Question 1

When should I plant lettuce in ZIP 48226?

Accepted Answer

In ZIP 48226, the main lettuce target is around Apr 21, based on the representative Detroit frost station and USDA zone 6b.

Question 2

When should I start lettuce seeds indoors in 48226?

Accepted Answer

Start lettuce seeds indoors in ZIP 48226 around Apr 7, about 28 days before the May 5 last-frost estimate.

Question 3

When is the last frost in Detroit?

Accepted Answer

Detroit (ZIP 48226) has an average last spring frost around May 5, based on the representative Detroit frost station.

Question 4

When is the first frost in Detroit?

Accepted Answer

Detroit (ZIP 48226) has an average first fall frost around Oct 15, leaving about 163 frost-free days.

Question 5

Is this a guaranteed planting date?

Accepted Answer

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

Step	Date	How to use it
Start Indoors	April 7, 2026	Start seeds under lights or in a bright indoor seed-starting space.
Transplant Outdoors	April 21, 2026	Move hardened-off seedlings outside after the frost-risk window.
Direct Sow	April 21, 2026	Sow seed outside when the crop and soil can handle the window.

Start lettuce seeds indoors around Apr 7

Lettuce dates for Detroit, MI