The first sweet corn of the season, hot and buttered, is already in my sights as I shuffle through the seed packets, noting which crops I can sow now and hurry along for an early harvest. Traditionally, corn is not one of them. Usually direct-sown in the ground, it will grow fine in cool soil as low as 50 degrees. But here’s the problem: It won’t germinate happily until the soil is at least 65 degrees or better.
The solution is unorthodox, but it works. In our garden we just start the seeds indoors in luxurious 80-degree potting mix. We use soil blocks, made with a soil-block maker, which compresses the mix into sturdy little cubes. But you could also use Cow Pots, which are made from composted cow manure. These biodegradable pots — best suited to short-term use — break down quickly so that roots can strike out around the plant without delay, and their fertility content is an added plus. We plant four seeds in each soil block or pot.
The seedlings will emerge almost instantly, within four days at most, and it is critically important to put them into the ground the minute they pop up, so growth is not checked. So you’ll want to have your garden ready to receive them, with the sweet corn bed amended, cultivated and weeded. Soil temperatures reach the 50s in Washington by the end of April.
Corn is a hungry feeder and will be happiest if you amend the soil well with compost and/or manure the fall before. But no worries. You can do it now if the manure is well decomposed — not like the stuff in the cheeky French cartoon in the Paris newspaper Le Monde, in which a farmer astride a horse drops seeds behind him into each manure deposit the horse lets fall, and corn plants sprout instantly as he goes.
The idea is not so far-fetched. Farmers have been known to lay down cowpats, mounded with soil, as a base into which to drop a hill of corn seed. Native Americans similarly buried a fish head underneath each cluster of seeds. These customs, perhaps, explain the somewhat confusing use of the word “hill” to mean a cluster of planted seeds, whether mounded or not. When you plant a hill of bean seeds they might be in a mound but more likely just a cluster or a small circle. A hill of potatoes might be in an actual mound, the better to protect the tubers from sunlight, which turns them a toxic green.
Our hills of corn consist of those four seedlings sown in each soil block, thinned to the strongest three. (With any biodegradable pots, make sure they are filled to the tops with soil and the edges buried a bit below soil level, so they will not wick moisture away from the seedlings.) We plant the little groups 18 inches apart, down the center of a 30-inch-wide bed.
Just one bed? One is often told to set out corn plants in blocks, to aid in their pollination by wind. But pollination is assured if they are clumped together in hills. It’s also easier to weed or cultivate them with this wide spacing, while the summer warms up, bringing us that much closer to corn heaven.
Herbaceous peony plants should be staked now before they produce too much foliage. Hoop frames — sometimes called grow-through supports — provide the best and least conspicuous means of support. Heavily petaled double varieties of peony are the most prone for flopping and breaking. Single and semi-double varieties are less likely to be a problem. Tree peonies and semi-woody “intersectional” peonies don’t require staking.
— Adrian Higgins
Damrosch’s latest book is “The Four Season Farm Gardener’s Cookbook.”