What to Plant in September in Zone 7

Fava Beans Are the Real Planting This Month

Fava beans are the crop that actually goes into open ground now, settling in to overwinter and resuming growth once days lengthen again next spring rather than racing this fall's frost for a harvest. Sow the seed 2 inches deep and 6 inches apart in a bed that drains well; a fava stand sitting in standing water over winter rots before it ever gets the chance to overwinter.

Once established, fava plants shrug off a frost down into the low 20s without any cover at all, one of the hardiest legumes a home garden here can grow through winter. Figure on roughly 200 days total from this sowing to a spring harvest, most of that stretch spent simply holding steady underground rather than actively growing.

Garlic is not part of this month's planting here, only the work that gets its bed ready. Work a 2 to 3 inch layer of compost into that bed and rake it smooth, but leave the cloves themselves in storage rather than breaking a bulb apart early. Keep them in a paper bag somewhere cool and dark, since cloves left on a warm counter can sprout weeks before there is anywhere for them to go. Test the ground before you get impatient: press a thumb an inch or two into the bed, and if it still feels warm rather than cool, the soil has not caught up with the calendar yet. Cloves set into ground still holding onto summer's warmth push top growth now that a hard freeze cuts right back down come winter, a setback that shows up as a noticeably undersized bulb the following July.

The Last Fast Window Closes

Nearly everything else on this month's table is a last chance rather than a fresh start: cilantro, parsley, spinach, kale, chard, collards, mustard, radish, turnip, and a long list of Asian greens all need to go in during the first half of the month to have a real shot at maturing before your late-October frost.

The rule of thumb is simple, count the days a crop needs to mature and subtract them from the date of your first fall frost; anything needing more than about 55 days should already be a transplant, not a seed, by the middle of this month.

Cilantro sown now tends to hold longer before bolting than a spring sowing does, since cooling nights slow the flowering trigger that heat speeds up back in April and May. Expect 3 to 4 weeks of cutting rather than the single flush a hot-season planting gives.

Bok choy and tatsoi both size up fast in September's milder days, often ready to cut in as few as 30 days from seed. Either makes a reliable fallback for any bed that opens up unexpectedly once a summer crop finishes.

Watch soil moisture closely for anything direct-sown this month. Air feels cooler, but soil at a 1-inch depth can still dry out within a day if you skip watering, and shallow-planted seed simply won't germinate in dry soil.