What to plant in August in the Northeast and Midwest

Worked out for 67 cities from their own weather and frost dates, by zone.

What to sow and plant in August in the Northeast and Midwest, by zone: frost-free, highs above 82 °F (New York, Philadelphia and 25 more): zucchini, green beans, sweet corn, corn and Napa cabbage; frost-free, highs of 72–82 °F (Chicago, Boston and 38 more): zucchini, green beans, sweet corn, corn and Napa cabbage.

In the Northeast and Midwest, August is summer.

Frost-free, highs above 82 °F: New York, Philadelphia, Kansas City, St. Louis and 23 more

In August, on average, these cities have highs of 83 to 89 °F and lows of 61 to 71 °F, 1.5 to 5.6 in of rain on 7 to 13 days; the day lasts 13 h 37 min to 14 h 04 min (on the 15th).

No frost in August in 10 years of data: frost-tender crops can go in too, if it is warm enough for them.

How	What	Where
sow direct	Zucchini, green beans	New York, Philadelphia, Kansas City and 14 more
sow direct	Pumpkin, bok choy, borage, chayote, Florence fennel, kiwano, luffa, moringa, peanut, soybean	New York
sow direct	Sweet Corn, corn, Napa cabbage	New York, Philadelphia, Kansas City and 13 more

Compared with July: no longer sown — cucumber, watermelon, basil, achocha and okra.

Not starting in August: tomato (March, started indoors), bell pepper (March, started indoors), lettuce (April, sown direct), peas (April, sown direct) and spinach (no month outdoors by these rules) — dates for Omaha.

Ready to harvest in August in Omaha, if sown in the right month: zucchini (June), green beans (June), sweet corn (May), basil (June), bok choy (June), borage (June), corn (May) and Florence fennel (May).

Frost-free, highs of 72–82 °F: Chicago, Boston, Minneapolis, Detroit and 36 more

In August, on average, these cities have highs of 76 to 82 °F and lows of 58 to 71 °F, 2.4 to 5.2 in of rain on 8 to 15 days; the day lasts 13 h 45 min to 14 h 20 min (on the 15th).

No frost in August in 10 years of data: frost-tender crops can go in too, if it is warm enough for them.

How	What	Where
sow direct	Broad bean, arugula, chickpea	Cleveland, Buffalo, Rochester and 14 more
sow direct	Peas, cabbage, beet, mustard greens	Cleveland, Buffalo, Rochester and 12 more
plant sets	Onion	Cleveland, Buffalo, Rochester and 8 more
start indoors, plant out in September	Lettuce	Cleveland, Buffalo, Rochester and 8 more
start indoors, plant out in September	Cauliflower, kale	Cleveland
start indoors, plant out in September	Swiss Chard, kohlrabi	Cleveland and Erie
sow direct	Zucchini, green beans	Chicago, Boston, Detroit and 25 more
sow direct	Pumpkin, bok choy, borage, chayote, Florence fennel, kiwano, moringa, peanut, soybean	Cleveland, Atlantic City and Erie
sow direct	Sweet Corn, corn	Chicago, Boston, Detroit and 24 more
sow direct	Parsley	Cleveland, Buffalo, Rochester and 8 more
sow direct	Napa cabbage	Chicago, Boston, Detroit and 21 more
plant sets	Shallot	Cleveland, Buffalo, Rochester and 14 more
sow direct	Luffa	Cleveland and Atlantic City

Compared with July: new — lettuce, Swiss chard, kohlrabi and kale; no longer sown — broccoli, cucumber, watermelon, cilantro, basil, okra, achocha, chamomile and 1 more.

Not starting in August: tomato (March, started indoors), bell pepper (March, started indoors) and spinach (February, started indoors) — dates for Boston.

Ready to harvest in August in Boston, if sown in the right month: cabbage (April), zucchini (June), green beans (June), sweet corn (May), basil (June), bok choy (June), borage (June) and corn (May).

How we work it out

For each city we use its average weather in August and the months after (highs, lows and rain for 2016–2025, ERA5 reanalysis via Open-Meteo) and its average frost dates. A crop starts in August if the month's mean temperature reaches the minimum soil temperature for germination on its card (we use the mean air temperature as a stand-in for the soil's) and if, over its first months (up to three), the average highs stay within its group's range, with no frost for crops that cannot take it. Crops started indoors count from the month they are planted out.

Temperature groups from Colorado State University Extension: cool-season crops prefer 60–80 °F and lose quality in heat; hardy ones grow in days as cool as 40 °F, semi-hardy ones from 40–50 °F (we use 50 °F); warm-season crops need days above 55 °F, and the most tender (tomato, pepper, eggplant, melon, watermelon, squash) above 60 °F, up to 95 °F. Crops the guide does not name go into the stricter group by their frost hardiness. Fava (broad) beans, which the guide does not name, count as hardy: hardy varieties are sown in fall and overwinter (RHS). Garlic and bulbs: a month before the first frost, and later only while the ground is not frozen (as on each city's page).

Cornell Cooperative Extension sets the season here: hardy crops from about four weeks before the last frost, warm ones after it, heat lovers about 18 days after; the last plantings from 3 weeks (radish) to 16 weeks (melons) before the first frost — counted from each city’s own frost dates.

This is a general rule from averages: your garden can be a week or two earlier or later, and a greenhouse or a cold frame brings the season forward. Greenly works out the dates for your location.

What to plant in August in the Northeast and Midwest

Frost-free, highs above 82 °F: New York, Philadelphia, Kansas City, St. Louis and 23 more

Frost-free, highs of 72–82 °F: Chicago, Boston, Minneapolis, Detroit and 36 more

How we work it out

Other months in the Northeast and Midwest