Planting calendar

Zone 3 Planting Calendar: What to Plant Each Month

Last updated July 31, 2026

Zone 3 at a glance

Zone 3 runs winter lows of -40 to -30°F, and is conventionally taken to average its last spring frost around May 15 and its first fall frost around September 15 — about 123 frost-free days. One of the shortest growing seasons in the continental US. Short-season varieties and transplants matter more here than anywhere else.

Sow frost-tolerant crops (peas, spinach, radishes, lettuce, kale, carrots) 6 to 2 weeks before May 15. Plant warm-season crops (beans, zucchini, cucumbers, tomatoes, peppers) 1 to 3 weeks after it. Sow a second round of greens and roots about 10 to 12 weeks before September 15.

Typical regions in zone 3: Northern Minnesota, northern North Dakota, interior Alaska, high-elevation Rockies.

Month by month in zone 3

6 of the 12 months have something to plant in zone 3. Each window is the span in which that sowing or transplanting can safely happen.

March

Crop What to do Window
Onion Start indoors March 6 - March 20
Pepper Start indoors March 6 - March 20
Tomato Start indoors March 20 - April 3

April

Crop What to do Window
Cucumber Start indoors April 17 - April 24
Kale Start indoors April 3 - April 17
Tomato Start indoors March 20 - April 3
Carrot Direct sow outdoors April 24 - May 1
Kale Direct sow outdoors April 17 - May 1
Lettuce (leaf) Direct sow outdoors April 17 - May 1
Peas Direct sow outdoors April 3 - April 17
Radish Direct sow outdoors April 17 - May 1
Spinach Direct sow outdoors April 3 - April 17
Onion Transplant outdoors April 17 - May 1

May

Crop What to do Window
Bush beans Direct sow outdoors May 22 - May 29
Carrot Direct sow outdoors April 24 - May 1
Carrot Direct sow for a fall crop May 30 - June 13
Cucumber Direct sow outdoors May 29 - June 5
Kale Direct sow outdoors April 17 - May 1
Lettuce (leaf) Direct sow outdoors April 17 - May 1
Radish Direct sow outdoors April 17 - May 1
Zucchini Direct sow outdoors May 29 - June 5
Onion Transplant outdoors April 17 - May 1
Pepper Transplant outdoors May 29 - June 5
Tomato Transplant outdoors May 22 - May 29

June

Crop What to do Window
Carrot Direct sow for a fall crop May 30 - June 13
Cucumber Direct sow outdoors May 29 - June 5
Kale Direct sow for a fall crop June 14 - June 28
Lettuce (leaf) Direct sow for a fall crop June 24 - July 8
Peas Direct sow for a fall crop June 9 - June 23
Spinach Direct sow for a fall crop June 29 - July 13
Zucchini Direct sow outdoors May 29 - June 5
Pepper Transplant outdoors May 29 - June 5

July

Crop What to do Window
Lettuce (leaf) Direct sow for a fall crop June 24 - July 8
Radish Direct sow for a fall crop July 19 - August 2
Spinach Direct sow for a fall crop June 29 - July 13

August

Crop What to do Window
Radish Direct sow for a fall crop July 19 - August 2

No first sowing window falls in January, February, September, October, November, December for zone 3. That does not mean the garden is idle. Each crop above carries one spring window, and several of them are routinely re-sown every 2 to 3 weeks while conditions allow — Radish, Lettuce (leaf), Spinach, Bush beans, Kale, Carrot. So a gap here means “nothing new starts this month”, not “nothing can be planted”.

Genuinely quiet months are the deep-winter ones in cold zones and the peak-heat ones in zones 8 to 10, when cool-season crops bolt and it is worth waiting for the fall sowing dates instead.

Every crop, sowing to harvest

One row per crop, with the indoor start where it applies, the outdoor planting window, the second fall sowing where the season allows it, and the earliest realistic harvest.

