Mid-August: what to sow in Massachusetts

Mid-August is a change of strategy. Starting another long warm-season crop is usually a poor bet; warm soil and increasingly cool nights create a useful window for fast greens and roots.

Strong candidates

Crop Why it fits Main risk
Radishes Very short path to harvest Heat can reduce root quality
Arugula and mizuna Fast baby-leaf harvest Flea beetles and dry seedbeds
Spinach Improves as nights cool Hot soil can slow germination
Lettuce Useful as baby leaf or small heads Heat and uneven moisture
Bok choy Quick fall growth Heat stress or premature bolting
Turnips Greens and roots are both useful Crowding and late thinning
Beets Baby roots and greens reduce timing risk Full roots need more runway
Kale and collards Cold tolerance extends the season Slower than salad greens
Swiss chard Bridges warm and cool weather Large plants need space
Carrots Possible with quick cultivars Slow emergence and a tight window

Use Garden Today to compare the actual days before your first frost with each crop's maturity range.

The August seedbed

August sowing often fails from surface drying, not cold. Water the bed before sowing, cover seed at the proper depth, and keep the top layer consistently moist through emergence. Temporary shade cloth can help a hot seedbed, but remove or raise it as seedlings establish.

Sow short rows. Repeat fast crops in two or three weeks if the calendar and forecast still allow. A sequence of small plantings spreads both harvest and weather risk.

Add protection before it is urgent

Have hoops and row cover ready before the first cold night. Protection cannot replace missing weeks of growth, but it can keep an established fall crop useful longer.

Record sowing date, soil temperature, days to emergence, first thinning, first harvest, and the first night below 32°F. These observations are the beginning of your local fall calendar.