegetable garden. For the past few years I had noticed declining yields and an increase in pest and disease issues. I wanted to understand what had happened and what needed to change. With the Krampus contest as motivation it was a good time to re-invigorate my garden and my gardening practice by applying the scientific method to this challenge and and showing other people how they might do the same. Since I’d been working with Ecology Action’s method of gardening for over a decade and had David Duhon’s book One Circle which proposed sample minimum-area plans to produce a complete diet on a backyard scale, I could grow the crops featured in the plans to find out how well the proposed plans met the conditions, personal and environmental, that I deal with. Since I suspected that one cause of my garden’s languishing might be an imbalance in the soil mineral profile, I had a hypothesis to test, and with the help of Steve Solomon’s newly published book The Intelligent Gardener and a soil test I would know how to re-balance the soil minerals. Not only would the yield data that I collected help to determine if a complete-diet garden could be grown in the greater St. Louis area in the space suggested by Duhon, but by showing my work -- by using the scientific method to formulate a hypothesis about soil re-mineralization and then testing the hypothesis against the data that I gathered -- I could become a better gardener and show other interested gardeners how to do likewise. And in the process, I might improve the garden soil, the vegetables that I grew from it, and the health of the two people eating those vegetables.

This post was my entry for the Krampus contest. This post applied the same method to the other crops that I grew in 2013. While the contest did not elicit enough entries for the book to be pursued, taking part in it proved valuable to my gardening practice. Thus I continued my gardening science project in 2014 with new hypotheses and promised to publish yield data and evaluate the results at the end of the growing season. It’s that time, and here they are.

For those of you who are unfamiliar with the scientific method, it starts with a problem that you’d like to solve. In my case, I want to know if either or both of two of the complete-diet garden plans that Duhon proposed in One Circle can be grown successfully here; more specifically, can I obtain the required yields for each plant in the garden designs? In order for the gardens to be grown in the space Duhon allots for them, the yield (weight per unit area) of each crop grown in them has to meet Ecology Action’s mid-range yield. Most of the crops I had grown had not achieved this yield most years, thus the specific form of my question.

In order to apply the scientific method to my question, I put it in the form of hypotheses, statements that can be evaluated by data such as yield (weight per unit area) of the harvest, insect damage, and taste which I collected for each crop that I grew. Gardens are living systems so the garden and the larger living system in which it is embedded asked and answered some of its own questions. As a gardener-scientist, my task is to look at the data that I collected, not only in light of the hypotheses I formulated to guide the work, but also to understand the questions that the garden asked and answered and how those interacted with the hypotheses. Doing this well will allow the garden and me to work together to grow delicious food in a way that respects the soil and its life, the lives of the other beings that share this bit of land, and the larger cycles that the land and its inhabitants participate in.

Let’s look at some natural events that shaped the garden in 2014. Our last spring frost occurred on April 15 and the first fall frost occurred on November 1 for a growing season of 198 days, about average for this area. April, May, and June were warmer and wetter than normal while July was cooler and drier than normal. August overall was warmer and wetter than normal; however, while the first half was cooler than normal, the second half (and the first week of September) brought the hottest weather of the season. Once the heat passed, the rest of the growing season was cool and wet. Before factoring in any of my own questions, then, we can hypothesize that weather conditions in 2014 might favor spring and fall crops over crops that require a long period of hot weather and might favor crops that prefer wetter over those that prefer drier growing conditions. We can also hypothesize that crops that compete well against disease might be favored over crops that compete less well against disease, since wet growing conditions tend to favor many diseases that affect vegetable crops.

Besides the weather factors, some personal factors affected my gardening in 2014. As I noted in this post, I spent more time at lawn-mowing during May and June than I have done in previous years. This reduced the time I spent weeding to the point where some of the spring crops failed from being out-competed by weeds. The increased weed growth required me to spend more time than usual preparing each bed for cropping, slowing down planting, until around the end of June when I learned how to use a scythe to hack off weedy growth rather than trying to hoe off tall weeds. Then I found out that I could dig the root-filled bed much faster with a shovel than with a broadfork. However, soon thereafter I spent three weeks away from home on family business. By the time I returned home at the end of July, I faced garden triage. I responded by ensuring that the full-grown spring crops needing harvesting got it and that the fall crops got planted, thinned, and weeded on time, leaving the long-season summer crops that I had managed to plant to face the weeds on their own and leaving the remainder unplanted for lack of enough growing days left for them to mature.

