How to Grow Broccoli in Oklahoma
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Learning how to grow broccoli in Oklahoma means understanding your local climate, soil conditions, and the timing of planting to avoid the hottest parts of the year, when broccoli tends to bolt or lose flavor. It’s simple to do, even for beginning gardeners.
Broccoli is a cool-season vegetable that thrives in areas with moderate temperatures, making it a suitable crop for Oklahoma’s spring and fall gardening seasons. With proper planning, timing, and care, gardeners across Oklahoma can enjoy a bountiful harvest of this nutritious and versatile vegetable. Broccoli is packed with vitamins, minerals, fiber, and antioxidants, making it a great addition to any home garden.
Check out this month by month garden planting guide for more tips on when to grow what in Oklahoma.
Understanding Oklahoma’s Climate
Oklahoma lies in USDA hardiness zones 6 through 8, with hot summers, cold winters, and a wide range of microclimates influenced by elevation and geography. Spring and fall provide the best windows for growing broccoli since the plant prefers temperatures between 60°F and 75°F.
Temperatures above 80°F can cause broccoli to bolt or flower prematurely, which results in a bitter taste and smaller heads. Oklahoma’s variable weather patterns can be challenging, but with a little flexibility and good timing, it’s very possible to have a successful broccoli crop. The only thing you have to do is make sure it doesn’t get too hot. It can even take a little frost.
Choosing the Right Broccoli Variety
Selecting a heat-tolerant, fast-maturing broccoli variety is important in Oklahoma’s climate. Some popular varieties that do well include:
- Green Magic: A fast-maturing hybrid with good heat tolerance, ideal for spring or early fall.
- Packman: Produces large heads quickly and is suitable for early harvest.
- Waltham 29: An heirloom variety that does well in cooler weather and produces side shoots.
- Belstar: A reliable hybrid known for its uniform heads and disease resistance.
- Calabrese: A traditional variety that grows well in fall gardens.
For spring planting, choose varieties that mature quickly to avoid the heat of late spring. For fall planting, choose varieties that can tolerate light frost and maturing in cooler weather.
When to Plant Broccoli in Oklahoma
Timing is crucial to grow broccoli in Oklahoma. You want to give it enough time to mature while staying within its preferred temperature range.
For spring broccoli, start seeds indoors about 6–8 weeks before the last expected frost date. In much of Oklahoma, the last frost typically falls between March 15 and April 10. This means seeds should be started indoors in January or February. Transplant seedlings outdoors about 2–4 weeks before the last frost, once they are about 4–6 weeks old and hardened off. This usually falls between February and early April.
For fall broccoli, direct sow seeds in mid to late July, or start seeds indoors in late June and transplant in early to mid-August. Fall crops tend to be more reliable in Oklahoma due to fewer pest problems and more favorable temperatures as the season cools. I have not had a lot of luck planting broccoli direct seeding, but we also have a lot of rabbits and they will eat seedlings up to a certain stage.
✔Here’s a link to a great vegetable garden planner you can print right out and use at home! So cute!
Starting Broccoli from Seed
To start broccoli seeds indoors, use seed trays or small pots filled with quality seed-starting mix. Plant seeds ¼ to ½ inch deep and keep the soil moist but not soggy. Provide plenty of light, either through a bright south-facing window or under grow lights for 12 to 16 hours per day. Seedlings will emerge in 5 to 10 days. A heat mat is a great helper for broccoli seeds, they like a little warmth.
Once the seedlings develop their second set of true leaves, thin them to one per cell or container. Before transplanting outside, gradually acclimate the seedlings by placing them outdoors for a few hours each day over the course of a week. This is called hardening off.
Soil Preparation for Broccoli
Broccoli prefers well-drained, fertile soil with a pH between 6.0 and 7.0. Begin by choosing a sunny location that receives at least 6 hours of sunlight per day. Prepare the soil by removing weeds, loosening it with a garden fork or tiller, and incorporating organic matter such as compost or aged manure.
Amend the soil with a balanced fertilizer or apply a slow-release organic fertilizer before planting. If your soil is heavy clay (which is common in many parts of Oklahoma), improve drainage and texture by adding compost, aged manure, and sand. A soil test can be very helpful for determining pH and nutrient levels, allowing you to make adjustments as needed.
