If you’re planning your Missouri vegetable garden, knowing when to plant broccoli is key to a successful harvest. For Missouri’s climate, timing is everything to beat the heat and ensure crisp, tasty heads.
Broccoli is a cool-season crop that thrives in Missouri’s spring and fall. Planting at the right time avoids the stress of summer heat, which can cause plants to bolt and produce flowers instead of the tight heads we want. Let’s break down the best schedule for your region.
When To Plant Broccoli In Missouri
Missouri spans USDA Hardiness Zones 5b to 7a, meaning planting dates shift by about 2-3 weeks from north to south. The goal is to time planting so broccoli matures during cool weather.
Spring Planting Dates
For a spring crop, broccoli is typically started indoors from seed and then transplanted outside. This gives it a head start before warm arrives.
- Northern Missouri (Zones 5b-6a): Start seeds indoors 6-8 weeks before your last average spring frost date. Transplant seedlings into the garden 2-4 weeks before that last frost date, when soil is workable. This is usually late March to mid-April.
- Central Missouri (Zone 6b): Start seeds indoors in early to mid-February. Transplant from mid-March to early April.
- Southern Missouri (Zone 7a): You can start seeds indoors in late January. Transplant from early to late March.
A good rule of thumb is to get transplants in the ground so they mature before daytime temperatures consistently exceed 75°F. If a late frost threatens after planting, be prepared to cover young plants with row cover or cloches.
Fall Planting Dates
Many gardeners find fall broccoli even more succesful in Missouri. The cooling temperatures of autumn improve flavor and head development. For fall harvest, you’ll calculate backwards from your first average fall frost date.
- Start seeds indoors in mid to late summer, about 10-12 weeks before your first fall frost.
- Transplant seedlings into the garden about 6-8 weeks before that first frost. This is often during the hot days of August, so providing afternoon shade for young transplants is crucial.
Example dates for transplanting fall broccoli:
Northern MO: Early to mid-August
Central MO: Mid to late August
Southern MO: Late August to early September
Direct Sowing Seeds Outdoors
You can also sow broccoli seeds directly in the garden. For spring, wait until soil temperature is at least 40°F. For fall, sow seeds about 3-4 weeks earlier than the transplant dates listed above. Direct sowing requires consistant moisture for germination.
Choosing the Right Broccoli Varieties
Selecting varieties suited to Missouri’s sometimes erratic springs and falls will increase your success. Look for heat-tolerant and fast-maturing types.
- Green Goliath / Premium Crop: Reliable, heat-tolerant classics good for both spring and fall.
- Calabrese: An heirloom type known for its excellent flavor.
- Packman: A fast-maturing hybrid (about 55 days) that’s great for beating the heat.
- Belstar: Performs well in both cool and warm conditions, with good side-shoot production.
- Waltham 29: A cold-tolerant variety excellent for fall harvesting, as flavor improves after a light frost.
Preparing Your Garden Soil
Broccoli needs fertile, well-draining soil with a pH between 6.0 and 7.0. A few weeks before planting, work in 2-3 inches of compost or well-rotted manure. Adding a balanced, slow-release organic fertilizer at planting time will provide steady nutrients. Broccoli is a heavy feeder, so don’t skip this step.
Step-by-Step Planting Guide
- Harden Off Transplants: If you started seeds indoors, acclimate seedlings to outdoor conditions over 7-10 days by gradually increasing their time outside.
- Spacing: Plant transplants 18-24 inches apart in rows spaced 2-3 feet apart. This gives plants room to grow and ensures good air circulation.
- Planting Depth: Set transplants slightly deeper than they were in their pots, up to their first set of true leaves. This encourages a strong stem.
- Water Thoroughly: Water immediately after planting to settle the soil around the roots.
- Mulch: Apply 2-3 inches of organic mulch (straw, shredded leaves) to conserve moisture, suppress weeds, and keep soil cool.
Caring for Your Broccoli Plants
Consistent care is simple but vital. Broccoli needs about 1-1.5 inches of water per week. Drip irrigation or soaker hoses are ideal to keep foliage dry and prevent disease. Side-dress plants with a nitrogen-rich fertilizer (like blood meal or a balanced veggie fertilizer) about 3-4 weeks after transplanting to support heavy growth.
Watch for common pests like cabbage worms and aphids. Check the undersides of leaves regularly. You can use floating row covers as a barrier or apply organic controls like Bt (Bacillus thuringiensis) for caterpillars. Good garden hygiene helps prevent issues.
Harvesting Your Broccoli
Harvest is the rewarding part! Heads are ready when the central head is tight, firm, and the individual florets are still small and densely packed. Cut the main stem at a slant about 5-6 inches below the head. Many varieties will then produce smaller side shoots for several weeks after the main head is cut, extending your harvest.
For fall broccoli, you can often harvest even after a few light frosts, which can make the flavor sweeter. Just get them before a hard freeze.
Common Challenges in Missouri’s Climate
The biggest challenge is temperature fluctuation. A sudden hot spell in spring can cause “bolting,” where the plant flowers prematurely. Choosing heat-tolerant varieties and sticking to the early planting schedule is your best defense. In fall, the challenge is getting plants established in summer heat. Use shade cloth if needed and be diligent about watering.
Wet springs can promote fungal diseases. Ensure proper spacing for air flow and avoid overhead watering to keep leaves dry. Rotating your broccoli’s location each year helps prevent soil-borne diseases from building up.
FAQs: Planting Broccoli in Missouri
Can I plant broccoli in July in Missouri?
Yes, but only for a fall harvest. Mid to late July is the time to start seeds indoors for transplanting in August. Direct seeding outdoors in July is very difficult due to heat and dry soil.
What is the latest you can plant broccoli for fall?
Aim to have transplants in the ground by early September in central Missouri, and late August in the north. After that, there may not be enough cool growing days for heads to form properly before a hard freeze.
Does broccoli grow well in Missouri?
It grows very well, especially as a fall crop. The key is precise timing around the states variable weather. Spring crops can be trickier but are very doable with planning.
Can broccoli survive a frost in Missouri?
Yes. Broccoli is frost-tolerant and can handle light frosts (down to about 28°F) quite well. In fact, a light frost can improve the flavor. Protect transplants if a hard freeze is expected while they are young.
How long does broccoli take to grow?
From transplant, most varieties take 55 to 85 days to produce a main head. Check the “days to maturity” on your seed packet, and count from your transplant date, not from seeding.
By following these guidelines tailored to Missouri’s unique climate, you can enjoy two productive broccoli seasons each year. Paying attention to your local frost dates and being prepared to protect young plants from extremes will lead to a bountiful harvest of this nutritious garden favorite.