Maryland Grows

One of the most common questions asked by novice vegetable and herb gardeners is “How many?” That is, how many of each plant to put in, so that the harvest will be enough to make dinner but not so much that you’re frantically trying to find homes for a major surplus. When you plan an ornamental border, there are design guidelines that talk about groups and masses and specimen plants, but food gardens (although they can be beautiful) are not planted with aesthetics primarily in mind. So how to make these choices?

You can find plenty of guides online for, say, planning a garden for a family of four. These tend to assume that your garden is large and that you want to supply all or most of your needs from it. Which is great if that’s your goal, but I don’t find that many of the busy urban and suburban gardeners I talk to mean to skip the supermarket produce section entirely. The online guides will also measure the planting in feet of row; if you grow in the square footage of raised beds, you’ll have to do some recalculation. Growing in these kinds of high volumes probably also requires food preservation, whether by freezing, canning, or some other method.

Most of us find the answer to “How many?” through trial and error, and frankly you probably can’t avoid that entirely. You’ll err on the side of not enough for some plants, and too much for others, and will serve some salads featuring a handful of lettuce or one small cucumber, or get to know your neighbors when you have tons of extra tomatoes. But there are ways to plan.

The Herb Garden

I said last month that you will only ever need one culinary sage plant, and that’s pretty much true, but if you happen to end up with more, it’s not a tragedy. Extra herb plants can be thought of as ornamental pollinator attractors, especially the slow-growing Mediterranean perennials like sage, thyme, rosemary, lavender, and other strong-smelling woody plants. Some of the low-growing herbs make great ground covers. Since rosemary isn’t reliably hardy in our climate (mostly because of rollercoaster freezes and thaws in the late winter), you may want to plant a couple of plants or a new one every year, in case an older one dies. The other herbs are quite tough.

You do need to watch out for aggressive spreading with the mints, oregano, lemon balm and other related herbs, but this is more an issue of planting in the right place to begin with and keeping up with maintenance, rather than choosing a number of plants. There will be more plants if you let it happen!

Annual and biennial herbs like basil and parsley take a little more planning, but if you end up with only a few plants you should still have enough for seasoning, and most of the leafy herbs can be made into some kind of pesto if you have quite a lot. Many herbs can be frozen or dried, as well. Try to pick your herbs before they bolt into flower. In general, though, this is not the part of your garden to become anxious about.

The Vegetable Garden

Don’t be anxious about this garden either! But it does take a little more planning. The general rule here is to think about how much of each vegetable you use for a meal, and how many meals you think you’ll want to use it for before you get sick of it, and then find out a bit about how the vegetable grows. For example:

• Say you really like beets, and during the season they’re producing you want to serve them once a week.
• Your family usually eats three medium-sized beets per meal.
• Beets sown in early April will be ready for harvest around 60 days later (early June), and will continue to be harvestable until temperatures get super-hot in mid-July. (There can be a second crop in the fall, sown in late summer, but never mind that now.)
• Three beets per week times six weeks is eighteen beets. Make it twenty for ease of calculation and loss to pests or errors. There’s one beet per plant.
• Beet seeds are sown about 1-2 inches apart and then thinned later on to about three inches apart. So you’ll need to plant many more seeds than the eventual harvest. (The thinnings can be used in salads.)
• You’ll need about five feet of row for these beets, or the equivalent in square footage. (Think of the space rather than the number of seeds, because of the thinning factor. Nearly all seed packets will have plenty for your needs.)
• Now the more complicated bit: Beets can wait in the ground to be harvested after they’ve reached a good size, but it’s better to not let them sit for a long time. You don’t want to have to harvest too many at once or you’ll have to serve beets at every meal. Succession planting is the way to go here. Plant a foot or two of row per week over the course of three weeks, starting when the soil temperature reaches about 50 degrees F.
• If you are planning to can or pickle some beets, you can be much more generous in your planting, and plant them all at once so the harvest comes in together.

Ideally, you’re doing this sort of calculation for every crop, though I can tell you from experience you won’t have time to figure it all out, and as you can see above, it requires a fair amount of knowledge and research about the crop. At the very least, keep some records so you know that (completely random example here) five shishito pepper plants are just too many, but two are not enough. Over time, you will develop a plan that works for you, but in the meanwhile, there’s nothing wrong with making a few mistakes. Start small and add more next time, and you’ll be less likely to end up with too many vegetables to handle.

Of course, you also have to remember that these plants have to fit into your available space! Sometimes this is the hardest part of planning a garden…

A few nuggets of gleaned experience:

• The crops I have overplanted the most often are lettuce and radishes. I think this is the enthusiasm of early spring getting the better of reason. Succession planting is very much your friend here.
• On the other hand, I have underplanted peas quite a few times. This is partly because of low germination, and also because they take a while to get going. Plant more than you think you need, and if you end up not harvesting the late flush in the heat of June, so be it.
• Summer squash is notorious for overproduction as well as for crop failure. Either you end up with far more squash than you need, or you end up with none because the plants die from pests or disease. Succession planting is once again the solution. Put in a few more seeds each week, as needed, from the time it gets warm enough in May until around mid-July.
• Heirloom tomato plants may produce only a few tomatoes per plant. Or they may be as generous as hybrid plants, or more so; it depends on which varieties suit your growing conditions best. In general you should plan for hybrids to be more productive (maybe 20 large tomatoes per plant, rather than 5 for the lower-producing heirlooms; medium tomatoes are usually a bit more productive than beefsteaks). You should also plan for cherry tomatoes to overwhelm you with delicious profusion. One plant may be sufficient.

• Corn is the only common vegetable for which you have to think about wind pollination needs. You can’t just plant a couple of corn plants and expect to get ears. Think blocks of about four feet square, rather than long rows.
• Sweet potatoes and winter squash, if cured and stored correctly, will last quite a while after harvest, so if you’re going to go nuts with something, these are good choices. Potatoes, onions and garlic also last in storage.

I wish you the exact number of plants you need! And I sympathize if you end up with too few or too many. Spring is coming soon – plan your garden now!

By Erica Smith, Montgomery County Master Gardener. Read more posts by Erica.