Sunday, July 5, 2009
Someday I'll have a plot of land big enough for fruit trees and maize. In the meantime, I'm making do with my second story, western exposure deck.
This season I have two heirloom tomatoes (Hank and Black Plum), a sunberry, a ground cherry, green beans, snap peas, carrots and a salad mix. I'm also making an attempt to compost in the three black pots (an admitted long-shot). The minimum recommended size for compost piles is generally 3' x 3' x 3' but I'm gonna take a shot anyway. Maybe if I partially cover the tub in plastic it'll retain some heat during the winter...
I direct seeded the cold-weather species (carrots, peas, salad mix) at the beginning of June, following local recommendations. I started the warm weather fruits and beans in the greenhouse and transplanted them a few weeks later.
Shortly afterward I noticed that many of them were beginning to look pretty yellow/pale. Nitrogen deficiency was the first disorder to come to mind. Iron deficiency was also possible, but less likely since my plants did not retain green veins. Since plants are able to relocate some nutrients/micronutrients within their bodies (but not others), it can be an important clue if only the new leaves show symptoms, or only the old leaves. Overall, nitrogen deficiency is a common disorder and produces symptoms consistent with those observed.
Despite this, I was slow to believe nitrogen deficiency was the culprit since I had JUST planted the seedlings in new soil and because both legume species (pea and bean) are able to obtain nitrogen from the air through symbiotic rhizobia bacteria, which live in their roots. We had received a tremendous amount of rain the previous week, so it was also possible that the roots were not functioning well due to flood-induced oxygen deficiency. To test these hypothesis, I poked lots of holes in the soil in 2 containers to aerate them, and shredded clover roots (another legume growing in our lawn) into 2 other containers to inoculate them with the local microbes.
Unfortunately, the plants began to turn white over the next two days so I had to end my experiment and take more drastic action - by buying cheater-fertilizer. With plenty of nitrogen, the garden greened right up.