Because I suspected that my garden soil was not properly balanced for minerals and that the imbalanced minerals might be a major factor reducing the yields I have been able to achieve, I have focussed on evaluating how yields have responded to efforts to properly balance the minerals in the soil during the past two years. The hypotheses I made for the 2014 garden before the season began, based on my continuation of the soil re-mineralization work, were:
            1. Pest and disease pressure will be no worse in 2014 than in 2013;
            2. The taste of those varieties that I grow every year will show further improvement over that observed in 2014; and
            3. Yields will increase, or at least not decrease, for those varieties that I have grown in the past.
In each case a positive answer would suggest that soil re-mineralization had a positive effect on that particular crop. If enough crops responded positively I would consider continuing with the soil re-mineralization program in 2015. If, however, some or most of the answers were negative I might reconsider if soil re-mineralization would be beneficial in 2015. Note that I need to account for any effect of the weather and personal factors on yield as well. All these factors will figure into the discussion of individual crops and the overall results.

I also performed small trials for some crops, in some cases testing different varieties, in others different spacings, to look at how those changes affected yields and tastes. I’ll also mention what I learned from these trials in the write-up for particular crops.

In Table 1, below, I give the 2014 planting data for the crops that are included in two prototype garden plans that provide a complete diet from the book One Circle; they are in turn based on the work done at Ecology Action and described in their popular gardening guide How to Grow More Vegetables (HTGMV). The first two columns show the crop and the variety grown. Because the garden plans in One Circle depend on the methodology and crop spacing in HTGMV, I have included the spacing suggested by HTGMV for each crop in the third column. The fourth and fifth columns indicate the spacing I used and the date of planting for the year in which I obtained the highest yield for that crop prior to 2014. This data is important because in nearly every case I grow at wider spacing and in a square or rectangular grid rather than HTGMV’s triangular grid and because planting at the optimal time is required to obtain the highest possible yield. I used the highest previous yield I’ve obtained in order to assess the hypothesis about yield changes resulting from re-mineralization.

I also grew a number of other crops, because we and many other people like them and because some of them may eventually become part of my own complete-diet garden plan when I have enough reliable yield data to make an attempt at a design. Table 2 shows the same information as Table 1 for these other crops.

Table 3 gives the yields, in pounds per 100 square feet, that I obtained for the crops included in the northern version of One Circle’s complete-diet garden plan. The assumed yield in the second column is from One Circle and corresponds to the mid-range yield given in the HTGMV edition in print at that time. Duhon assumes that a gardener of intermediate skill who follows HTGMV’s method should be able to obtain the mid-range yield. Thus he uses the mid-range yield to derive the area required for each crop in his complete-diet plans. The third column is the best yield I have obtained for that crop before 2014; the fourth column is the 2013 yield; and the fifth column is the 2014 yield. Where necessary I have shown the variety for which I obtained the measured yield. 

Table 4 gives the yields for the crops included in the southern version of One Circle’s complete-diet plan. 

Table 5 gives the yields obtained for all the other crops I grew in 2014 that were successful. For the crops in Table 5 the assumed yield is the mid-range yield from the 8th edition of HTGMV.

With all this data at hand, let’s look at the hypotheses I made before the growing season began, to see how the garden answered my questions.

1. Pest and disease pressure: as in 2013, I noticed little of either, remarkable for a year in which disease pressures would be expected to be high due to excessive rainfall and humidity for almost the entire growing season. One variety of tomato, ‘Rose’, succumbed to disease in August, but all plants of each of the other three tomato varieties remained alive and producing until the first fall frost. All the pepper plants remained alive and producing till frost, as was true in 2013 and a marked change from high pepper plant mortality for a number of years preceding 2013.

