What I learned from my 2015 garden

Once again in 2015 I put on my garden scientist hat and went into the garden to plant, observe, ponder, harvest, weed, curse, and wonder. Like any year, it had its highlights, its low spots, and its head-scratchers. Here I’ll let you all in on the fun (it was fun, sometimes, when it wasn’t exasperating) while trying to keep it fun for you to read. Am I up to it? If you read on, you’ll soon find out.

2015: the summary

For the past three years I have been conducting a scientific experiment in my vegetable garden to determine how the garden responds to soil mineral balancing as described in Steve Solomon’s book The Intelligent Gardener. I based the amount of the mixed amendments that I used in 2015 on the discussion I had with a gardening mentor, as I mentioned in this post, and followed the planting instructions for potatoes that are also discussed in that post. In addition, in 2015 I increased the amount of space I allowed for some crops to match more closely to the semi-intensive spacings in Solomon’s book Gardening When it Counts, and I trialed some new crop varieties and planting procedures. But I didn’t do one thing that my gardening mentor had also suggested. Because I hadn’t purchased enough cottonseed meal in early spring to use for side-dressing, I was unable to side-dress the long-season, high-demand crops as he had suggested.

With that said, here’s a summary of garden performance in 2015

1. In general, crop yields remained the same or increased compared to the past two years. For a few crops yields increased by large factors. A few crop yields decreased compared to previous years.

2. The primary reasons for the year’s overall good results appear to be enough nitrogen (except in those cases where I should have side-dressed the crop but did not), starting seeds for the fall leafy greens crops inside and transplanting out seedlings, and attention paid to planting at the proper time and prompt weeding along with the ongoing soil re-mineralization program. Rabbit predation and excessive rain at the wrong time or no rain at a critical time seemed to be the main reasons behind lowered yields.

For those of you who enjoy digging into the details behind the summary, make yourselves comfortable and let’s start digging!

2015 in detail

The most remarkable feature of 2015’s weather was the amount of rain we got. St. Louis set a new record yearly rainfall of 61.24 inches in 2015. That included the setting of two new monthly rainfall records, for June (13.14 inches) and December (11.74 inches). Besides excessive rain and associated humidity, June also was warmer than normal and much cloudier than normal.

Otherwise, after a cold February and early March, the rest of March was warm and about normal rainfall. April was wet and on the warm side, May was warm and on the dry side. July and August were drier than normal overall (although the first half of August was wet) and about normal temperatures. September and October were both warmer and much drier than normal, while November was warmer and wetter than normal. The last spring frost was on April 4, a little earlier than usual. While we experienced a very light frost on October 18, it didn’t have any noticeable effect on the garden. The first fall frost that made a difference wasn’t until November 20, three weeks or so later than usual. Overall, it was a longer and warmer than normal growing season, with a wet spring and early summer and a dry late summer and fall.

The spreadsheet on the four pages below compares the 2015 yields with the best yield I have obtained so far for each crop type I grew in 2015. I’m using the English system of units because that’s the system used for everyday purposes in the US where I live.

The first two columns on each sheet give the crop and the variety. The next three columns show the date planted, the spacing used, and the yield for the best year’s yield previous to 2015. The next five columns give the data for each crop variety planted in 2015. From left to right these are the date planted, the spacing, the total area planted to that crop, the weight harvested from that area, and the yield calculated from the previous two columns and expressed as pounds per 100 square feet. In some cases I grew different varieties of a particular crop during the best year compared to 2015, so in those cases data is given only for the year that particular variety was grown. The final column has brief notes for some crops.

I think it will be easiest to delve into the details if I group crops together into families, since crops within a family tend to be planted and harvested around the same time and have similar needs.

Onions, leeks, and garlic

I grew two intermediate-day bulbing onions in 2015, both raised from seeds. One reason for the decrease in yield in 2015 compared to 2014 was that I planted the rows twice as far apart in 2015, so I only planted half as many seedlings. I also started the seeds and planted the seedlings a little on the late side, so the onions may not have sized up as much as possible under the best of conditions. The best of conditions was not what they experienced in 2015 with the excessive rain in June, when the onions were bulbing. Some of the crop rotted in the field. Finally, the dill I planted next to the end of the red onion area grew huge in the fertile soil and fell over onto the onions close to it, shading them excessively. I was probably lucky to get as many bulb onions as I did in 2015.

Like the bulb onions, the leeks were started and planted late. In addition, the 2006 leek seedlings were planted much closer together (6 inches apart on hexagonal spacing versus 6 inches apart in rows planted 12 inches apart in 2015). A large fraction of the yield decrease in 2015 is likely to result from that. Another issue was that I planted cilantro in the fertile soil next to the leeks, not realizing that the cilantro would grow huge. The cilantro plants proceeded to fall on top of the leek seedlings, shading them excessively. But the leeks that I did get were huge!

