Collards, cabbage, spinach, and kale are among the most cold-hardy vegetables. You can see the frost on these leaves, which makes them sweeter.
Because a vegetable needs either warm or cool weather, crops sort themselves into two distinct categories: cool season (for spring and fall) and warm season (for summer). Planting in the proper season is the first step to a bountiful garden.
FOR SPRING AND FALL: Plant the hardy and semi-hardy vegetables below in early spring for spring harvests and again in late summer for fall harvests. These transplants should appear in your local garden centers at the right planting time. If you prefer a calendar, each state Extension service usually publishes a guide listing planting dates for all the vegetables. You can search the Web for your state’s calendar and contact information for your regional Extension agent.
Hardy vegetables tolerate hard frosts (usually 25 to 28 degrees F). They are good for spring and fall gardens. The hardiest–kale, spinach, and collards–can tolerate temperatures in the low 20s and high teens. All taste best when they mature in cool weather, so they are very well suited to late summer planting for fall harvests. Harvest extends into winter in the Southeast, Southwest, and Pacific Northwest. See the color coded USDA Frost Map for the median date of the first freeze throughout various regions of the US. This will give you an idea of just exactly how long your harvest season will last, because many of these hardy vegetables will continue in the garden for weeks after the first hard frost. It’s amazing. When you see this, you wonder “why doesn’t everyone plant a fall garden?”
- Brussels sprouts
- English peas
- Mustard greens
Lettuce and chard are among the veggies that will grow well in spring and fall, but need to be covered if temperatures dip much below freezing.
Semi-hardy vegetables tolerate light frosts (usually 29 to 32 degrees F) late into fall and through winter in mild climates. They are good for spring and fall gardens.
- Chinese cabbage
- Irish potatoes
- Lettuce and gourmet salad greens
- Swiss chard*
*Swiss chard and collards taste best in the cool of spring and fall, but will hang on during summer heat, too.
Squash is sensitive to cold, but loves warm summer weather.
FOR SUMMER: Plant these in high spring, after the threat of frost is past. These tender vegetables need warm weather (65 to 90 degrees F) to grow and are killed by frost. They are for summer gardens only (except in the nearly frost-free climates of zones 9b and 10).
- Southern peas
- Summer squash
- Sweet potatoes