2. Taste: I did not notice any further taste improvement in 2014 for those varieties that I grow every year - but neither did I notice any worsening of taste.

3. Yield: this is dependent on a multitude of factors considered in the posts describing the 2013 results. Among these are weather, soil moisture, spacing, mineral levels, weed pressure, pest and disease pressure, planting date, and variety grown. While some of these are within the control of the gardener, some of them are not. Some of those that could be controlled might not be controlled for various reasons, such as the personal factors that affected my garden this year. Assessing the yield hypothesis, then, requires a close examination of the planting information, the yields obtained, and the weather and personal factors that might have affected each crop. Thus I’ll discuss each of the crops that I grew in 2014 separately, starting with those in Tables 1, 3, and 4 (the crops used in One Circle’s complete-diet garden plans) and then those in Tables 2 and 5 (everything else I grew in 2014).

Garlic: note that the yield of the variety grown in both 2013 and 2014, ‘Inchelium Red’, increased by a factor of 3 in 2014 versus 2013 and is now the same within experimental error as the best yield previously obtained. I consider this as a yes answer to the yield hypothesis because my care of the garlic patch differed little in the two years and weather patterns were favorable both years. Note that a different kind of garlic first grown in 2014, elephant garlic, yielded at One Circle’s assumed level despite the wider 6” plant spacing I use. I do not know if elephant garlic has a similar nutritional profile to other kinds of garlic, but I do know that we liked its taste as much as ‘Inchelium Red’. I plan to grow a larger area to elephant garlic in 2015 for further evaluation.

Sunflower seeds: the crop failure was due to too-old seed not germinating. I plan to grow a small area in sunflowers in 2015 but will need to consider how to protect the seeds against bird and squirrel predation.

Potatoes: although the growing season was favorable for temperature, excessive rainfall, excessive weediness, and a late harvest may have reduced the 2014 yield. In addition, the latest revision to Steve Solomon’s soil re-mineralization program, available here, suggests that the soil for growing potatoes might need to be balanced differently from the rest of the garden. I will consider doing that in 2015. I found it surprising that the closest spacing produced the best yield, but then again the best yield I have ever gotten (for a different variety) was for the even closer HTGMV spacing. This suggests growing at the 12” spacing in 2015. I might trial another late-season variety against ‘Elba’. It’s worth noting that ‘Elba’ stored very well; the potatoes remaining at the beginning of December were as firm and tasty as those we ate just after harvest. I stored them in an open bushel basket in the coolest, darkest part of the basement.

Onions: the 2014 growing season weather was favorable for onions, plus I chose intermediate-day varieties (a better match to 39N latitude than long-day onion varieties, I suspect), planted them at the right time, weeded them a couple of times before I had to attend to family business, and harvested them at the right time. The yields of both red and yellow onions were double that of 2013’s red variety. While still not close to the assumed yield, at least it has improved. If I planted at the closer HTGMV spacing the yield might improve further but the extra time required to plant and weed at such close spacings makes that impractical in my opinion. The yield of potato onions also improved in 2014 versus 2013 for the same spacing and now meets the best previous yield. Thus the yield for potato onions answers yes to the yield hypothesis, while the yield hypothesis cannot be assessed for red and yellow onions because I grew different varieties in 2014 versus 2013. We liked the taste and size of both the red and yellow varieties and they are storing well with very few lost to rotting or sprouting; they will become my new standard bulb onions.

Turnips: the much higher yield for 2014 compared to 2013 is most likely due to the better fall growing conditions and more timely planting, thinning, and weeding in 2014 versus 2013. While the 2014 yield is still below my best yield, the best yield was obtained with rows grown half the distance apart. It may be worth doing that in 2015.

Parsnips: the crop failure in 2014 appears to have been due to low germination in the seeds used. I tried a different seed supplier for some of the biennial crops I grew in 2014 and noted poor germination in many of them. I will use a more reliable seed source for this and other biennial crops that I grow in 2015.

