Vermont planting calendar

When to plant kohlrabi in Vermont — sow, transplant & harvest dates

Vermont is mostly USDA zone 4b (range 3b-5b). Dates below are derived from kohlrabi's frost tolerance and Vermont's frost window — not generic national averages.

Kohlrabi planting timetable for Vermont

Stage	When in Vermont	Anchor
Start seeds indoors	early April (April 10)	5 weeks before the last frost (mid-May)
Transplant outside	late April (April 24)	21 days before the last frost (mid-May)
First harvest (estimate)	mid-June (June 18)	~55 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 Vermont's climate shifts the kohlrabi dates

Vermont's last spring frost averages mid-May and first fall frost late September, which sets the whole planting clock. Vermont is a cold, short-season state. The Champlain Valley is the mildest pocket; the mountains and Northeast Kingdom are markedly colder. Sow early — kohlrabi bolt once daytime temperatures hold above 24 °C, so the earlier they go in, the longer the harvest.

Kohlrabi is a fast-maturing brassica that tolerates light frost down to about -4 °C but turns woody and pithy when daytime temperatures exceed 27 °C; transplant or direct-sow 3–4 weeks before the last spring frost for a summer harvest, or time a second sowing so plants mature in the cool days of early autumn. Harvest promptly when the swollen stem reaches 5–7 cm (2–3 inches) in diameter — larger bulbs become fibrous. Succession-sow every 3 weeks to extend the harvest window.

Frost-risk note

Don't plant before mid-May — a hard freeze can still set young plants back. In the Green Mountains and Northeast Kingdom (zone 3b) the safe date runs a week or two later.

Regional variation within Vermont

the Green Mountains and Northeast Kingdom (zone 3b) runs roughly 1-2 weeks behind the state average; the Champlain Valley and southern river valleys (zone 5b) can plant 1-2 weeks earlier.

Burlington — USDA zone 5a
Montpelier — USDA zone 4b
Rutland — USDA zone 5a
Brattleboro — USDA zone 5b

What else to plant in Vermont 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: 6-9 inches (15-23 cm) between plants.
Days to harvest: ~55 days from planting out.

Frequently asked questions

When is the best time to plant kohlrabi in Vermont?

In Vermont (mostly USDA zone 4b), sow kohlrabi indoors around early April, transplant outdoors late April (before the last frost, mid-May), and harvest from mid-June. Kohlrabi are half-hardy — young plants shrug off a light frost but not a hard freeze, so sowing can start a couple of weeks before the last spring frost.

What USDA zone is Vermont?

Most of Vermont sits in USDA hardiness zone 4b, with the state spanning roughly 3b-5b from the Green Mountains and Northeast Kingdom (zone 3b) to the Champlain Valley and southern river valleys (zone 5b). The last spring frost averages mid-May and the first fall frost late September.

Can you grow kohlrabi in Vermont?

Yes. Vermont's dominant zone 4b supports kohlrabi — the key is timing. Kohlrabi are half-hardy — young plants shrug off a light frost but not a hard freeze, so sowing can start a couple of weeks before the last spring frost.

Does the planting date change across Vermont?

the Green Mountains and Northeast Kingdom (zone 3b) runs roughly 1-2 weeks behind the state average; the Champlain Valley and southern river valleys (zone 5b) can plant 1-2 weeks earlier.

What else can I plant in Vermont 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.