My Planting Calendar

What to plant in August in zone 4

USDA zone 4 has winter lows of -30 to -20°F, a typical last spring frost around May 10 and first fall frost around Sep 25, roughly 135 frost-free days. August is the "fall garden season" there.

19 crops have a sowing or planting window this month, including bok choy / pak choi, borage, dill, fava bean (broad bean), green onion / scallion, kohlrabi - and 15 of those windows close during August.

Dates come from the typical frost dates of USDA zone 4 (last frost May 10, first frost Sep 25). A zone covers many climates, so for dates tuned to your town use the planting calendar, or pick your state below.

Fall garden seasonSow or plant: 19Start indoors: 0Harvesting: 61

Zone 4: planting activity through the year

0
5
40
64
84
53
37
19
1
2
0
0
JanFebMarAprMayJunJulAugSepOctNovDec
Frost riskFrost-free: May 10 – Sep 25
Bars count the vegetables, herbs and fruit with a sowing or planting window in each month, from the state’s average frost dates. 19 have one in August; the busiest month is May (84).

Last chance in August

Bok Choy / Pak Choi (sow for a fall crop, by Aug 7) · Borage (sow for a fall crop, by Aug 7) · Dill (sow for a fall crop, by Aug 7) · Fava Bean (Broad Bean) (sow for a fall crop, by Aug 7) · Green Onion / Scallion (sow for a fall crop, by Aug 7) · Kohlrabi (sow for a fall crop, by Aug 7) · Lettuce (sow for a fall crop, by Aug 7) · Mache (Corn Salad) (sow for a fall crop, by Aug 7) · Mizuna (sow for a fall crop, by Aug 7) · Rapini (Broccoli Raab) (sow for a fall crop, by Aug 7) · Chervil (sow for a fall crop, by Aug 14) · Mustard Greens (sow for a fall crop, by Aug 14) · Spinach (sow for a fall crop, by Aug 14) · Tatsoi (sow for a fall crop, by Aug 14) · Turnip (sow for a fall crop, by Aug 14)

For fall and winter harvests (18)

Sowings counted back from zone 4's first fall frost, so the crop matures before the cold - or, for garlic and similar, planted after it.

CropWhat to doWindowThis month
Bok Choy / Pak ChoiSow for a fall cropJul 21 – Aug 7Last chance - ends Aug 7
BorageSow for a fall cropJul 21 – Aug 7Last chance - ends Aug 7
DillSow for a fall cropJul 21 – Aug 7Last chance - ends Aug 7
Fava Bean (Broad Bean)Sow for a fall cropJul 21 – Aug 7Last chance - ends Aug 7
Green Onion / ScallionSow for a fall cropJul 21 – Aug 7Last chance - ends Aug 7
KohlrabiSow for a fall cropJul 21 – Aug 7Last chance - ends Aug 7
LettuceSow for a fall cropJul 21 – Aug 7Last chance - ends Aug 7
Mache (Corn Salad)Sow for a fall cropJul 21 – Aug 7Last chance - ends Aug 7
MizunaSow for a fall cropJul 21 – Aug 7Last chance - ends Aug 7
Rapini (Broccoli Raab)Sow for a fall cropJul 21 – Aug 7Last chance - ends Aug 7
ChervilSow for a fall cropJul 28 – Aug 14Last chance - ends Aug 14
Mustard GreensSow for a fall cropJul 28 – Aug 14Last chance - ends Aug 14
SpinachSow for a fall cropJul 28 – Aug 14Last chance - ends Aug 14
TatsoiSow for a fall cropJul 28 – Aug 14Last chance - ends Aug 14
TurnipSow for a fall cropJul 28 – Aug 14Last chance - ends Aug 14
ArugulaSow for a fall cropAug 4 – Aug 21Aug 4 – Aug 21
WatercressSow for a fall cropAug 4 – Aug 21Aug 4 – Aug 21
RadishSow for a fall cropAug 11 – Aug 28Aug 11 – Aug 28

Harvesting in August

First harvests expected this month from crops sown or planted on time earlier in the season.

