Tips for growing broccoli and cabbage in Oklahoma

Planting broccoli and cabbage can be challenging in Oklahoma—following these tips can help lead to a successful harvest.

Broccoli and cabbage are cool season crops that can be somewhat of a challenge to grow in Oklahoma. High temperatures in late spring, when plants are approaching harvest, can damage the developing heads. To avoid heat damage, plant as early as possible and select fast-maturing, heat-tolerant varieties. Experiment with planting dates and cultivars to see what works best in your corner of the state.

Select Early-Maturing Varieties

Broccoli and cabbage are typically grown from seedlings transplanted between late February and mid-March, as soon as the soil can be worked. Avoid planting delays in spring by covering beds with a tarp when rain is predicted. Consider mounding soil into elevated beds which drain and warm faster than flat ground. Both crops can also be grown in fall, which reduces problems with heat damage though establishing plants in late summer offers its own challenges.

For spring-planted crops, choose early-maturing, heat-tolerant varieties to ensure a good harvest. Find information regarding these traits on seed packets and in catalogue descriptions. Recommended cabbage varieties for Oklahoma include Charmant, Dynamo and Golden Acre Y.R. For red-leaved cabbage try Red Express or Red Acre. Early maturing broccoli varieties include Di Cicco, Flash, Emperor, Premium Crop and Packman.

For an even faster crop, consider planting a broccoli alternative. Raab, grown for its edible leaves and flower buds, matures in just 42 days. Gai Lan and its hybrids, commonly called broccolini, produce long tender stalks topped by small florets with a sweet, mild flavor. They mature in 45 to 60 days. Both can be grown from seedlings or directly sown into the garden.

Protect Plants from Common Pests

Several insect pests attack broccoli and cabbage plants at different stages of development. Cutworms are moth larvae that attack seedlings, cutting entire plants off at ground level by chewing through the stems. Protect plants with a cardboard collar made of a toilet paper tube extending one to two inches above and below the soil surface. Another control strategy interferes with cutworm behavior by placing a pencil or straw alongside the stem.

As seedlings mature, flea beetles and cabbage worms feed on the foliage. Cabbage worms include cabbage loopers, diamondback moths and imported cabbageworms. Cabbage worms and flea beetles can be managed with floating row covers, a lightweight, non-woven cloth that creates a barrier against pests but allows air, water and sunlight to reach plants. For a row cover to be effective, it must be firmly secured to the ground.

Fertilizing and Mulching Plants

Broccoli and cabbage are moderate to heavy feeders, but excess fertilizer can cause hollow stems. Amend soil with organic matter before planting to ensure a rich growing medium then mulch plants with dark compost after planting to warm soils during establishment.

Side dress with a nitrogen-rich fertilizer two to three weeks after planting. Side dressing is a method of fertilizing established plants without disturbing the root system. Apply the fertilizer in narrow furrows running along both sides of the planting row or in a circle around the base of each plant. You want to apply the fertilizer over the root zone of the plants while avoiding contact with plant stems. Gently rake fertilizer into the soil and water it in. Plants cannot take up nutrients from the soil without adequate moisture.

When the soil warms, mulch plants with straw, shredded leaves, or a similar material to retain soil moisture and regulate soil temperatures. Irrigate plants regularly to support faster growth. With a little cooperation from Mother Nature, you will enjoy a bountiful harvest in no time.