Planting Zone 4a
Min winter temp -30 to -25°F · last frost ~May · first frost ~September
In Zone 4a, the average last spring frost is around May and the first fall frost around September, about a 135-day growing season. Start tender crops indoors before the last frost and move them out once it passes.
Zone 4a 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 4a
Fall planting in Zone 4a is arithmetic, not guesswork. The average first frost lands around September 22, 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 | Sep 1 | Sep 29 | ~28 |
| Cilantro | Aug 8 | Sep 22 | ~45 |
| Kale | Aug 7 | Oct 6 | ~60 |
| Beets | Aug 5 | Sep 29 | ~55 |
| Lettuce | Aug 3 | Sep 22 | ~50 |
| Carrots | Jul 28 | Oct 6 | ~70 |
| Broccoli | Jul 26 | Sep 29 | ~65 |
| Peas | Jul 24 | Sep 22 | ~60 |
| Zucchini | Jul 1 | Aug 25 | ~55 |
| Beans (bush) | Jul 1 | Aug 25 | ~55 |
Planted in fall to stand through a Zone 4a winter: garlic (Sep 22 to Oct 20) , onions (Aug 11 to Sep 1) , spinach (Aug 11 to Aug 25) , parsley (Aug 11 to Aug 25) .
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 4a
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 4a
- What to plant in October by zone
The October sowing and planting list for Zone 4a.
- What to plant in November by zone
What still goes in the ground in November in Zone 4a.
- Cold frame gardening by zone
How many weeks a cold frame adds to the Zone 4a season, and what to grow in it.
- October garden checklist
The jobs to finish before the first hard freeze in Zone 4a.
- Houseplants for low light
Something to grow while the Zone 4a garden is frozen.
- Winter sowing guide
Winter sowing dates for Zone 4a.
- When to start seeds indoors by zone
Indoor seed-starting dates counted from the Zone 4a last frost.
- What changed in the 2023 USDA zone map
Whether the 2023 USDA map moved Zone 4a, 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 4a?
On average, the last spring frost in Zone 4a is around May; the first fall frost is around September.
What can I grow in Zone 4a?
Nearly all common vegetables and herbs grow in Zone 4a; the difference is timing. Use the planting calendar above, calculated from Zone 4a frost dates.
What can I plant in the fall in Zone 4a?
radishes (sow by Sep 1), cilantro (sow by Aug 8), kale (sow by Aug 7), beets (sow by Aug 5), lettuce (sow by Aug 3), carrots (sow by Jul 28). Each date is counted back from the Zone 4a average first frost around September 22.
How long is the growing season in Zone 4a?
About 135 days between the average last spring and first fall frost.