Potato onions, like shallots, split into a cluster of separate bulbs as they grow. The cluster is harvested, allowed to dry, then split into separate bulbs for kitchen use. The bulbs look and taste like yellow onions. Potato onions and garlic are fall planted, grow during fall and spring, and are harvested in early June in these parts. I had decent but not complete survival of the potato onions over winter since I mulched part of the plot too late, after the soil had frozen and then partially thawed. Luckily I acted fast enough in June to get the whole plot harvested in between rains and before the really heavy rain fell in the second half of the month. The wet soil may have cut down some on the yield in 2015 relative to the best years but I still got more than enough of these crops.  In fact, I planted much too large an area to potato onions in 2015; we have far more than we’ll use. I planted about half that area to potato onions this past November for 2016.

Cabbage-family crops, spring

In this part of the US these crops are planted in spring to mature in summer or in late summer to mature in fall or early winter. The three of these that I plant as spring crops for summer harvest are cabbage, broccoli, and bok choy. With the good spring and summer weather (warm and plenty of rain!), cabbage and bok choy did especially well. The cabbage yield was a little lower in 2015 than 2013, but I planted it farther apart in 2015 so I grew fewer plants. The 2013 cabbages averaged 2 to 3 pounds each while three of the four 2015 cabbages weighed 4 to 6 pounds each! The fourth cabbage would have weighed about the same, but it began to rot so I had to harvest it two weeks ahead of the other three. All four cabbages were delicious!

I also tried planting storage cabbages in the spring to mature in fall but they rotted in late summer. Based on the success of summer-sown and fall-planted bok choy as noted below, next year I’ll do the same using an early maturing storage cabbage.

The spring bok choy crop yielded about the same as the best year. I don’t think it’s possible to do better than this here, because spring-planted bok choy inevitably bolts (flowers and goes to seed) in early June. But we like it very much as the base of a stir-fry, and it’s ready before lettuce or cabbage, so it is well worth growing in spring. This year’s broccoli was both a different variety and spaced farther apart than the best yield so its yield looks low in comparison, and it didn’t seem to size up as well as the best one I’ve grown.

Cabbage-family crops, fall

Except for bok choy, which I grow in both spring and fall, I grow a different set of cabbage-family crops in late summer and fall. These include turnips and winter radishes and leaf crops such as arugula, kale, and mustard greens.

Turnips and radishes are always direct-seeded. Success with them is highly dependent on their not being a heat wave in the first half of August, when I need to sow them in order for them to mature before winter. This year worked well in that regard, and I watered them often enough during the dry weather of late August through October to bring them along nicely. As a result both kinds of radishes yielded as well as they ever have. Note that ‘Red Meat’, a beautiful and tasty round winter radish that stores well, yielded about as well as the previous best year even though I planted the rows twice as far apart in 2015. As for turnips, despite planting the rows twice as far apart in 2015 I harvested twice the yield of the best year! In both these cases I think the generous amount of nitrogen available to them, aided by warm fall weather, helped them bulk up - and in the case of the turnips, sweeten up as well. They are the best-tasting turnips ever!

Of the leaf crops, years of experience has shown me that only arugula yields well when it’s direct-seeded in late summer, although in theory the other crops should work that way. I don’t know why direct-seeding doesn’t work well for these crops, but I do know that starting bok choy seeds in the basement and transplanting the seedlings in late summer produced a good crop in the past. So this year I direct-seeded the arugula and started seeds for the others in the basement. Actually, I started the seeds later than I should have. A mid-July start would have resulted in larger kale plants that would have withstood the late August and early September heat, as I mentioned in this post. But the bok choy responded extremely well to this method, besting the previous best yield by nearly a factor of 5! If I had known the bok choy would have done this well, I’d have planted much less of it. Bok choy does not store long in our makeshift root cellar and our refrigerator isn’t large enough for that much bok choy. Even giving a good portion of the crop away, we had to eat as much of the rest of it as fast as we could and leave the mustard greens, kale, and arugula in the garden. Because November and December were so much warmer than normal, we still had those to harvest until a few days ago. Both arugula and mustard greens would have had a best-ever yield if we hadn’t left them to freeze while we were eating up the bok choy. Next year I’ll grow more fall storage and kraut cabbage and less bok choy!

Lettuce and sunflowers

Although it may not seem like it, these two crops with very different growth habits and uses are both part of the aster plant family. I’ll discuss lettuce first.

Since lettuce bolts in heat and increasing day length and cannot survive our winters, I grow it the same way I grow bok choy, as a spring and fall crop. The spring crop is always started in flats and transplanted to the garden. We usually eat some of the heads before they mature so the yields are not as high as they would be otherwise, and this year it was some of the ‘Bronze Arrowhead’ plants that we chose to eat early, reducing its yield compared to the best year. Otherwise I think I’m at about the maximum spring yield I can get under our growing conditions. I liked ‘Kalura’, the romaine lettuce, very well. It’s the first romaine lettuce that has done well for me.

