What to plant in August in Minnesota
In Minnesota (MN), August sits about 6 weeks before the average first fall frost (September 28). The state averages 145 frost-free days a year (last frost May 6, first frost September 28; USDA zones 3a, 3b, 4a, 4b, 5a).
22 crops have a sowing or planting window this month, including beet, cilantro / coriander, bok choy / pak choi, borage, dill, fava bean (broad bean) - and 17 of those windows close during August.
Dates here come from Minnesota frost dates (last frost May 6, first frost Sep 28). For one crop in detail, see when to plant beet, lettuce or spinach in Minnesota.
Minnesota: planting activity through the year
Last chance in August
Beet (sow for a fall crop, by Aug 3) · Cilantro / Coriander (sow for a fall crop, by Aug 3) · Bok Choy / Pak Choi (sow for a fall crop, by Aug 10) · Borage (sow for a fall crop, by Aug 10) · Dill (sow for a fall crop, by Aug 10) · Fava Bean (Broad Bean) (sow for a fall crop, by Aug 10) · Green Onion / Scallion (sow for a fall crop, by Aug 10) · Kohlrabi (sow for a fall crop, by Aug 10) · Lettuce (sow for a fall crop, by Aug 10) · Mache (Corn Salad) (sow for a fall crop, by Aug 10) · Mizuna (sow for a fall crop, by Aug 10) · Rapini (Broccoli Raab) (sow for a fall crop, by Aug 10) · Chervil (sow for a fall crop, by Aug 17) · Mustard Greens (sow for a fall crop, by Aug 17) · Spinach (sow for a fall crop, by Aug 17) · Tatsoi (sow for a fall crop, by Aug 17) · Turnip (sow for a fall crop, by Aug 17)
For fall and winter harvests (20)
Sowings counted back from Minnesota's first fall frost, so the crop matures before the cold - or, for garlic and similar, planted after it.
| Crop | What to do | Window | This month |
|---|---|---|---|
| Beet | Sow for a fall crop | Jul 17 – Aug 3 | Last chance - ends Aug 3 |
| Cilantro / Coriander | Sow for a fall crop | Jul 17 – Aug 3 | Last chance - ends Aug 3 |
| Bok Choy / Pak Choi | Sow for a fall crop | Jul 24 – Aug 10 | Last chance - ends Aug 10 |
| Borage | Sow for a fall crop | Jul 24 – Aug 10 | Last chance - ends Aug 10 |
| Dill | Sow for a fall crop | Jul 24 – Aug 10 | Last chance - ends Aug 10 |
| Fava Bean (Broad Bean) | Sow for a fall crop | Jul 24 – Aug 10 | Last chance - ends Aug 10 |
| Green Onion / Scallion | Sow for a fall crop | Jul 24 – Aug 10 | Last chance - ends Aug 10 |
| Kohlrabi | Sow for a fall crop | Jul 24 – Aug 10 | Last chance - ends Aug 10 |
| Lettuce | Sow for a fall crop | Jul 24 – Aug 10 | Last chance - ends Aug 10 |
| Mache (Corn Salad) | Sow for a fall crop | Jul 24 – Aug 10 | Last chance - ends Aug 10 |
| Mizuna | Sow for a fall crop | Jul 24 – Aug 10 | Last chance - ends Aug 10 |
| Rapini (Broccoli Raab) | Sow for a fall crop | Jul 24 – Aug 10 | Last chance - ends Aug 10 |
| Chervil | Sow for a fall crop | Jul 31 – Aug 17 | Last chance - ends Aug 17 |
| Mustard Greens | Sow for a fall crop | Jul 31 – Aug 17 | Last chance - ends Aug 17 |
| Spinach | Sow for a fall crop | Jul 31 – Aug 17 | Last chance - ends Aug 17 |
| Tatsoi | Sow for a fall crop | Jul 31 – Aug 17 | Last chance - ends Aug 17 |
| Turnip | Sow for a fall crop | Jul 31 – Aug 17 | Last chance - ends Aug 17 |
| Arugula | Sow for a fall crop | Aug 7 – Aug 24 | Aug 7 – Aug 24 |
| Watercress | Sow for a fall crop | Aug 7 – Aug 24 | Aug 7 – Aug 24 |
| Radish | Sow for a fall crop | Aug 14 – Aug 31 | Aug 14 – Aug 31 |
Keep sowing (succession)
Repeat sowings of crops already in the ground, for a steady harvest instead of a glut.
- Basil: sow again on Aug 12
- Amaranth (Leaf): sow again on Aug 5
Harvesting in August
First harvests expected this month from crops sown or planted on time earlier in the season.
Planting dates for popular crops in Minnesota
Every crop has its own full-year dates for Minnesota: indoor start, transplant or direct sowing, and harvest.
Fall garden season: August garden jobs in Minnesota
- The average first frost is September 28, about 6 weeks away. Pick tender crops (tomatoes, peppers, squash, beans) before it, or cover them on cold nights.
- Still time to sow or plant: beet, cilantro / coriander, bok choy / pak choi, borage, dill, fava bean (broad bean). Fast greens and radishes are the safest bets this late.
- Row cover buys 4-6°F of frost protection and weeks of extra harvest - see season extension.
- Pull finished crops and sow a cover crop (cereal rye or crimson clover) into empty beds before the soil gets cold.
USDA zone chart for Minnesota
Minnesota spans USDA zones 3a, 3b, 4a, 4b, 5a. Colder zones, usually higher or further inland, have a later last spring frost and an earlier first fall frost than the state average.
Questions gardeners ask
What vegetables can I plant in Minnesota in August?
22 crops have a window in August: beet, cilantro / coriander, bok choy / pak choi, borage, dill, fava bean (broad bean), green onion / scallion, kohlrabi, lettuce, mache (corn salad) and more. The tables above give the exact dates for each.
Is it too late to plant garlic in Minnesota in August?
Not too late - it's actually a little early. In Minnesota the next garlic window opens around October 9: plant in fall, after first frost.
Is it too late to plant tomatoes in Minnesota in August?
For this year, yes - the tomato windows in Minnesota have closed. The next step is to start seeds indoors from about March 11.
When is the first frost in Minnesota?
The statewide average first fall frost is around September 28 and the last spring frost around May 6. Your town can be a week or two either side - look yours up by ZIP code.
What can I harvest in Minnesota in August?
From plantings made on time: potato, tomato, sweet corn, sweet marjoram, onion, shallot, bitter melon, bell pepper, southern pea (cowpea), thyme.
What to plant in August in other states
Dates are computed from Minnesota’s statewide average frost dates (from NOAA/NCEI climate normals) and each crop’s timing in our crop database. Your garden may be a week or two either side - for dates tuned to your ZIP code, use the planting calendar.