Joseph Masabni, Assistant Professor and Extension Horticulturist, The Texas A&M University System
Collards are one of the most nutritious vegetables. They are low in calories and high in protein, vitamins, and minerals. Although they are a member of the cabbage family, collards do not form heads. They are grown for their leaves.
Collards tolerate more heat and cold than most other vegetables grown in Texas. They are easy to grow, productive, and well suited to either large or small gardens. Collards grow best in cool weather and need as much sunlight as possible.
Collards need a deep soil that is well drained and well prepared. The roots of a collard plant easily reach depths of 2 feet of more. Dig the soil as deep as possible or at least 10 inches. This will loosen the soil so the small feeder roots can grow more easily.
Before planting, remove rocks and large sticks from the soil; then spade it over to cover the plant material on the soil surface. Allow time for the material to begin rotting. If the soil is mostly clay or light sand, add organic matter. A 4-inch layer of compost is enough. Spread the compost over the planting area before digging.
Just before planting, scatter a complete garden fertilizer such as 10-10-10 over the area you will plant. Use 2 or 3 pounds for each 100 square feet, or about 1 cup for each 10 feet of row. Use a rake to mix the fertilizer 3 to 4 inches into the soil. Work the soil into ridges that are 6 to 8 inches high and at least 36 inches apart (Fig. 1). This brings the fertilizer under the row, where the plants can reach it easily. The ridges also allow water to drain away from the plant roots.
Collard varieties suitable for growing in Texas include Blue Max, Champion, Flash, Georgia LS, Georgia Southern, Top Bunch, and Vates.
Collards can be started from transplants or from seeds sown directly in the garden. Transplants usually are used for the spring crop. They add 4 to 5 weeks to the growing season because they can be grown indoors before the weather is warm enough to plant the seeds outside. Collard seeds sprout when the soil temperature reaches 45 degrees F.
Move the transplants into the garden as soon as the soil can be worked in the spring; in most of Texas, this is in February or March. Set the plants in the soil at about the same depth as they were grown indoors. Space them 18 to 24 inches apart in the row (Fig. 2). Water the plants after transplanting.
When planting seeds, make a shallow furrow about ½ inch deep down the center of the bed. Scatter the seeds lightly in the furrow. With a little practice, you can easily scatter the seeds by using your fingers to lightly tap the edge of the open seed packet. One teaspoon of seed will plant about 30 feet of row. Cover the seeds with about ¼ inch of loose soil or compost; then sprinkle them with water. The plants should come up in 6 to 12 days. However, the colder the soil is, the more slowly the seeds will sprout. For a fall crop, plant the seeds in the garden about 80 days before frost, which corresponds to August or September in most areas of Texas. Seed them heavily and then thin them.
Care during the season
After the plants have sprouted, let them grow until they get about 4 to 6 inches tall or become crowded in the row. Then thin the plants gradually until about 18 inches remain between them. Crowding causes the leaves to be smaller and less green. The young plants can be either transplanted to another spot or used as greens (Fig. 3).
Scatter 1 cup of garden fertilizer beside the plants for each 30 feet of row, about 1 tablespoon per plant. This is called side-dressing. Mix the fertilizer lightly with the soil, and water. The plants may need to be sidedressed again in 4 to 6 weeks if they become pale and there is no sign that insects caused the change. When the plants are thinned to their final spacing or if they become pale green, add a little more fertilizer. Collards need plenty of nitrogen to develop their dark green leaf color.
Water the plants well each week if it does not rain.
Keep the garden free of weeds because they rob the plants of water and nutrients. Pull the weeds or hoe them carefully to prevent damage to the collard plant’s roots.
Many insecticides are available at garden centers for homeowner use. Sevin® is a synthetic insecticide; organic options include Bt-based insecticides and sulfur. Sulfur also has fungicidal properties and helps control many diseases.
Before using a pesticide, read the label and always follow cautions, warnings, and directions.
Collards are subject to some diseases. If the plants have spots on the leaves, you may need to use a fungicide. Check the plants daily, and treat them with an approved fungicide if diseases appear. Neem oil, sulfur, and other fungicides are available for use. Always follow the label directions.
Collards can be harvested in two ways. For small plants that need thinning, cut the entire plant about 4 inches above the ground (Fig. 4). Sometimes they will sprout back from the side of the stem. Usually, only the lower leaves of collards are harvested. This allows the plant to continue growing and producing more leaves. In mild regions, such as South Texas and coastal areas, collards will produce all winter. Collards can stand temperatures of 20 degrees F or less in some cases. They taste sweeter after a light frost.
To prevent the loss of nutrients, do not cook collards in too much water. Your county Extension agent can provide more information on cooking and serving collards.
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View this publication in Spanish: Cómo cultivar col verde
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