A traditional farm planting schedule is useful for home gardening as well. It can be helpful for urban gardeners to understand the traditional seasonal planting schedule that farmers adhere to as a way to understand nature. Crops planted in spring and fall thrive when temperatures are 70 degrees F or lower. Crops planted in summer need temperatures between 70 and 90 degrees F to grow well. The USDA planting zone map gives the exact temperature range for your location.
On farms where winter snow is heavy, the earliest outside planting time may be February. Peas, cabbage, carrots, cauliflower, chard, lettuce, onions, spinach and turnips can all be planted by seed or transplants. Rotate crop locations each year to prevent disease and insect problems. Vegetables can be mulched as soon as they begin to grow.
Sweet corn is planted mid-March to April for summer harvest, along with lima, wax and pole beans. Beets, broccoli, radish and rhubarb are also vegetables to plant in spring. Okra, peppers and pumpkins can be put in the ground by the end of April. Large-scale farms often produce compost from animal manure and use it all year round. Home gardeners can reproduce this process with a compost bin in the yard.
Tomatoes will not grow well until soil warms up to 50 to 55 degrees F. Farms that produce a large crop of tomatoes to eat, sell and preserve will have prepared the tomato plot with compost before planting time and reduce the application of compost when blossoms set. Other vegetables planted in summer include watermelon, cantaloupe, squash and peppers. Summer is a good time to feed vegetables with a side-dressing of compost fertilizer.
After harvesting early maturing vegetables such as salad greens, radishes, peas and spinach, fall crops can be planted. Many vegetables have 50- to 70-day growing seasons and come to maturity by the time winter sets in. Root crops such as beets, carrots, turnips and kohlrabi do well in a mid-summer planting. Bush snap beans mature in 45 to 60 days and can tolerate a light frost when temperatures dip to 30 degrees F. Kale planted in mid-summer continues to produce leaves to harvest throughout the winter. Its taste is said to improve after a frost.
Fall and Winter
Even in the coldest USDA planting zones, winter crops may be grown on farms in greenhouses, small cold frames or plastic tunnel "hoop houses." In mild winter weather zones, cool season vegetables can be planted year round. Vegetables that do well in winter include lettuces, radish, broccoli, kale, Brussels sprouts, leeks, beets and turnips. Protect plants from severe drops in temperature with thick mulch so roots do not freeze. Straw, newspaper and compost are good mulch materials.