Transplanting Seedlings into the Garden
When transplanting broccoli into your garden, space the plants 18 to 24 inches apart in rows that are 24 to 36 inches apart. Water the soil before and after transplanting to help settle the roots and reduce transplant shock. We do like to plant them a little closer together, but we like to do that with everything. Sometimes it works, sometimes there is regret.
It’s helpful to add mulch around the plants to conserve moisture, suppress weeds, and moderate soil temperature. Straw, shredded leaves, or grass clippings make excellent organic mulches. We like straw the best.
Watering and Fertilizing Broccoli
Consistent watering is key to growing healthy broccoli. Aim to provide 1 inch of water per week, including rainfall. Water at the base of the plants to keep foliage dry and reduce the risk of disease.
Broccoli is a heavy feeder, so side-dress with compost or balanced fertilizer about 3 to 4 weeks after transplanting. Avoid over-fertilizing with nitrogen alone, as this can lead to large leafy plants with small heads. A balanced fertilizer like 10-10-10 or an organic blend with nitrogen, phosphorus, and potassium will support strong growth and good head formation.
Managing Pests and Diseases
Broccoli can attract several common garden pests in Oklahoma, especially during the spring season. These include:
- Cabbage loopers and cabbage worms: Green caterpillars that chew holes in leaves. Handpick or use Bacillus thuringiensis (Bt), a natural and safe biological control. (We hate cabbage looper worms, blech. We have them bad here)
- Aphids: Small sap-sucking insects that cluster on new growth. Blast them off with water or spray with insecticidal soap.
- Flea beetles: Tiny jumping insects that leave small holes in leaves. Use row covers early in the season or neem oil for control.
- Cutworms: Larvae that chew through stems near the soil line. Prevent by placing cardboard collars around seedlings and keeping the area weed-free.
Diseases such as downy mildew, black rot, and clubroot can affect broccoli, especially in wet conditions. To reduce disease risk:
- Rotate crops annually and avoid planting broccoli or other brassicas in the same spot for 3 years.
- Avoid overhead watering and water early in the day to allow foliage to dry.
- Keep garden beds weed-free and provide good airflow between plants.
Supporting Head Development
The edible part of broccoli is the central head, and timely harvesting is important. Once the main head reaches 4 to 7 inches across and the buds are tight and compact, it’s time to harvest. Don’t wait for the buds to open into yellow flowers, as that signals the broccoli is past its prime.
Cut the central head with a sharp knife, leaving several inches of the stalk and the side leaves intact. Many varieties will then produce smaller side shoots that you can continue harvesting for several weeks. I love the cut and come again produce!
Harvesting Broccoli in Oklahoma
In spring, broccoli will be ready for harvest about 55 to 80 days after transplanting, depending on the variety and weather conditions. In fall gardens, broccoli can be harvested through the first few light frosts, which can actually improve flavor.
Broccoli is frost-tolerant and can handle light freezes down to the mid-20s°F. However, be sure to harvest before a hard freeze is expected. In warmer areas of Oklahoma, a well-timed fall planting can yield fresh broccoli into December.
Storing and Using Fresh Broccoli
After harvesting, rinse the broccoli and pat dry. Store it in the refrigerator in a plastic or reusable produce bag with a paper towel to absorb moisture. Fresh broccoli lasts about 5 to 7 days in the fridge.
You can use broccoli raw in salads or with dips, steam it for a simple side dish, roast it with garlic and olive oil, or add it to soups, stir-fries, casseroles, and pasta dishes. Broccoli can also be blanched and frozen for long-term storage.
Saving Seeds from Broccoli
If you grow open-pollinated or heirloom broccoli varieties and want to save seeds, you’ll need to allow some plants to bolt and produce seed pods. This is best done in a dedicated seed-saving area, away from hybrid or other brassica plants to avoid cross-pollination. Allow the seed pods to dry on the plant, then collect and store them in a cool, dry place.
Seed saving can be challenging in Oklahoma due to the long season needed for full seed maturity, so most home gardeners prefer to purchase fresh seeds each year from trusted sources.
How to grow broccoli in containers
If you don’t have garden space, you can still grow broccoli in large containers on a patio or balcony. Use a container that’s at least 12 to 18 inches wide and deep, with good drainage. Fill it with high-quality potting mix, and feed regularly with organic fertilizer. Water frequently, especially during warm, dry weather. Container-grown broccoli needs the same timing considerations as garden-grown plants and can be moved into shade during hot spells to reduce stress.
How to Grow Cole Crops
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