Planting Zone 3a
Min winter temp -40 to -35°F · last frost ~May · first frost ~September
In Zone 3a, the average last spring frost is around May and the first fall frost around September, about a 123-day growing season. Start tender crops indoors before the last frost and move them out once it passes.
Zone 3a planting schedule and calendar
| Crop | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Tomatoes | ● | ● | ● | |||||||||
| Peppers | ● | ● | ● | |||||||||
| Cucumbers | ● | ● | ● | |||||||||
| Lettuce | ● | ● | ● | |||||||||
| Zucchini | ● | ● | ● | |||||||||
| Carrots | ● | ● | ||||||||||
| Beans (bush) | ● | ● | ||||||||||
| Peas | ● | ● | ||||||||||
| Broccoli | ● | ● | ● | |||||||||
| Spinach | ● | ● | ||||||||||
| Kale | ● | ● | ● | |||||||||
| Onions | ● | ● | ● | |||||||||
| Garlic | ||||||||||||
| Potatoes | ● | ● | ||||||||||
| Squash (winter) | ● | ● | ● | |||||||||
| Corn | ● | ● | ||||||||||
| Radishes | ● | ● | ||||||||||
| Beets | ● | ● | ||||||||||
| Eggplant | ● | ● | ● | |||||||||
| Basil | ● | ● | ● | |||||||||
| Cilantro | ● | ● | ||||||||||
| Parsley | ● | ● | ● | |||||||||
| Pumpkins | ● | ● | ● | |||||||||
| Sunflowers | ● | ● |
What to plant this fall in Zone 3a
Fall planting in Zone 3a is arithmetic, not guesswork. The average first frost lands around September 15, so a crop needs its days to maturity, plus about two weeks for the slower growth of shortening days, to fit before then. Hardy crops get some of that back because they keep going past a light frost.
| Crop | Sow by | Fall harvest | Days to harvest |
|---|---|---|---|
| Radishes | Aug 25 | Sep 22 | ~28 |
| Cilantro | Aug 1 | Sep 15 | ~45 |
| Kale | Jul 31 | Sep 29 | ~60 |
| Beets | Jul 29 | Sep 22 | ~55 |
| Lettuce | Jul 27 | Sep 15 | ~50 |
| Carrots | Jul 21 | Sep 29 | ~70 |
| Broccoli | Jul 19 | Sep 22 | ~65 |
| Peas | Jul 17 | Sep 15 | ~60 |
Planted in fall to stand through a Zone 3a winter: garlic (Sep 15 to Oct 13) , onions (Aug 4 to Aug 25) , spinach (Aug 4 to Aug 18) , parsley (Aug 4 to Aug 18) .
More on the method: the fall planting calendar by zone, when to plant garlic and how to stretch your first frost date.
When to plant popular crops in Zone 3a
Tomatoes
~75 days
When to plant
Peppers
~80 days
When to plant
Cucumbers
~60 days
When to plant
Lettuce
~50 days
When to plantSeasonal reading for Zone 3a
- What to plant in October by zone
The October sowing and planting list for Zone 3a.
- What to plant in November by zone
What still goes in the ground in November in Zone 3a.
- Cold frame gardening by zone
How many weeks a cold frame adds to the Zone 3a season, and what to grow in it.
- October garden checklist
The jobs to finish before the first hard freeze in Zone 3a.
- Houseplants for low light
Something to grow while the Zone 3a garden is frozen.
- Winter sowing guide
Winter sowing dates for Zone 3a.
- When to start seeds indoors by zone
Indoor seed-starting dates counted from the Zone 3a last frost.
- What changed in the 2023 USDA zone map
Whether the 2023 USDA map moved Zone 3a, and what that changes.
- Companion planting chart
Which crops to plant together once you know your dates.
Nearby zones
Frequently asked questions
When is the last frost in Zone 3a?
On average, the last spring frost in Zone 3a is around May; the first fall frost is around September.
What can I grow in Zone 3a?
Nearly all common vegetables and herbs grow in Zone 3a; the difference is timing. Use the planting calendar above, calculated from Zone 3a frost dates.
What can I plant in the fall in Zone 3a?
radishes (sow by Aug 25), cilantro (sow by Aug 1), kale (sow by Jul 31), beets (sow by Jul 29), lettuce (sow by Jul 27), carrots (sow by Jul 21). Each date is counted back from the Zone 3a average first frost around September 15.
How long is the growing season in Zone 3a?
About 123 days between the average last spring and first fall frost.