Thinking small can be as challenging as thinking big. And planning a successful vegetable garden in limited space requires an especially disciplined approach.
Although the pleasures of a small garden are prodigious, the challenges are not trivial. Where to put those six tomato plants when there is room for only three? Should zucchini or cucumber be included this year? Melons are marvelous, but how will their sprawling vines fit into a confined patch?
In the small garden, the contest always is to pare down, and then pare down again.
Add to this the notion of keeping varieties in constant rotation from season to season, and the entire endeavor is further complicated.
Rotation is the musical-chairs practice of moving different varieties around each season, avoiding planting the same crop in the same place year after year. The principle behind the practice is to prevent contaminating new plants with the diseases of old ones.
Equally important, rotating varieties enables soil to recover and replenish the nutrients devoured by a previous crop. Corn and leafy greens _ broccoli, for instance _ take large amounts of nitrogen from the soil, while others, such as legumes, help balance nutrient levels.
But rotating crops within a small area is not easy. A single tomato plant, for example, extends its roots in a radius of five feet or more. This could represent fully a third of the available area in a small plot. How does one set out new tomato plants in a spot not used last season by at least a part of a tomato vine?
Be aware that rotating varieties is suggested, not required. With a little extra care, it is possible to grow healthy plants in pretty much the same location year after year. True, some problems may surface eventually without rotation, but the pleasure and availability of the harvest in the meantime are worth it.
First, replenish soil nutrients regularly. Compost, compost, compost. Add organic matter. An organic mulch _ covering soil surfaces at all times with something growing or something decaying _ is important. The time to amend soil is now, at the end of the gardening season and well before planting begins in spring.
Besides compost, other additives should include animal manures (avoid dog and cat feces because they carry parasites that can infect humans), organic fertilizers that are slow to release, granular kelp, leaf mold and composted yard waste (check your local recycling center for information on this). Mulches range from the easily available _ leaves, preferably shredded _ to the expensive _ bags from garden centers.
Next, lay out your small plot on paper or in your head, rotating anything you can. Plant peppers where last year you had broccoli; put the eggplant where the cucumbers grew; basil and lettuce can trade places. Or plan a circular rotation, moving each crop up to the next row and bringing the top one around to the bottom.
It's helpful to know which varieties share maladies: Fusarium and verticillium affect tomatoes as well as squashes. If either disease appears and kills squashes or tomatoes, it lingers in the soil that surrounded the main root clump of either vegetable. Thus, if a tomato plant suffered from one of these diseases last year, don't plant a squash in the same spot; farther away, toward the outer rim of where the tomato roots might have stretched, the squash plant would be safe enough.
The best course of action against these and other diseases is to go for resistant varieties. This is especially valid for gardens where space or availability of sun is sufficiently limited that rotation or periodic relocation of the vegetable bed is not possible.
Selecting varieties carefully is the first line of defense. The second is to make hard choices each year, something not unfamiliar to the gardener with limited space.
Like so much of gardening, dealing with nature is always a balancing act. Not everything is going to fit every year, but one of the pleasures of gardening is trying different combinations with each new season.