Plant Tomatoes in Zone 8b

Zone 8b averages 245 frost-free days, running from a last spring frost around March 15 to a first fall frost around November 15. Tomatoes needs roughly 75 days from planting out to first harvest, so it uses about 31 percent of that window. Tomatoes is a tender crop, which is what decides where in the window it belongs.

Because tomatoes needs a head start, sow seed indoors around Jan 25, about 7 weeks ahead of the Zone 8b last frost. Transplants go out around Mar 29. Starting earlier than that in Zone 8b usually backfires: plants outgrow their cells and stall when they finally hit cold soil. At 75 days to harvest, a 245-day Zone 8b season has room for about 2 sowings, so stagger them rather than planting everything at once.

Yes. Sow tomatoes by August 4 in Zone 8b. That is 103 days before the average first frost, which covers the 75 days to maturity plus about two weeks for the slower growth that comes with shortening days, plus a two week margin because frost kills tomatoes outright.

A second tomato crop only works where the first fall frost is late enough to finish it, which in practice means zone 9 and warmer.