Plant Eggplant in Zone 9b

Zone 9b averages 298 frost-free days, running from a last spring frost around February 15 to a first fall frost around December 10. Eggplant needs roughly 85 days from planting out to first harvest, so it uses about 29 percent of that window. Eggplant is a tender crop, which is what decides where in the window it belongs.

Because eggplant needs a head start, sow seed indoors around Dec 21, about 8 weeks ahead of the Zone 9b last frost. Transplants go out around Mar 1. Starting earlier than that in Zone 9b usually backfires: plants outgrow their cells and stall when they finally hit cold soil. At 85 days to harvest, a 298-day Zone 9b season has room for about 3 sowings, so stagger them rather than planting everything at once.

Yes. Sow eggplant by August 19 in Zone 9b. That is 113 days before the average first frost, which covers the 85 days to maturity plus about two weeks for the slower growth that comes with shortening days, plus a two week margin because frost kills eggplant outright.

Eggplant needs a long warm run to finish, so a second planting is realistic only in zone 9 and warmer.