Radicchio · Jun 25 – Aug 4Tarragon · Jul 2 – Aug 1Potato · Jul 5 – Aug 24Fennel (Bulb) · Jul 7 – Aug 1Mint · Jul 12 – Aug 1Lemon Balm · Jul 12 – Aug 1Cucumber · Jul 13 – Aug 2Tomato · Jul 16 – Aug 10Sweet Corn · Jul 16 – Aug 25Sweet Marjoram · Jul 16 – Aug 5Onion · Jul 18 – Aug 17Shallot · Jul 18 – Aug 17Bitter Melon · Jul 18 – Aug 7Malabar Spinach · Jul 18 – Aug 2Endive & Escarole · Jul 20 – Aug 4Bell Pepper · Jul 23 – Aug 22Southern Pea (Cowpea) · Jul 23 – Aug 22Thyme · Jul 24 – Aug 8Sage · Jul 24 – Aug 8Brussels Sprouts · Jul 25 – Aug 24Ground Cherry · Jul 26 – Aug 15Sunflower · Jul 26 – Aug 25Shiso (Perilla) · Jul 26 – Aug 15Lima Bean · Jul 28 – Aug 27Cucamelon · Jul 28 – Aug 7Oregano · Jul 29 – Aug 8Edamame (Soybean) · Jul 31 – Aug 25Tomatillo · Jul 31 – Aug 25Chili Pepper · Aug 2 – Sep 1Cantaloupe / Muskmelon · Aug 2 – Aug 22Watermelon · Aug 2 – Sep 1Eggplant · Aug 4 – Aug 24Leek · Aug 4 – Sep 23Winter Squash · Aug 5 – Sep 4Zucchini / Summer Squash · Aug 7 – Sep 8Parsnip · Aug 11 – Sep 10Salsify · Aug 14 – Sep 23Pumpkin · Aug 15 – Sep 14Broccoli · Aug 15 – Sep 26Cauliflower · Aug 15 – Oct 1Cabbage · Aug 15 – Oct 11Rosemary · Aug 15 – Sep 14Celery · Aug 18 – Sep 27Celeriac · Aug 18 – Sep 7Bush Bean · Aug 19 – Sep 15Kale · Aug 19 – Sep 20Lettuce · Aug 20 – Oct 6Luffa (Loofah Gourd) · Aug 22 – Oct 21Bok Choy / Pak Choi · Aug 25 – Sep 26Mizuna · Aug 25 – Sep 21Peanut · Aug 25 – Oct 14Swiss Chard · Aug 26 – Sep 22Napa Cabbage · Aug 26 – Oct 7Mustard Greens · Aug 27 – Sep 28Cilantro / Coriander · Aug 28 – Oct 9Carrot · Aug 29 – Oct 5Sweet Potato · Aug 29 – Sep 28Dill · Aug 30 – Oct 6Rapini (Broccoli Raab) · Aug 30 – Oct 6Pea · Aug 31 – Oct 2Collard Greens · Aug 31 – Oct 7

Fall garden season: August garden jobs in zone 4

  1. The average first frost is September 25, about 6 weeks away. Pick tender crops (tomatoes, peppers, squash, beans) before it, or cover them on cold nights.
  2. Still time to sow or plant: bok choy / pak choi, borage, dill, fava bean (broad bean), green onion / scallion, kohlrabi. Fast greens and radishes are the safest bets this late.
  3. Row cover buys 4-6°F of frost protection and weeks of extra harvest - see season extension.
  4. Pull finished crops and sow a cover crop (cereal rye or crimson clover) into empty beds before the soil gets cold.

Questions gardeners ask

What can I plant in zone 4 in August?

19 crops have a window in August: bok choy / pak choi, borage, dill, fava bean (broad bean), green onion / scallion, kohlrabi, lettuce, mache (corn salad), mizuna, rapini (broccoli raab) and more. The tables above give the exact dates for each.

When are the last and first frost in zone 4?

The typical last spring frost is around May 10 and the first fall frost around Sep 25. These are broad zone averages, so your own town can be a week or two either side: look yours up by ZIP code in the planting calendar.

What can I harvest in zone 4 in August?

From plantings made on time: radicchio, tarragon, potato, fennel (bulb), mint, lemon balm, cucumber, tomato, sweet corn, sweet marjoram.

August in states with land in zone 4

AlaskaArizonaColoradoIdahoIowaMaineMichiganMinnesotaMontanaNebraskaNevadaNew HampshireNew MexicoNew York

Zone 4 in other months

FebruaryMarchAprilMayJuneJulySeptemberOctoberZone 4 overview →

What to plant in August in other zones

Zone 3Zone 5Zone 6Zone 7Zone 8Zone 9Zone 10All states →

Dates are computed from the zone’s typical frost dates and each crop’s timing in our crop database. Your garden may be a week or two either side.