When To Plant Broccoli In Maryland

Getting your broccoli planting time right is the key to a great harvest in Maryland. Knowing exactly when to plant broccoli in Maryland makes all the difference between tight, delicious heads and disappointing results.

Our state’s unique climate, with its distinct seasons and variable springs, requires a specific schedule. This guide gives you the clear, practical steps you need for success, from seed to harvest.

For most of Maryland, broccoli is a cool-season crop grown in two main windows: spring and fall. The fall planting is often easier and more productive for beginners.

Spring Planting: The goal is to get transplants into the garden early, so they mature before summer heat arrives. Start seeds indoors 6-8 weeks before your last expected spring frost. For central Maryland, that’s usually around late February to mid-March. Transplant your sturdy seedlings outdoors 2-4 weeks befor the last frost date, when the soil is workable. This can be as early as late March or early April.

Fall Planting: This is the secret to fantastic broccoli. You start seeds in the heat of summer for a harvest in the cool of autumn. Calculate by counting backwards from your first fall frost date. Start seeds indoors or in a shaded seedbed about 10-12 weeks before that first frost. For most areas, this means sowing seeds in mid-to-late July. Transplant seedlings into the garden in late August or early September.

Understanding Maryland’s Climate Zones

Maryland spans USDA Hardiness Zones 5b through 8a. This affects your precise timing:

Western Maryland (Zones 5b-6b): Has a shorter spring and earlier fall frosts. Lean toward the later end of spring planting and the earlier end of fall seeding.
Central MD/Piedmont (Zones 6b-7a): This includes Baltimore and Frederick areas. Follow the standard timing outlined above.
Southern MD & Eastern Shore (Zones 7a-7b): Longer growing season. You can plant spring transplants a bit earlier in spring and have a longer fall window. Succession planting in fall works well here.

Step-by-Step: Starting Broccoli from Seed

Starting your own plants gives you the best variety choice and control.

Choose Your Seeds: Pick varieties suited for Maryland. For spring, choose fast-maturing types (like ‘Green Goliath’). For fall, any variety works, but heat-tolerant starters (like ‘Packman’) are good for summer sowing.
Sow Indoors: Fill cells with seed starting mix. Plant 2-3 seeds per cell, ¼ inch deep. Water gently.
Provide Light & Warmth: Seeds need warmth (70-75°F) to germinate. Once sprouted, they need plenty of light—a sunny south window or grow lights for 14-16 hours a day to prevent leggyness.
Thin & Harden Off: Thin to the strongest seedling per cell. One week before transplanting, begin hardening off: place plants outdoors in a shaded, sheltered spot for a few hours daily, gradually increasing their time outside.

Preparing Your Garden Bed

Broccoli thrives in fertile, well-drained soil with a pH between 6.0 and 7.0.

Location: Pick a spot that gets full sun (at least 6 hours).
Soil Test: A UMD extension soil test is best. It tells you exactly what your soil needs.
Amend the Soil: Work in 2-3 inches of compost or well-rotted manure a few weeks before planting. This improves drainage and fertility.
Fertilize: Mix in a balanced organic fertilizer at planting time according to package rates.

Transplanting Seedlings Outdoors

Transplant on a cloudy day or in the late afternoon to reduce shock. Space plants 18-24 inches apart in rows 2-3 feet apart. Dig a hole slightly deeper than the root ball. Set the plant in so the lowest leaves are just above the soil surface. Water deeply immediately after planting.

Caring for Your Broccoli Plants

Consistent care prevents problems and boosts yield.

Watering: Provide 1-1.5 inches of water per week. Water at the base, not the leaves, to prevent disease. Drip irrigation or soaker hoses are ideal.
Mulching: Apply 2-3 inches of straw or shredded leaves around plants. This conserves moisture, suppresses weeds, and keeps soil cool.
Feeding: Side-dress plants with a high-nitrogen fertilizer (like blood meal or a balanced organic blend) about 3 weeks after transplanting.
Pest Patrol: Watch for cabbage worms and aphids. Check undersides of leaves. Use floating row covers as a barrier, or handpick pests. Bacillus thuringiensis (Bt) is an effective organic spray for caterpillers.

The Fall Planting Advantage

Fall-grown broccoli often produces larger, sweeter heads. The cooling temperatures are ideal. Pest pressure from cabbage worms is usually lower in the fall. You also get a longer harvest period, as mature plants hold better in cool weather. If an early frost threatens, you can cover your plants with a row cover to extend the season.

Harvesting Your Broccoli

Harvest when the central head is tight, firm, and dark green, before the individual flower buds start to swell and yellow. Use a sharp knife to cut the main stem at a slant, about 5-6 inches below the head. After the main head is harvested, most varieties will produce smaller side shoots for several weeks. Keep picking these to encourage more production.

Common Problems and Solutions

Bolting (Flowering Prematurely): Caused by stress from temperature swings or transplanting too-old seedlings. Stick to the planting windows and use young, vigorous plants.
Loose, Bitter Heads: Usually from too much heat or not enough water. Ensure consistent moisture and use mulch.
Small Heads: Can be from poor soil fertility, overcrowding, or inconsistent watering.
Yellowing Leaves: Could indicate a nitrogen deficiency. A side-dressing of fertilizer can help green them up.

Recommended Varieties for Maryland

Some reliable choices include:
‘Calabrese’ (heirloom, great for fall), ‘Packman’ (fast, heat-tolerant), ‘Belstar’ (reliable hybrid), ‘Waltham 29’ (excellent cold tolerance for late fall), and ‘Purple Sprouting’ (for early spring harvests of side shoots).

FAQ

Can I plant broccoli directly in the garden in Maryland?
Yes, but timing is trickier. For a fall crop, you can direct sow seeds in late July, but you must keep the seedbed consistently moist in the summer heat. Spring direct sowing is less reliable due to weather fluctuations.

What is the latest I can plant broccoli in Maryland?
For a fall crop, aim to have transplants in the ground by early September in central MD. This gives them enough time to mature before a hard freeze. You can push it slightly later with frost protection like row covers.

How do I protect broccoli from frost?
Broccoli can handle a light frost, which actually improves its flavor. For a hard freeze (below 28°F), cover plants with a row cover, old bedsheet, or frost cloth overnight.

Can I grow broccoli in containers in Maryland?
Absolutely. Choose a container at least 12-18 inches deep and wide. Use a high-quality potting mix and water frequently, as containers dry out fast. A patio with good sun is perfect.

Following this Maryland-specific schedule takes the guesswork out of growing broccoli. With the right timing and basic care, you’ll be enjoying homegrown broccoli from your own garden.