Carrots for the fall harvest
Root crops such as carrots and beets can be planted through early September.
By now, early-summer crops like cucumbers and summer squash have mostly fizzled out, leaving space in the garden. Instead of letting weeds grow, consider planting fall vegetables.
Carrots, rutabagas, beets and turnips are tasty and nutritious root crops planted from late July through early September. These crops perform best in a loose, deep, loamy or sandy soil with plenty of organic matter. Root vegetables will grow in heavy clay soils, but their roots will be smaller and misshapen.
When preparing space for fall crops take time to clean up the planting area. Remove withered plants from the earlier crop and pull out roots. Plants that were generally healthy can be added to your compost pile, but discard any plants with diseases or insects. Also remove any rotten fruit, stems or leaves and pull all weeds from the planting area. Cultivate the cleared soil with a rototiller or spading fork to loosen it and break up clods. You want a smooth soil bed free of stones and other impediments.
If you followed soil test recommendations for fertilizing and pH adjustment in the spring, then you may only need a light application of nitrogen fertilizer such as calcium nitrate or blood meal. If you don’t know the nutrient status of your soil, a soil test from Clemson Extension will provide you with prescription-like recommendations of how to optimize the soil for these crops. For new planting areas that haven’t been soil tested, mix in 3 pounds of 5-10-10 or similar fertilizer per 100 square feet before planting.
Fall-season root vegetables can be seeded directly into the garden. The seeds are very small, and it is easiest to scatter them in narrow bands. To get a good stand you should sow the seeds rather thickly, but this means you’ll need to thin the seedlings later. Banded rows should be at least a foot apart for carrots, beets and turnips and up to 3 feet for rutabagas.
When the seedlings are 2 inches tall, thin carrots and beets until there are 2 to 3 inches between plants. Turnips and rutabagas should be thinned 4 to 6 inches apart. Thinning seedlings can seem wasteful, but it’s absolutely necessary to get sizeable roots. You can make use of all but the carrot thinnings by washing and adding them to a salad or stir-fry.
Root crops are moderate feeders and will need to be side-dressed with 1 pound of calcium nitrate per 100 feet of row once the plants are about 4 inches tall. Keep fertilizer 3 inches away from the seedlings to avoid burning their young roots. A liquid fertilizer applied at 1- to 2-week intervals will also work, but avoid over-fertilization which will hinder root development.
Soil should stay uniformly moist for the best roots. Irrigate during periods of dry weather, especially as the roots are developing, by moistening the soil to 6 inches deep.
Weeds may be the biggest challenge for your fall crop. Weeds grow rapidly during the summer and will quickly overtake seedlings if left unchecked. Keep an eye out for these pests and pluck them away at first sight.
Edible roots will begin developing 6 to 8 weeks after planting. You can harvest tender roots as early as you like, but oversized roots may become tough and woody. Carrots are typically harvested when their roots begin to show above the soil; beets when they are 1 to 2 inches in diameter; turnips when they are 2 to 3 inches in diameter; and rutabagas when softball sized. All of these crops will store for months in plastic bags in the refrigerator, allowing you to enjoy homegrown produce all winter long.
S. Cory Tanner is an area horticulture agent and Master Gardener coordinator for Clemson Extension based in Greenville County. Contact him at shannt@clemson.edu.