I find that lettuce won’t grow at all if I direct-seed it in August. Since I’d had some luck with lettuce that I started in the basement and planted out as transplants in 2008, I tried doing that in 2015. I probably started it about 2 weeks too late for maximum yield, but I was very pleased to get acceptable yields of the three lettuce on the spreadsheet, especially as warm and dry as it was in September and October, weather not to lettuce’s liking. In 2016 I’ll start the lettuce seeds in the basement in mid July and plant them out as transplants again.

The most important thing to know about the sunflower crop is that I got a crop. It’s not shown on the spreadsheet because I haven’t separated the seeds from the heads yet. But I was able to act ahead of the birds to get a yield for the first time ever! As I’ll discuss more in a future post, obtaining yields of oilseeds like sunflower is important if we’re to have a possibility of subsisting mostly on what I grow.

Beets, carrots, and parsnips

I plant all these as spring crops because, similarly to the lettuce and cabbage-family crops, they do not germinate and grow well, if at all, when direct-seeded into hot August soils and weather. In 2015 all started growing well in the favorable spring weather conditions, and I got a decent yield of beets considering that the rows were twice as far apart as during the year of the best yield. I’d have gotten a good yield of carrots as well, except that the local rabbits decided that carrot greens were what they wanted to eat in early summer. Although I have a short fence around the garden, it isn’t much of a barrier to rabbits, as their feeding on the carrot leaves proved. As a result the roots couldn’t bulk up, if they survived at all. I’ll have to think about what to do to reduce rabbit predation in 2016.

As for parsnips, I got them to germinate and grow well for the first time. But most of the leaves died by late summer and new leaves didn’t appear until October, when it cooled down. The first of the three rows that I harvested, in late November, produced only skinny roots. I’ve seen locally-grown parsnips so there is some way to grow them well here, but for as few parsnips as we use compared to beets and carrots, I’m happy to leave parsnips to the farmers in the future.

Squash-family crops

Of these I grew melons, cucumbers, zucchini, and butternut squash in 2015. Regarding melons, once again I failed to get any, not even from the hybrid melon that I tried. That’s it. I’m done with melons. Let the professionals grow them; I’m happy to support their successes.

Part of the reason for the reduced zucchini yield in 2015 compared to 2013 was excessive shading of the zucchini plants by the pole beans planted just to their south. There may have been another factor too, like having more plants in the same space in 2013. But no matter, I got zucchini to use in our summer salads.

I am not too concerned about the low yield of zucchini last year because we got more than enough cucumbers to make up for it. Besides setting a new yield record for the cucumber variety I show on the chart (growing the rows half as far apart in 2015 had a lot to do with that), I grew a second variety that yielded almost as well. We liked ‘Homemade Pickles’ a little better so that’s the one I’ll keep growing.

I’m not sure why the butternut squash did worse in 2015 than 2014. Fewer plants may have been part of the reason. The 2015 plants also seemed to give up and die earlier than they usually do, maybe from the excessive heat at the end of August lasting well into September.

Nightshade-family crops

In 2015 I grew potatoes, tomatoes, sweet and hot peppers, eggplants, tomatillos, and ground cherries from this family. Of these, I won’t grow the last two again: the plants sprawl too much, overwhelming the nearby plants that I cared more about, and we don’t use enough of either for me to want to bother with them again. I’m close to that point with eggplants as well, though with them it’s because I can’t grow the plants well enough to get much of a yield. I may try two to four eggplants once more this year, if I find space for them. They might do better with a boost from side-dressing, but as I explained, I didn’t end up doing that in 2015.

It’s easy to grow tomatoes here, as 2015 proved once again. I might have gotten higher yields from side-dressing, but even without it we get plenty of tomatoes. The yield from ‘Arkansas Traveler’ would have been higher if we hadn’t missed out on several tomatoes due to being out of town. ‘Black Prince’ had an intriguing taste but the tomatoes tended to rot before they were ripe. ‘Red Pear’ is a large Italian pear-shaped tomato that is fine for sauce but didn’t have a good enough taste to eat out of hand.

The extra nitrogen from the increased amount of cottonseed meal at planting time combined with nearly perfect weather from a pepper plant’s viewpoint resulted in an excellent pepper harvest. We seemed to have a never-ending pepper supply from July through October! All varieties had a best-ever year. ‘Jalapeno’ is bigger and heavier than ‘Serrano’, which explains part of the astounding yield increase for hot peppers. We ended up with 17 pounds of fresh jalapeno peppers, far more hot than we could use. We gave some away and I fermented some of them into hot pepper sauce, but we still have three gallon bags of hot peppers in our freezer. I won’t grow more than two hot pepper plants in 2016, if I grow them at all, and I won’t side-dress them because I don’t need them to be more productive. It might be interesting to see if side-dressing increases the sweet pepper yield even more. We’d find a use for extras.

