Plant Cucumbers in Zone 6b

Zone 6b averages 186 frost-free days, running from a last spring frost around April 15 to a first fall frost around October 18. Cucumbers needs roughly 60 days from planting out to first harvest, so it uses about 32 percent of that window. Cucumbers is a tender crop, which is what decides where in the window it belongs.

Because cucumbers needs a head start, sow seed indoors around Mar 25, about 3 weeks ahead of the Zone 6b last frost. Transplants go out around Apr 29. Starting earlier than that in Zone 6b usually backfires: plants outgrow their cells and stall when they finally hit cold soil. At 60 days to harvest, a 186-day Zone 6b season has room for about 2 sowings, so stagger them rather than planting everything at once.

Yes. Sow cucumbers by July 22 in Zone 6b. That is 88 days before the average first frost, which covers the 60 days to maturity plus about two weeks for the slower growth that comes with shortening days, plus a two week margin because frost kills cucumbers outright.

A second sowing in midsummer usually dodges the worst of the cucumber beetle and powdery mildew pressure that kills the spring planting.