Spring, when everything is emerging from dormancy and starting to grow again, is often the season that comes to mind when considering planting vegetables or fruit-bearing cultivars. But summer and fall cannot be discounted. Many vegetables, particularly those that are grown for their leaves and roots, are cool-season plants that hit maturity after the warmest weather of the year has passed. Some can even withstand hard frosts. Fall, rather than spring, is preferable for planting fruit trees.
Varieties like Oakleaf and black-seeded Simpson can be planted in the summer months. Seedlings can tolerate a light frosts. The first harvest can occur within 40 to 50 days and lasts for four to six weeks. As with any other vegetable, calculating regional planting time is crucial to avoid hard frost damage. Lettuce grows best in moist soil, so adequate water must be given during early fall, when dry period can occur.
Radishes are a cool-season root vegetable that can be planted in late summer in more northern climates. They are one of the fastest growers, reaching maturity within about 30 days. Cool, moist weather promotes growth. Winter varieties taste better if exposed to the first frost. Crop rotation in successive years is essential to mitigate diseases.
Onion seeds of short to intermediate day-length varieties can be planted in late summer and are hardy enough to withstand frosts. They reach maturity within 130 to 150 days. Texas A&M University's Horticulture Department says onions get a good growing boost if gardeners band phosphorous 2 to 3 inches below seeds when they are planted. Nitrogen-based fertilizer can also be used to encourage optimal growth.
Healthy, 1-year-old apple trees with good root systems should be planted later in the fall, after any lengthy dry periods have occurred and the wet weather has returned. Roots can be soaked for 24 hours if they have begun to dry. Soil should be tamped down around roots, and the tree's graft should be at least 2 inches above the soil line. One-year-old trees take two or more years to produce fruit after planting, the North Carolina State University Cooperative Extension Service says.
Kale, prized for its flavorful and colorful leaves, can be planted throughout the summer and is frost hardy. Like radishes, they taste best after they've been exposed to frost. In the United Kingdom, which features growing conditions similar to zones in the Southern United States, it can be harvested from autumn to mid-spring. In northern climates, this primitive cabbage can be covered with straw during the winter and harvested through the spring.