People frequently ask me about the correct time to plant different vegetables and fruits. Planting times are a subject that confused me when I began gardening. The guidance offered by seed companies and gardening magazines is somewhat vague because the writers want the information to appeal to everyone.
The instruction that bewildered me the most was “Sow seed as soon as the ground can be worked in spring.” I can work the ground in my garden in South Carolina nearly every day of the year. If the ground does freeze, it often thaws by early afternoon, and within a week’s time from the cold night, we will usually have a day in the sixties. Garden writers, I have found, often live in colder climates where they have many months in which they cannot garden because the ground is covered with ice and snow. They are inside, writing about gardening and trying not to think about us fortunate Southerners outside, on a lovely January day, gardening.
To figure out planting dates, know frost dates. In the Midlands of SC, our first fall frost usually occurs around November 1, although frost can happen a couple of weeks before or after that date. Our last spring frost usually occurs around April 1, give or take a couple of weeks. To figure out planting dates, decide whether you will sow the seed directly in the garden or whether you will first sow it inside and transplant it outdoors later. For example, it is best to start tomato plants from seed inside the house under grow lights so they will be big enough to transplant outside when the danger of frost has passed. The package says to start them about six weeks before the last frost, which means I usually start my tomato seeds inside around Valentine’s Day. I also start peppers, eggplant, and broccoli inside under lights. I sow green beans directly in the garden, and so I do not sow them until April. I sow almost all other vegetables directly in the garden.
In January, sow cabbage and broccoli indoors. In February, or six to eight weeks before the last spring frost, sow broccoli, cabbage, spinach and other leafy greens, bulb onions, tomatoes, peppers, basil, & eggplant indoors. Start sweet potato slips indoors. Sow leafy greens, carrots, parsnips, beets, and English peas outdoors. Plant Irish potatoes outside. In March, continue sowing the crops as described above. Transplant cool-weather crops outside when they are large enough.
In April, sow leafy greens outdoors, but know the heat we often have in late May will cause them to bolt and to become bitter. However, we might have a cool spring, and so planting the greens later is worth the risk. Transplant broccoli and cabbage into the garden, but it is too late to start them from seed because hot weather will arrive before they mature. Plant green beans, lima beans, crowder peas, corn, okra, squash, and cucumber seeds outside.
In mid-April, or sooner if you are brave, set out tomato, pepper, and eggplant transplants in the garden. Just remember that in 2007 the temperature dropped to about 24°F on the morning of April 7. That spring I had not set out my tomatoes yet, but many gardeners lost their crop. I have planted tomatoes unadvisedly early, as an experiment, and covered them with plastic, but nothing besides a heated greenhouse can protect them from that sort of cold. Although some plants can survive a light frost, tomatoes cannot. I wait until mid-April to set out mine; just because the big-box stores have transplants for sale does not mean it's time to set them out in the garden.
Throughout the summer, make successive plantings of beans, squash, and cucumbers. Start some more tomato seeds indoors to set out in August for a fall crop. In August, plant cool-season crops like beets, carrots, leafy greens, broccoli, and cabbage in the garden for a fall and winter crop.
Draw your crop plan on a piece of paper so you can put new crops in the spaces vacated by spent crops, and make your garden its most productive. Purchase your seeds for the spring, because it is time to get to work.