As for potatoes, I had hoped that by following my mentor’s directions I’d have a better harvest in 2015. But potatoes may have suffered from the excessive rains in June more than most other vegetables. If I’d grown an early variety that matured in June, I’d probably not have harvested any potatoes. Because ‘Elba’ doesn’t mature till late July to early August, there was time for the soil to dry and the plants to set potatoes during the drier weather in July.

Sweet potatoes

These are members of the morning-glory family and like morning glories, they grow during the summer. As I explained in this post, two of the varieties I grew in 2015 suffered from vole predation. The surprise was that the third variety, ‘Hernandez’, had much less vole damage compared to the others and a much higher yield. All three were grown in the same bed. I don’t know why voles might prefer certain varieties, if they do, or if there was some other reason that the ‘Hernandez’ sweet potatoes were largely spared from vole predation (they were on one end of the bed). Since ‘Hernandez’ also proved to taste as good or better than the others, I’ll grow more of it in 2016.

Beans and peas

In 2015 I grew both shell and snow peas, which are spring-planted crops. Once again I planted them too soon and without pre-soaking or pre-sprouting them, and once again spotty germination resulted. But I still got a crop of each and did about as well as ever with the snow peas.

I grew a dry bush bean and two pole green beans in 2015. For some reason rabbits decided to munch on the bush bean plants but not the pole bean plants. By the time I noticed the rabbits’ work, the plants didn’t have enough time to set and mature a big crop. But I attempted to control predation anyway and got a small yield for my trouble, enough to save as seed for a future year’s crop.

Both of the two pole beans grew well and gave a good crop, considering how few and far apart the plants were compared to the best year. I hadn’t had a good crop of pole beans since 2009, so it was quite satisfying to have them again. Of the two varieties, Mike and I both preferred ‘Musica’, a flat romano type that remains tender to large sizes. We had more beans than we needed so I’ll reduce the pole bean area in 2016.

I grew two kinds of cowpeas. One, ‘Queen Anne’, is a bush type that produces white seeds with a black eye, what most folks in the US call black-eyed peas. I was alert enough to pick the patch multiple times and that resulted in a good yield. This crop might have yielded better with more rain or with watering, but I chose not to do the latter, instead concentrating municipal water on the greens and root crops during autumn. It also would have yielded better if I’d planted it at the beginning of June.

I also grew a pole type whose whole pod is eaten, similarly to green beans. It’s excellent stir-fried. The late planting and larger spacing compared to the best year has a lot to do with its yield being low in 2015, although we still had as many pods as we could use since it and the green pole beans were ready at the same time.

Popcorn

2015 was a critical year for the popcorn crop because the last year I had enough plants to save seeds from for replanting was 2012. Because corn seeds start losing their ability to germinate after 3 or 4 years, if I wanted to keep saving seeds, I needed to get a good yield in 2015. Plus we were about out of popcorn to eat.

Things started out well with the first two beds planted by mid June. Then the rains really set in, delaying the planting of the other two beds by another two to three weeks. The lack of cottonseed meal meant that I didn’t side-dress this high-demand, long-season crop.

Because the planting dates for each bed were different and the last two verged on too late to get much of a yield, I harvested and weighed from each bed separately. While I haven’t finished shelling out the popcorn from the last two planted beds, it was obvious from the sizes of the separated piles of ears that the yields from those beds will be much less than from the first two planted beds. And not only were the last two beds planted late, but the ears in those beds were developing during the very dry conditions of late August and September, yet I chose not to water the corn beds. Low yields for the two latest-planted beds were what I expected and what I obtained.

The low yields of the two best beds in 2015 compared to the 2009 planting can’t be explained on the basis of the planting dates. A number of factors may contribute to it. One factor might be the overall drier weather of July through September in 2015 versus 2009 and the fact that I didn’t water the 2015 crop when the rain stopped doing it for me. Another might be inbreeding depression. It’s recommended that corn seed not be saved unless you have a population of at least 100 to 200 plants, and more plants is much better. My plantings are at the low end of the recommended size. The result of saving seeds from too few plants is plants that grow progressively shorter, have fewer ears per plant, and mature later. While it seems to me that the plants are about the same size, have about the same number of ears, and mature at about the same time as they have in previous years, the ears seem to be shorter. Is that inbreeding depression or lack of enough moisture or fertility? I’ll find out the next time I grow popcorn. This year I had well over 200 plants and saved seeds from the best 100 ears for my seed crop. Hope that’s enough, but it might not be. Some year I may have to start over again with new seeds.

I have more to say on the implications of this year’s results, but that will have to wait for a future post.