When To Plant Broccoli In Ohio

If you’re planning your Ohio vegetable garden, knowing when to plant broccoli in Ohio is the first step to a great harvest. Getting the timing right is crucial because broccoli loves cool weather, and Ohio’s springs and falls are perfect for it.

Plant too early, and a late frost might damage your seedlings. Plant too late, and summer heat can cause the heads to bolt, or flower, before they’re ready to eat. This guide will walk you through the optimal schedule for both spring and fall planting, so you can enjoy this nutritious crop from your own backyard.

Ohio’s climate is split between USDA Hardiness Zones 5 and 6, which means our springs can be unpredictable. For a spring crop, the general rule is to get broccoli transplants into the ground 2-4 weeks before your last average spring frost date. For a fall crop, timing is based on working backwards from your first average fall frost.

Here’s a quick reference for major Ohio areas:

Northern Ohio (Zone 5): Last spring frost around May 15. Plant transplants outdoors between April 20 and May 6.
Central Ohio (Zone 6a): Last spring frost around May 5. Plant transplants outdoors between April 10 and April 25.
Southern Ohio (Zone 6b): Last spring frost around April 25. Plant transplants outdoors between April 1 and April 15.

Spring Planting Schedule Step-by-Step

Spring planting is the most common method. You’ll start seeds indoors to get a jump on the season.

Start Seeds Indoors: Begin 6-8 weeks before your planned outdoor planting date. For Central Ohio, that means sowing seeds around late February to early March. Use a quality seed-starting mix.
Grow Strong Seedlings: Provide plenty of light—a sunny south window or grow lights for 14-16 hours a day. Keep the soil moist but not soggy.
Harden Off Plants: About 10-14 days before transplanting, gradually expose your seedlings to outdoor conditions. Start with a few hours of shade and protected from wind, increasing time and sun exposure each day.
Transplant to the Garden: Once seedlings have 4-6 true leaves and are hardened off, plant them in your garden. Space them 18-24 inches apart in rows 2-3 feet apart.

Fall Planting Schedule Step-by-Step

Fall-grown broccoli often produces larger, sweeter heads because it matures in cooler weather. The key is to calculate your planting date so the heads mature after summer heat but before a hard freeze.

Calculate Your Date: Find your first average fall frost date. Count backwards 85-100 days (check your seed packet for the ‘days to maturity’). This is your seed-starting date. For a late-October frost, start seeds in mid-to-late July.
Start Seeds: In summer, you can start seeds indoors in a cool spot or directly in a shaded nursery bed outdoors. The soil can dry out fast, so monitor moisture closely.
Transplant in Late Summer: Transplant seedlings to the garden about 4-6 weeks after sowing, when they are sturdy. This is typically in August. Provide shade cloth for the first week if it’s very hot.

Choosing the Right Broccoli Varieties for Ohio

Selecting varieties suited to our climate improves your success. Look for ones with good heat or cold tolerance.

For Spring: Choose fast-maturing varieties (50-70 days) to beat the heat. Good options include ‘Green Goliath’, ‘Calabrese’, and ‘Packman’.
For Fall: You can use slower-maturing types (70-100 days) as they grow into cool weather. Try ‘Belstar’, ‘Arcadia’ (excellent frost tolerance), or ‘Waltham 29’.
Side-Shoot Types: Varieties like ‘Broccoli Raab’ or ‘De Cicco’ produce many small florets after the main head is cut, extending your harvest.

Preparing Your Garden Soil

Broccoli is a heavy feeder. It thrives in fertile, well-draining soil with a pH between 6.0 and 7.0.

Work in 2-4 inches of compost or well-rotted manure a few weeks before planting.
You can also mix in a balanced organic fertilizer according to package directions.
Ensure the planting site gets full sun—at least 6 hours of direct sunlight daily.

Caring for Your Broccoli Plants

Consistent care prevents problems and leads to big, tight heads.

Watering: Provide 1-1.5 inches of water per week. Water at the base of the plant to keep leaves dry and prevent disease. Drip irrigation or a soaker hose is ideal.
Mulching: Apply 2-3 inches of straw or shredded leaves around plants. This conserves moisture, suppresses weeds, and keeps soil cool.
Fertilizing: Side-dress plants with a nitrogen-rich fertilizer (like blood meal or a balanced veggie food) about 3 weeks after transplanting.
Pest Watch: Common pests include cabbage worms, aphids, and flea beetles. Check undersides of leaves regularly. Use floating row covers as a barrier or apply organic controls like Bt (Bacillus thuringiensis) for worms.

Harvesting Your Broccoli at the Right Time

Harvest is the best part! Timing is everything for flavor and texture.

Cut the central head when the florets are tight, firm, and deep green, before any yellow flowers start to open. The head should be 4-8 inches across.
Use a sharp knife and make a slanted cut about 5-6 inches down the stem.
After the main head is harvested, many varieties will continue to produce smaller side shoots for several weeks. Keep harvesting these to encourage more production.

Common Problems and Solutions

Even with good timing, issues can arise. Here’s how to handle them:

Bolting: If the plant flowers prematurely, it’s usually due to stress from temperature swings or lack of water. Stick to the planting schedule and water consistently. Once a plant bolts, the head becomes bitter; pull it and try again next season.
Loose, Bumpy Heads: This can be from too much heat or inconsistent watering. Mulch heavily and maintain even soil moisture.
Yellowing Leaves: Could indicate a nitrogen deficiency. Side-dress with a nitrogen-rich fertilizer.
No Head Forming: If plants look healthy but no head forms, it might be due to extreme heat, damage to the roots during transplant, or using a poor-quality seed.

FAQ: Ohio Broccoli Planting

Can I plant broccoli directly in the garden in Ohio?
Yes, but it’s trickier. For spring, you can sow seeds outdoors 2-3 weeks before the last frost, but growth will be slow in the cool soil. For fall, direct sowing in July is more reliable because the soil is warm.

What is the latest I can plant broccoli in Ohio?
For a fall crop, you can succession plant quick-maturing varieties (around 50 days) up until about 10-12 weeks before your first hard frost. This might give you a late harvest of smaller heads or side shoots.

Can broccoli survive a frost in Ohio?
Yes! Broccoli is quite frost-tolerant. Mature plants can handle temperatures down to about 25°F. A light frost can actually improve the flavor, making it sweeter. Use a row cover for extra protection during a hard freeze warning.

Should I start with seeds or transplants?
Transplants are recommended for spring to get ahead of the heat. For fall, either method works, but starting seeds indoors in July protects them from the hottest weather.

Why did my broccoli only produce small heads?
Small heads are often caused by overcrowding, inadequate sunlight, poor soil fertility, or stress from heat/drought. Ensure you give your plants enough space, sun, food, and water for best results.