Ann Arbor, MI · zone 6a · ~157 frost-free days
When to plant in Ann Arbor: frost dates and zone 6a.
In Ann Arbor, the typical last spring frost lands around May 5 and the first fall frost around Oct 9, giving you about 157 frost-free days. Cool-season crops go out before the last frost; warm-season crops wait until after it.
The 2026 windows
Sow dates for Ann Arbor, keyed to your frost.
| Crop | Start indoors | Spring sow / set out | Fall sow |
|---|---|---|---|
| Tomato, slicing | Mar 31 to May 31 | May 12 to Jul 12 | — |
| Lettuce, leaf | — | Mar 28 to May 12 | Jul 26 to Sep 24 |
| Carrot | — | Mar 28 to Apr 30 | Jul 14 to Aug 9 |
| Bush Bean | — | May 5 to Jun 25 | Jun 25 to Jul 28 |
| Cucumber, slicing | — | May 12 to Jul 23 | — |
| Pepper, bell | Apr 9 to May 31 | May 21 to Jul 12 | — |
| Kale | Feb 14 to Mar 14 | Mar 28 to Apr 25 | Jul 9 to Aug 24 |
| Spinach | — | Mar 14 to Apr 25 | Jul 26 to Sep 13 |
Ann Arbor sits in Zone 6a, but two gardens in the same city can be a week or two apart. The planner works from your ZIP code's frost dates, not the zone, so the dates land right for your block, not the metro average.
Build your Ann Arbor garden plan.
Tell the free planner what you want to eat and who you're feeding. It returns plant counts, spacing, and frost-safe sow dates for ZIP 48104 in about 60 seconds.
Ann Arbor planting questions
What planting zone is Ann Arbor, MI?+
Ann Arbor is in USDA hardiness zone 6a. Growing zone, gardening zone, and planting zone all mean the same thing: the USDA number, 6a here. It tells you what survives winter, not when to plant. Frost dates set your planting time, and the free planner uses your exact ZIP code's frost dates, which can differ by weeks across one metro.
When is the last frost date in Ann Arbor?+
The typical last spring frost in Ann Arbor, MI is around May 5. That is an average from local history, not a guarantee, so tender crops like tomatoes and peppers are safer with a week of buffer after it.
When is the first frost date in Ann Arbor?+
The typical first fall frost in Ann Arbor, MI arrives around Oct 9, closing a growing season of roughly 157 frost-free days. Count backward from it to find the last date a fall crop can still finish.
What can I plant now in Ann Arbor?+
It depends on the date. Cool-season crops like lettuce, kale, and spinach go out weeks before the last frost; warm-season crops like tomatoes and peppers wait until after May 5. The table above shows each crop's window; the free planner turns your ZIP into an exact, dated calendar.