Harvest dates assume the earliest outdoor planting in the window and the crop's published days-to-harvest range. Weather moves all of it.
Crop Start indoors Plant outdoors Fall sowing Harvest from
Radish - Direct sow outdoors: April 17 - May 1 July 19 - August 2 May 9 - May 17
Lettuce (leaf) - Direct sow outdoors: April 17 - May 1 June 24 - July 8 June 1 - June 11
Spinach - Direct sow outdoors: April 3 - April 17 June 29 - July 13 May 13 - May 23
Bush beans - Direct sow outdoors: May 22 - May 29 - July 11 - July 21
Zucchini - Direct sow outdoors: May 29 - June 5 - July 13 - July 23
Kale April 3 - April 17 Direct sow outdoors: April 17 - May 1 June 14 - June 28 June 6 - June 21
Peas - Direct sow outdoors: April 3 - April 17 June 9 - June 23 June 2 - June 12
Carrot - Direct sow outdoors: April 24 - May 1 May 30 - June 13 June 28 - July 13
Cucumber April 17 - April 24 Direct sow outdoors: May 29 - June 5 - July 23 - August 2
Tomato March 20 - April 3 Transplant outdoors: May 22 - May 29 - July 21 - August 15
Pepper March 6 - March 20 Transplant outdoors: May 29 - June 5 - August 7 - August 27
Onion March 6 - March 20 Transplant outdoors: April 17 - May 1 - July 26 - August 15

Growing in zone 3

One of the shortest growing seasons in the continental US. Short-season varieties and transplants matter more here than anywhere else.

Soil beats calendar. Extension guidance for the hardiest crops is “as soon as the soil can be worked” or “as soon as the soil thaws” — not a fixed date. If you cannot crumble a handful of soil in your fist, wait, whatever the table says. Warm-season crops have a matching rule: beans want 60°F soil, cucumbers and squash 70°F.

This matters most in zone 3. The earliest spring windows above assume the ground has thawed and is workable, and in a late spring it may still be frozen or waterlogged on those dates. A raised bed, which warms 2 to 3 weeks earlier than open ground, is the reliable way to hit the early dates here.

Where these dates come from. A USDA hardiness zone describes average annual extreme minimum WINTER temperature — it is a winter-survival rating for perennials, not a frost-date band. The frost dates below are widely-used approximations for each zone, not official USDA figures, and a single zone spans hundreds of miles. Treat them as a default guess and replace them with your own local averages wherever you have them.

You can enter your own frost dates in the interactive calendar and every window on it recalculates from your numbers. Look up your local averages on the NOAA last-spring-freeze map. Note that an “average” frost date is the point where the chance of freezing drops below 50 percent, so for tender crops it is worth waiting a week or two past it.

Other zones: zone 4 , zone 5 , zone 6 , zone 7 , zone 8 , zone 9 , zone 10 . Or use the interactive calendar to check a single month.

Zone 3 questions

When is the last frost in zone 3?

Zone 3 is conventionally taken to average its last spring frost around May 15 and its first fall frost around September 15, giving roughly 123 frost-free days. Be aware that a hardiness zone is defined by winter minimum temperature, not by frost dates — these are widely-used approximations, not official USDA figures. Get your real dates from the NOAA freeze-date map or your county cooperative extension office.

What can I plant now in zone 3?

Use the month-by-month table on this page. The pattern is: frost-tolerant crops like peas, spinach and radishes go in 6 to 2 weeks before May 15; warm-season crops like beans, zucchini and tomatoes go in 1 to 3 weeks after it; and cool-season crops get a second sowing about 10 to 12 weeks before September 15.

Can I grow tomatoes in zone 3?

Yes. In zone 3, start tomato seed indoors 6 to 8 weeks before May 15 or buy a seedling, then transplant 1 to 2 weeks after the last frost once nights stay above 50°F. With 123 frost-free days there is enough season for early and mid-season varieties, though large beefsteak types are a gamble — choose cherry or early varieties rated under 70 days.

How many harvests can I get in zone 3?

One main round plus a tight fall sowing of the fastest crops. Radishes, spinach and lettuce can still be squeezed in after an early crop comes out.

Does a raised bed change these dates in zone 3?

Yes, in spring. A raised bed warms 2 to 3 weeks earlier than open ground, so you can bring the early sowings forward by up to two weeks. Autumn dates are unchanged, since the first frost arrives on the same day regardless of your setup.

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