Portland, ME · zone 5b · ~172 frost-free days
When to plant in Portland: frost dates and zone 5b.
In Portland, the typical last spring frost lands around Apr 26 and the first fall frost around Oct 15, giving you about 172 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 Portland, keyed to your frost.
| Crop | Start indoors | Spring sow / set out | Fall sow |
|---|---|---|---|
| Tomato, slicing | Mar 22 to May 22 | May 3 to Jul 3 | — |
| Lettuce, leaf | — | Mar 19 to May 3 | Aug 1 to Sep 30 |
| Carrot | — | Mar 19 to Apr 21 | Jul 20 to Aug 15 |
| Bush Bean | — | Apr 26 to Jun 16 | Jul 1 to Aug 3 |
| Cucumber, slicing | — | May 3 to Jul 29 | — |
| Pepper, bell | Mar 31 to May 22 | May 12 to Jul 3 | — |
| Kale | Feb 5 to Mar 5 | Mar 19 to Apr 16 | Jul 15 to Aug 30 |
| Spinach | — | Mar 5 to Apr 16 | Aug 1 to Sep 19 |
Portland sits in Zone 5b, 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 Portland 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 04101 in about 60 seconds.
Portland planting questions
What planting zone is Portland, ME?+
Portland is in USDA hardiness zone 5b. Growing zone, gardening zone, and planting zone all mean the same thing: the USDA number, 5b 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 Portland?+
The typical last spring frost in Portland, ME is around Apr 26. 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 Portland?+
The typical first fall frost in Portland, ME arrives around Oct 15, closing a growing season of roughly 172 frost-free days. Count backward from it to find the last date a fall crop can still finish.
What can I plant now in Portland?+
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 Apr 26. The table above shows each crop's window; the free planner turns your ZIP into an exact, dated calendar.