Sweet potatoes: this crop failed due to excessive weed pressure choking out the crop. I did not weed them at all, not noticing that the plants grow slowly at first and need to be weeded until they are well established.

Peanuts: this crop failed due to rabbits eating it while I was out of town.

Leeks: the seeds arrived too late to start in a flat and had to be direct-seeded to the garden, with spotty germination the result. I also let them get too weedy over the summer. Still, the yield was about the same in 2014 as in 2013, which at least does not negate the yield hypothesis. Because of the spotty germination in 2014 and the wider crop spacing I cannot compare the 2014 yield with the best yield I had previously obtained for this variety.

Looking at the crops in Tables 2 and 5, among those whose yield improved in 2014 compared to 2013 are arugula, sweet peppers, winter radish, and winter squash. In the case of arugula and winter squash, the 2014 yield also exceeds the previous highest yield. The 2014 yield for hot peppers also set a new record but that variety was not grown in 2013 so the yield for those two years cannot be compared. Some crops yielded about the same in 2014 compared to 2013; these include cucumbers, the spring crop of ‘Bronze Arrowhead’ lettuce, spring and fall bok choy, and snow peas. All these crops either support or do not contradict the yield hypothesis.

Now let’s look closely at the crops which appear to contradict the yield hypothesis, to see if other factors from the 2014 growing season can account for the reduced yield compared to 2013.

Of these, tomatoes stand out. The yield in 2014 was about half that of 2013. I think this can be explained by the cool, wet July and early August weather, conditions less favorable to tomatoes. The yield for both varieties in 2009, another year with a cool, wet summer, was the same within experimental error to the 2014 yield, while the yield for 2012 for ‘Arkansas Traveler’ was a little higher than that for 2013, a year with a similarly hot and dry summer. Thus I suspect that the reduction in yield for 2014 versus 2013 was largely accounted for by the difference in weather conditions. (For the paste tomato, the very high yield in 2012 may have been due to caging rather than staking the tomatoes. Caged tomatoes generally yield more per unit area but shade neighboring crops more.) The new variety I tried, ‘Pale Perfect Purple’, looked good and tasted good, but not good enough to earn it a permanent spot in my garden.

For broccoli, my 2014 planting plan was too complex; I found it difficult to tell what variety most of the plants were once they grew large enough to touch. While I was away I told Mike not to record the harvest data, since he would be unable to attribute it to the right variety. The 2014 broccoli yields are too low due to this error, thus the yield hypothesis cannot be assessed. Nor can I assess differences among the varieties.

For bok choy, all the plants of the ‘Chinese’ variety bolted in spring before they achieved any size. ‘Prize Choy’ plants also bolted but later, after they had sized up, so they provided usable food at about the same yield as in 2013. A couple of the fall-planted ‘Chinese’ variety also bolted but none of the ‘Prize Choy’ plants bolted; yields were about the same within experimental error. I’ll continue to grow ‘Prize Choy’.

For spring lettuce, ‘Anuenue’ bolted before I could harvest half of the heads, compared to 2013 when I harvested all the heads before they bolted. Checking weather data for both years during June, the critical month for the lettuce harvest, both years were wetter than normal; however, for temperature, June 2013 was average while June 2014 was warmer than normal. Thus, weather may account for the lower yield. I found that ‘Jericho’ tip-burned too much, thus I will not continue growing it. We liked the butterhead lettuce I grew, ‘Butter King’, and I may grow it again next year. The highest-yielding lettuce in 2014 was ‘Pablo’; as a pretty, long-standing lettuce with a good flavor, it has earned a space in my garden. I think reducing the growing space for spring lettuces to half that of 2014 will result in a much higher proportion of lettuce eaten before it bolts.

The fall lettuce garden failed. There was little germination and rabbits ate what few plants grew. I rarely have success with fall lettuce seeded directly to the garden, probably because the soil is too warm in August. In 2015 I’ll try sowing seeds for the fall crop to a flat held in the basement in early July, bringing the sprouted plants out to a shady location to grow on and planting decent-sized seedlings to the garden in August.

