When should I plant cucumbers in ZIP 20001?

In ZIP 20001, the main cucumbers target is around Apr 25, based on the representative Washington frost station and USDA zone 7b.

When should I start cucumbers seeds indoors in 20001?

Start cucumbers seeds indoors in ZIP 20001 around Mar 25, about 21 days before the Apr 15 last-frost estimate.

Is this a guaranteed planting date?

No. GrowZone uses frost-date estimates, hardiness zones, and crop timing rules for planning. Local microclimates and current weather can shift the right date.

ZIP 20001 planting calendar

When to plant cucumbers in Washington, DC - Zone 7b

Q: When is the first frost in Washington?

Washington (ZIP 20001) has an average first fall frost around Nov 5, leaving about 204 frost-free days.

In ZIP 20001, plant cucumbers around Apr 25; this uses the Washington frost station, USDA zone 7b, and cucumbers timing rules.

Your Washington calendar has a 204-day estimated frost-free season. This estimate uses the representative Washington frost station, USDA zone 7b, and cucumbers timing rules.

Source: washington-reagan frost station, USDA zone 7b, last updated 2026-06-28. Verify locally before planting high-value crops because microclimates, current weather, and yard exposure can move the safe date.

USDA zone 7b Washington frost station University of the District of Columbia Extension Updated 2026-06-28

Read the method

Answer first

When to start cucumbers seeds indoors in Washington

In ZIP 20001, start cucumbers seeds indoors around Mar 25, about 21 days before the Apr 15 last-frost estimate.

Start cucumbers seeds indoors in Washington around Mar 25, about 21 days before the Apr 15 last-frost estimate.

Seed starting schedule

Cucumbers dates for Washington, DC

Step	Date	How to use it
Start Indoors	March 25, 2026	Start seeds under lights or in a bright indoor seed-starting space.
Transplant Outdoors	April 25, 2026	Move hardened-off seedlings outside after the frost-risk window.
Direct Sow	April 25, 2026	Sow seed outside when the crop and soil can handle the window.

Last frost

When is the last frost in Washington?

Washington (ZIP 20001) has an average last spring frost around Apr 15.

First frost

When is the first frost in Washington?

The average first fall frost is around Nov 5, giving about 204 frost-free days.

Season map

Cucumbers windows by month

JanFebMarAprMayJunJulAugSepOctNovDec

Start indoors

Mar 25

Direct sow

Apr 25

Transplant

Apr 25

Harvest

Jun 24

Frost watch

Sep 6

Reminder workflow

Every date has a next action

Start cucumbers indoorsMar 25

Last frost windowApr 15

Direct sow cucumbersApr 25

Transplant cucumbersApr 25

First cucumbers harvest windowJun 24

Last cucumbers sowing targetSep 6

Signal	Value	Why it matters
Last frost estimate	April 15, 2026	Warm-season transplant risk starts falling after this window.
First frost estimate	November 5, 2026	Fall planting counts backward from this date.
Season length	204 days	Longer seasons can support succession crops.
Spacing	12-18 in	Airflow and root space affect yield.
Soil temperature	65 F+	Seeds and transplants stall in cold soil.

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Local data

Why this date changes by ZIP

Washington frost history and USDA zone 7b shift the safe planting window. GrowZone uses a local representative station instead of one national rule.

University of the District of Columbia Extension is the kind of local source to verify against when a crop is expensive, weather is unusual, or your yard has a cold pocket.

Crop note

Cucumbers timing notes

Use a trellis if space is tight and keep soil evenly moist. Cucumbers prefers full sun, 12-18 in spacing, and soil near 65 F+.

For fall, count backward from Nov 5. A conservative last sowing target is around Sep 6.