Q. I have heard you and others emphasize crop rotation as an integral part of successful organic gardening. But as an urban gardener I have limited space, and I don't have many options left for my sun-loving plants. What is my best bet for limiting disease problems? Am I better off just skipping some crops some years? Growing in containers? It would be sad to have to do without something essential like tomatoes... Thanks,
- ---Ruchika in Somerville, MA
These wilts are one reason I'm always stressing the importance of putting crushed eggshells in the planting hole to avoid blossom end rot in tomatoes. It takes a few years for these great sources of natural calcium to completely decompose, so if you find heirloom eggshells while digging a hole that's intended to receive tomatoes, you know to plant something else in that spot.
Now, when space is scarce and you just can't go the recommended three to four years between planting tomatoes in the same spot, you have several options. One is to grow your tomatoes in big containers every couple of years, following the guidelines in our 'GROWING TOMATOES IN CONTAINERS' article. You can even re-use those containers for tomatoes the following year if you change out all of their soil.
You could also join a community garden near your home, work or school to expand your potential growing areas. Or ask a friend or neighbor if you can install some love apples in their garden. And if all else fails, excavate the soil from the raised bed you need for tomato growing, completely replace the old soil with a mixture of compost, rich black screened topsoil and some high-quality chemical-free soil free mix and plant away.
Now, some other plants are technically susceptible to these wilts, and you'll often see articles with long lists of them, but I've never experienced such a thing personally; tomatoes seem to be the real drama queens here.
Let's put root crops in second place for rotation importance. I've been noticing that when I grow garlic in the same bed as the previous season, I lose more heads to neck rot than when I rotate my plantings. It makes sense that crops that produce their bounty underground might be more at risk of soil-borne disease than plants that just have roots down there. So now I put markers in the soil when I harvest my garlic in June to insure that I don't use the same bed when I plant my new crop in September.
A frequently repeated piece of advice on this subject is to rotate roots, fruits and leaves. So an ideal plan for a plot would be say, potatoes (the root) one year, peppers (the fruit) the next year, then salad greens as the leaves the third year. But many of the 'non-roots, non-fruits'—things like lettuce, spinach, and broccoli—are cool-season crops that are typically grown before and after the fruits of summer, often in the same physical space. So you must also consider the delicate balance between succession and rotation in your plans.
This makes a good argument for compulsive record keeping. Draw a chart of your garden beds, photocopy it and date every copy by year—or by year AND season if you're a succession planter. Then doodle out your options for the coming year on a couple of blank sheets during the off-season. As added insurance, leave plant markers in the ground or install new ones indicating what was there when you cleaned things out at the end of the last season.
If your brain has not yet begun to explode under the weight of all these options, you can also add into the equation the pests that overwinter underneath the plants they attack. Cucumber beetles and squash bugs, for instance, are much easier to control if the plants they ravage are positioned in locations far away from the ones that were attacked by their ancestors the previous year.
The ideal goal is to move everything around every season; a different crop in each spot every year, ideally for at least three full seasons. Can anyone do this perfectly? Probably not; I know that I certainly can't. So do the best you can—and practice the ethic of constant improvement. The more years you garden in the same location, the more you should pay attention to rotation.
But don't you dare neglect the other essentials of successful organic growing: Build raised beds; enrich your soil with organic matter; mulch with compost or shredded leaves to prevent weeds and retain moisture; water deeply and infrequently; and provide lots of room between plants for airflow, and sturdy support for vining crops. All of these are as important as rotation, if not more so.
Yes, The Sainted Gardener will keep excellent records, follow a dedicated plan of rotations and allow each bed to go fallow or be enriched by a cover crop of green manure every seven years. Meanwhile, the other 98% of us will stumble along, trying to pay attention and generally having lots of fun in addition to the occasional unwanted adventure.
You'll never be sorry that you took the time to think things through before planting—especially with tomatoes and root crops—but rotation is just one piece of the puzzle. Think of it as an odds-improver, and not an impediment to outdoor enjoyment.