Now is the time to plant cool season crops

By Kathy Hatfield
Gardening Columnist

Back to Gardening Articles List

It's not too early to start planting those early season crops, and peas should be the first crop to get into the ground. Otherwise, you'll get a poor harvest if peas are flowering when the weather turns warm.

Before you plant the pea seeds, it's a good idea to put up some type of support, such as wire fencing or a trellis, on which they can climb. Plant the seeds on either side of the support, about 2 to 3 inches apart. Rows should be spaced 3 to 4 feet apart to allow ample room for harvesting the peas. Soil needs to be well drained, but not exceptionally rich, since peas are legumes and can use atmospheric nitrogen.

Peas will germinate at temperatures between 40 and 75 degrees, but will germinate more quickly at higher temperatures. Using row covers can help warm the soil early in the spring, but should be taken off when daytime temperatures reach 60 degrees or above. Once they have germinated, peas like cool temperatures--55 to 70 degrees is ideal. Peas can survive temperatures in the 20s, and still produce undamaged peas.

Salad greens such as lettuce and spinach will flourish in cooler growing conditions. Unlike peas, most salad greens do best if they are grown in soil amended with good quality, manure-rich compost. Both spinach and lettuce will germinate in soil temperatures of 35 to 75 degrees, with fewer seeds germinating at higher temperatures. It will take one to two weeks before you'll see the tiny plants popping out of the soil. But once up and growing, 60-degree weather is fine for both. The fibrous roots of lettuce and spinach do not grow very deep into the soil, so watering is critical. Keeping plants mulched will help conserve precious water.

Root crops like carrots, beets and radishes will bolt, or go to seed, if they are planted too late and have to develop in hot weather. Most of their energy will be put into developing seeds, rather than forming large, healthy roots. Also included in this group is Swiss chard. Though not a root crop, it is the same species as beets; therefore, its growing requirements are similar. Swiss chard will continue to grow all summer, but can be started early for a jump on fresh garden vegetables. It is especially important for root crops to have loose, well-drained soil. Without it, carrots become abnormally shaped, short and stubby, or otherwise deformed. Radishes grown in clay are tough and misshapen. Soil does not need to be particularly high in nitrogen. Too much nitrogen will produce carrots with small feeder roots, and most people would probably rather not have hairy carrots.

It's a good idea to mulch root crops. Mulch helps hold in moisture, keeps weeds down and protects the tops of root crops. When the top of a carrot root is exposed to sunlight, it not only produces chlorophyll and turns green, but it also produces bitter-tasting chemicals that make it inedible. Exposed beet roots become tough and may crack.

It's important to keep your young plants thinned and weeded. Competition from neighboring plants will result in reduced yields. Many gardeners find weeding therapeutic, but often don't enjoy thinning because they are destroying the very plants they sowed. Luckily there are some other options available. Some people like to mix the seed with sand so that the seeds are spread a bit thinner as they are sown. Another alternative is to buy seed tape. Seeds are spaced at an ideal distance apart and imbedded in a biodegradable tape, so that all you do is lay down the tape and cover it with soil for a perfectly spaced row of vegetables. The disadvantages are that seeds purchased this way are more expensive and not all varieties are available in seed tape. With a plant like beets, it's hard to avoid thinning them. Each beet "seed" is actually a small fruit containing many seeds, so that they will most likely need thinning.

The cole crops, also known as the cabbage family, include broccoli, brussels sprouts, cauliflower, cabbage and kohlrabi. They're best started indoors and transplanted into the garden. Unless you start them quite early, so that they are a good size in time for spring planting, these are best grown as a fall crop. Once established, the coles prefer temperatures in the 60s, and many can withstand temperatures below freezing.

With most of these cool season crops, high temperatures and long days cause them to bolt. Their flowering stem lengthens and flower and seed production follows. Once this happens, their usefulness as a garden vegetable is over.