The weather patterns noted above for spring lettuce may have affected cabbage similarly. For both 2013 and 2014 ‘Golden Acre’ cabbage yielded twice as much as ‘Early Jersey Wakefield’ and was ready to pick at about the same time. Thus I’m switching to ‘Golden Acre’ for summer cabbage. For fall cabbage, ‘Early Flat Dutch’ started on April 10 and transplanted to the garden on April 22 with just two true leaves resulted in excellent heads harvested during the second half of August, a time when I had no other leafy greens available. I’ll grow it again and may try an even later variety as well.

For the peas, I think not weeding before or after planting reduced the potential yield in 2014. Pre-sprouting the peas helped (I may not have gotten any peas without those extra few days to grow through the weeds) but the support system I tried did not seem very effective. I have an idea for a better support system to try in 2015.

For zucchini, I think I grew more plants per unit area in 2013 than in 2014, but I did not note that specifically on the data sheets I keep for each crop. I need to keep closer track of how many plants I grow per unit area for these and winter squash. Also, zucchini may have been negatively affected by the cool, wet conditions of July and early August when most of its fruits set, while the winter squash, which was planted later and flowered later, may have benefitted from the warmer conditions of the second half of August and early September.

For squash, I only planted ‘Waltham Butternut’ as I ran out of time to prepare the bed for the other variety I planned to grow. And I did not plant the squash until much later than I had planned. Even so, the yield beat the previous best and the quality of the squashes is excellent.

For cucumbers, the trellising system seemed to perform well enough, but I think I can improve it in 2015. The melon crop failed yet again; the vines succumbed before they ripened a melon. I did not have time to prepare the area that was to grow the watermelons.

For popcorn, the yield in 2014 will be poor. Because I did pre-planting preparation on three different days but planted all the beds on the same day, the effects of excessive weed pressure are apparent. In the bed prepared first the weeds had almost a week’s head start on the popcorn seeds, while I planted the bed prepared last on the day after it was prepared, with the middle bed in between. I did not weed any of the beds all season long. The result can be seen in the photo at the top, in which the harvest is grouped by the bed in which it grew. The largest harvest by far is from the bed planted a day after preparation (the group of cobs on the far left), with the smallest harvest from the bed planted a week after preparation (the group of cobs on the far right). This is a clear indication of the negative effect of excessive weed pressure on yield and overwhelmed the influence of any other factor on the yield for popcorn. Similarly, I did not weed the dry bean bed at all after planting the seed and its yield is likely to be negatively affected, based on the volume of the harvest compared to the volume from past harvests. I did not grow black-eyed peas or soybeans due to running out of time to plant them while there were enough days left in the season to grow them.

For winter radishes, I grew at double the row spacing in 2014 and planted three weeks later compared to the previous best year, so it is not surprising that the 2014 crop did not manage to attain the previous high yield - but it did beat the 2013 yield, which I suspect is primarily due to favorable fall weather and timely weeding and thinning (the same factors that resulted in the high yield for arugula). I did not anticipate that daikon radishes would yield so much better than ‘Red Meat’. I’ll still grow ‘Red Meat’ because it is both pretty and tasty, but I will also grow daikon radishes. I’ll also strive to plant both kinds of radishes earlier as this might be key to obtaining higher yields.

The eggplant, carrot, and beet crops failed due to weeds shading them out. All three of these crops grow slowly and need timely weeding to produce well, which I did not provide. Rutabagas grew well until late summer, when they rotted. They probably need to be planted in late July so that they mature in cooler fall conditions.

Overall, then, it appears that soil re-mineralization had enough of a positive effect on enough crops that I will consider continuing re-mineralization in 2015. Putting the results for both 2013 and 2014 together and combining that with some other changes in the garden and my gardening practice since the beginning of the project suggests I’ve learned some things pertinent to the larger goal of growing a complete diet in a sustainable way that I will discuss in the next post.