Delaware planting calendar

When to plant brussels sprouts in Delaware — sow, transplant & harvest dates

Delaware is mostly USDA zone 7b (range 7a-8a). Dates below are derived from brussels sprouts's frost tolerance and Delaware's frost window — not generic national averages.

Brussels Sprouts planting timetable for Delaware

Stage	When in Delaware	Anchor
Start seeds indoors	late January (January 21)	12 weeks before the last frost (mid-April)
Transplant outside	early April (April 1)	14 days before the last frost (mid-April)
First harvest (estimate)	late June (June 30)	~90 days from transplant

Dates are state-wide averages for the dominant zone. Local microclimates — elevation, urban heat, coastal moderation — can shift the window by 1-2 weeks. Use the frost-date calculator for a date tuned to your town.

Why Delaware's climate shifts the brussels sprouts dates

Delaware's last spring frost averages mid-April and first fall frost late October, which sets the whole planting clock. Delaware is small and mild, moderated by the Atlantic and Delaware Bay, with a long, productive mid-Atlantic season. Sow early — brussels sprouts bolt once daytime temperatures hold above 24 °C, so the earlier they go in, the longer the harvest.

Brussels sprouts are a long-season crop — transplant outdoors 2–3 weeks before the last spring frost once seedlings are 10–15 cm tall, or start a fall crop by counting back 90–100 days from the first fall frost and setting transplants then. Flavour sweetens after the first hard frost (below -2 °C), making them one of the few vegetables that actually improves with autumn cold. Zones 9–10 can grow them as a winter crop but the lack of hard frost reduces flavour development.

Frost-risk note

Don't plant before mid-April — a hard freeze can still set young plants back. In the northern Piedmont near Wilmington (zone 7a) the safe date runs a week or two later.

Regional variation within Delaware

the northern Piedmont near Wilmington (zone 7a) runs roughly 1-2 weeks behind the state average; the Atlantic coast and lower Delmarva (zone 8a) can plant 1-2 weeks earlier.

Wilmington — USDA zone 7b
Dover — USDA zone 7b
Newark — USDA zone 7b
Rehoboth Beach — USDA zone 8a

What else to plant in Delaware around then

The same early window suits peas, lettuce, spinach, and onion sets.

Quick-grow guide

Sun: Full sun — 6+ hours direct.
Soil temperature for germination: 7-29 °C (45-85 °F).
Spacing: 18-24 inches (45-60 cm) between plants.
Days to harvest: ~90 days from planting out.

Frequently asked questions

When is the best time to plant brussels sprouts in Delaware?

In Delaware (mostly USDA zone 7b), sow brussels sprouts indoors around late January, transplant outdoors early April (before the last frost, mid-April), and harvest from late June. Brussels Sprouts are cold-hardy — they tolerate frost and actively prefer cool weather, so they go in well before the last spring frost and bolt in summer heat.

What USDA zone is Delaware?

Most of Delaware sits in USDA hardiness zone 7b, with the state spanning roughly 7a-8a from the northern Piedmont near Wilmington (zone 7a) to the Atlantic coast and lower Delmarva (zone 8a). The last spring frost averages mid-April and the first fall frost late October.

Can you grow brussels sprouts in Delaware?

Yes. Delaware's dominant zone 7b supports brussels sprouts — the key is timing. Brussels Sprouts are cold-hardy — they tolerate frost and actively prefer cool weather, so they go in well before the last spring frost and bolt in summer heat.

Does the planting date change across Delaware?

the northern Piedmont near Wilmington (zone 7a) runs roughly 1-2 weeks behind the state average; the Atlantic coast and lower Delmarva (zone 8a) can plant 1-2 weeks earlier.

What else can I plant in Delaware around the same time?

The same early window suits peas, lettuce, spinach, and onion sets.

Source and methodology

State zone spans from the USDA Plant Hardiness Zone Map (2023); frost-date averages from NOAA Climate Data Online. Hot-state two-season timing cross-checked against the UF/IFAS Florida Gardening Calendar and the University of Arizona Cooperative Extension planting calendar. Curated by the Growli editorial team.