Several kinds of vegetables, mostly those that can be used for salads and greens, are hardy and can be planted outdoors before danger of frost is over. This includes cabbage, lettuce, broccoli, brussels sprouts, cauliflower, collard, cress, kale, korirabi, mustard, onion, English pea, radish, rhubarb, rutabage, salsify, spinach, and turnip.
But do not work clay soils when they are wet and sticky. Even regular walking over wet clay soil will compact it, reducing the size of channels for water and air movement. The weight presses the soil down and the soil particles themselves do not get any smaller.
They become hard, compact and cloddy and it may take a long time to restore them to a good condition.
Squeeze some soil in your hand. If it forms a compact ball and does not crumble readily when released, it is too wet to work. This goes for vegetables gardens, for lawns and for planting trees and shrubs. Wait until the soil dries out.
Clay soils can be greatly improved by mixing organic matter, lime and fertilizer with them. Peat, compost, partially decayed leaves and barnyard manure do a good job. To determine if your soil is too acid and needs lime, have it tested. Phone your county extension agent for instructions on how to take the samples and where to send them.
Radishes should be ready to harvest in 24 to 28 days after they areplanted. Cherry Belle, Champion, Comet, Sparkler, Stop Lite and Icicle are good varieties. Radishes grow best in cool spring weather.
Leaf lettuce is one of the best crops for the early spring garden; head lettuce may not mature in time before hot weather. Bibb lettuce produces a loose head and tender leaves with fine flavour. The entire plant will be ready to harvest about 64 days after seeds are planted. Buttercrunch is a good variety. Salad bowl, Burpee's Greenheart, Green Ice, Black-seeded Simpson and Ruby are excellent varieties.
Spinach is a high quality, nutritious vegetable, but it is much better as a fall crop because it cannot take hot summer weather. New Zealand and Malabar spinach and Tampala (Fordhook), as well as Swiss Chard, stand heat and produce well during the summer months.
Unlike tomatoes and peppers, cabbage can be planted outdoors about four weeks before the last frost date. Your best bet is to buy small plants at a garden centre.
Broccoli is closely related to cabbage and can be treated in the same way with early planting. Like cabbage, broccoli will not form heads until about six weeks after planting.
Collard is closely related to kale but has flat rather than curled leaves. Vates is a good variety. Harvest when the leaves are about 12 inches long.
Be sure to thin the vegetables after the seeds germinate. If the plants are allowed to grow crowded together in the row, there will be a smaller yield and a poor-quality product