In August, the mild-winter zones are when the fall garden shifts from intention to action. The heat is still heavy, but the starting gun has fired. Brassicas started indoors now — broccoli, cauliflower, cabbage, Brussels sprouts — will reach transplant size in 6–8 weeks, right as September temperatures begin to ease. Pansy, viola, and parsley also belong on the August indoor-start list if you want them for fall. At the same time, July brassica starts should be ready to harden off and move outside. Direct sowing remains limited this month, but carrots, collards, fava beans, and bunching onions can go in toward the end of August as soil temperatures begin to drop.
Indoors (fresh harvests):
- Microgreens: peas, broccoli, sunflowers, arugula
- Sprouts: alfalfa, broccoli, radish, mung
- Herbs & greens under lights: chives, parsley, mint
Start indoors now for fall transplant: broccoli, cauliflower, cabbage, Brussels sprouts, parsley, pansy, viola — started in August, these will be ready to go outside in late September and October.
Transplants to move outdoors (harden first): Brassicas started in July — broccoli, cabbage, cauliflower, kale, kohlrabi — are ready to harden off and go outside once daytime highs consistently drop below 90°F. Watch moisture closely during establishment.
Crops that can be directly sown outdoors in August: Fava bean (early August), California poppy, bachelor's buttons, sweet pea, carrot, collards, bunching onion (late August). For carrots, pre-germinating seeds in a cool spot before sowing significantly improves germination rates in warm soil.
Cover crops: Cowpeas, sunn hemp, sorghum-sudangrass — still effective through August.
Tip: An Olympia, WA zone 8 is very different from a Jackson, MS zone 8. Consider checking with your state Extension Service office for more specific recommendations and guidelines.
Use your USDA zone as a guide. Microclimates matter; coastal/urban spots run warmer; high-elevation spots run colder.
