Kentucky planting calendar

When to plant summer squash in Kentucky — sow, transplant & harvest dates

Kentucky is mostly USDA zone 6b (range 6a-7b). Dates below are derived from summer squash's frost tolerance and Kentucky's frost window — not generic national averages.

Summer squash planting timetable for Kentucky

Stage	When in Kentucky	Anchor
Start seeds indoors	late March (March 25)	3 weeks before the last frost (mid-April)
Transplant outside	late April (April 29)	14 days after the last frost (mid-April)
First harvest (estimate)	late June (June 23)	~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 Kentucky's climate shifts the summer squash dates

Kentucky's last spring frost averages mid-April and first fall frost mid-October, which sets the whole planting clock. Kentucky has a mild four-season climate with a long, humid summer and a winter that rarely tests hardy perennials. Wait for warm soil — summer squash stall in cold ground even after the air warms, so don't rush them out.

Summer squash (zucchini, yellow crookneck, pattypan) wants the same warm soil as cucumbers — 18 °C minimum at sowing depth. A single plant can outproduce a small family once it gets going, so don't over-plant.

Frost-risk note

Don't plant before mid-April — even a light frost will kill seedlings overnight. In the eastern Appalachian highlands (zone 6a) the safe date runs a week or two later.

Regional variation within Kentucky

the eastern Appalachian highlands (zone 6a) runs roughly 1-2 weeks behind the state average; the Ohio River valley around Louisville (zone 7b) can plant 1-2 weeks earlier.

Louisville — USDA zone 7a
Lexington — USDA zone 6b
Bowling Green — USDA zone 7a
Covington — USDA zone 6b

What else to plant in Kentucky around then

Pair the post-frost slot with other warm-season crops — peppers, beans, squash, and cucumbers.

Quick-grow guide

Sun: Full sun — 6-8 hours direct.
Soil temperature for germination: 21-29 °C (70-85 °F).
Spacing: 24-36 inches (60-90 cm) between plants.
Days to harvest: ~55 days from planting out.

Frequently asked questions

When is the best time to plant summer squash in Kentucky?

In Kentucky (mostly USDA zone 6b), sow summer squash indoors around late March, transplant outdoors late April (after the last frost, mid-April), and harvest from late June. Summer squash are frost-tender — a single light frost kills seedlings, so they only go outside once frost danger has fully passed and the soil is warm.

What USDA zone is Kentucky?

Most of Kentucky sits in USDA hardiness zone 6b, with the state spanning roughly 6a-7b from the eastern Appalachian highlands (zone 6a) to the Ohio River valley around Louisville (zone 7b). The last spring frost averages mid-April and the first fall frost mid-October.

Can you grow summer squash in Kentucky?

Yes. Kentucky's dominant zone 6b supports summer squash — the key is timing. Summer squash are frost-tender — a single light frost kills seedlings, so they only go outside once frost danger has fully passed and the soil is warm.

Does the planting date change across Kentucky?

the eastern Appalachian highlands (zone 6a) runs roughly 1-2 weeks behind the state average; the Ohio River valley around Louisville (zone 7b) can plant 1-2 weeks earlier.

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

Pair the post-frost slot with other warm-season crops — peppers, beans, squash, and cucumbers.

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.