When To Plant Fall Broccoli In Zone 7

If you’re planning your autumn garden in zone 7, knowing exactly when to plant fall broccoli is the key to a successful harvest. Getting the timing right ensures your plants mature during cool weather, which is essential for forming those tight, flavorful heads. This guide will walk you through the perfect schedule and simple steps for a bountiful crop.

Fall broccoli is often easier to grow than spring broccoli. The cooler autumn temperatures prevent the plant from bolting (flowering) too quickly, which can happen in spring’s unpredictable warmth. You’ll be rewarded with sweeter, more tender heads that can keep producing side shoots after the main head is cut.

For most of zone 7, the ideal time to plant fall broccoli is from late July through mid-August. This target window is crucial. Planting too early exposes young plants to summer’s peak heat, causing stress. Planting to late means the broccoli won’t mature before your first hard freeze.

A more precise method is to count backwards from your average first fall frost date. You can find this date through your local cooperative extension office. Most broccoli varieties need 55 to 85 days to mature from transplanting.

Step 1: Find your average first fall frost date (e.g., October 25th).
Step 2: Choose your broccoli variety and note its “days to maturity” (e.g., 70 days).
Step 3: Add about 10 days for seed starting and transplant shock. So, 70 + 10 = 80 days.
Step 4: Count back 80 days from October 25th. This lands you around August 6th.

This calculation gives you your optimal transplant date. Since you’ll start seeds indoors, you need to back up even further.

Starting Your Broccoli Seeds Indoors

Broccoli seeds germinate best in cooler soil, so starting them indoors in summer is the way to go. Aim to sow your seeds about 5 to 7 weeks before your planned transplant date. For that August 6th transplant, you’d start seeds in late June.

Fill seed trays or small pots with a sterile seed-starting mix.
Plant two seeds per cell, about ¼ inch deep.
Water gently and keep the soil consistently moist but not soggy.
Place the trays in a bright location; a south-facing window or under grow lights is ideal.
Seeds should sprout in 5-10 days. Once they have their first set of true leaves, thin to the strongest seedling per cell.

Keep your seedlings well-watered and consider using a diluted half-strength liquid fertilizer every two weeks to keep them growing strong.

Preparing the Garden and Transplanting

While your seedlings grow, prepare their future home. Choose a spot that gets full sun (at least 6 hours daily). Broccoli prefers rich, well-draining soil with a slightly acidic to neutral pH.

Work in 2 to 3 inches of compost or well-rotted manure into the top 6 inches of soil.
You can also mix in a balanced organic fertilizer according to package directions.
Ensure the bed has good drainage to prevent root rot.

Transplant your seedlings on a cloudy afternoon or in the evening to reduce shock. Harden them off for a week first by gradually exposing them to outdoor conditions.

Space plants 18 to 24 inches apart in rows that are 24 to 36 inches apart. They need room to grow.
Dig a hole slightly deeper than the root ball.
Place the seedling in the hole, burying the stem up to the first set of true leaves. This encourages a sturdier plant.
Water deeply immediately after planting.

Caring for Your Fall Broccoli Crop

Consistent care is what turns good broccoli into great broccoli. The main challenges in fall are initial heat and later, pests.

Watering and Mulching

Broccoli needs about 1 to 1.5 inches of water per week. Use a soaker hose or drip irrigation to keep water off the leaves, which helps prevent disease. A thick layer of straw or shredded leaves mulch is a game-changer. It keeps the soil cool and moist during late summer heat and suppresses weeds.

Fertilizing for Growth

Feed your broccoli three times during its life cycle. First, at transplanting with the prepared soil. Second, about 3 weeks after transplanting with a nitrogen-rich fertilizer like fish emulsion. Third, when the small heads begin to form to support their development.

Pest and Disease Watch

Cabbage worms, aphids, and flea beetles are common pests. Check the undersides of leaves regularly.

For caterpillars, use Bacillus thuringiensis (Bt), an organic bacterial spray.
Blast aphids off with a strong spray of water or use insecticidal soap.
Floating row covers installed right after transplanting can exclude many pests entirely.

Harvesting Your Autumn Broccoli

Your broccoli is ready when the central head is tight, firm, and the individual florets are still small and densely packed. If you see the florets starting to separate or show yellow flowers, harvest immediately—it’s beginning to bolt.

Use a sharp knife and cut the main stem at a slant, about 5 to 8 inches below the head.
This clean cut helps prevent rot and encourages side shoot production.
After the main head is harvested, many varieties will produce smaller side shoots for several more weeks. Keep watering and you’ll keep harvesting!

Recommended Varieties for Zone 7 Fall Gardens

Choosing the right variety can make your job easier. Look for types known for good heat tolerance and reliable performance.

Calabrese: A classic, reliable heirloom with excellent flavor.
Green Magic: Known for its heat tolerance and smooth, domed heads.
Arcadia: A great choice for fall; it’s cold-tolerant and produces many side shoots.
Belstar: Hybrid known for consistent performance and good disease resistance.

FAQs for Fall Broccoli in Zone 7

Can I direct seed broccoli in the fall in zone 7?

You can, but it’s trickier. The intense summer sun can dry out tiny seedlings, and pest pressure is higher. Starting indoors gives you a more reliable head start and stronger plants.

What if I miss the ideal planting window?

If it’s late August or early September, opt for a fast-maturing variety (around 50-60 days). You can also try sowing seeds directly and thin them later, but be prepared to protect young plants from pests.

How do I protect broccoli from an early frost?

Broccoli can handle a light frost, which can even improve its flavor. For a predicted hard freeze (below 28°F), cover your plants with a frost blanket, old bedsheets, or a cold frame overnight. This can extend your harvest by weeks.

Why are my broccoli heads small and loose?

This is called “buttoning” and is usually caused by stress. The most common culprits in fall are transplanting seedlings that are to old or exposing them to a prolonged period of cold weather when they are very young. Nutrient deficiency can also be a factor.

Growing fall broccoli in zone 7 is a rewarding endevor that extends your fresh harvest into the cooler months. By hitting that late-summer planting window, giving your plants a strong start indoors, and providing consistent care, you’ll set your garden up for success. There’s nothing quite like the taste of homegrown broccoli from your own autumn garden.