When to plant rhubarb in zone 4b — planting calendar

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Showing USDA Zone 4B

Growing SeasonZone 4b

Last frost ~May 15First frost ~Sep 25Today

Start indoorsTransplant / sowHarvestFrost risk

APRMAYJUNJULAUGSEPOCTNOVDECJANFEBMARAPRMAYJUNJULAUGSEPOCTNOV

Transplant May 1 · First harvest Oct 31 · Wrap by Sep 25

Last spring frostMay 15

Transplant outMay 1

First harvestOct 31

Last harvestSep 25

First fall frostSep 25

Why these dates work in zone 4b

Zone 4b's last spring frost averages May 15 and first fall frost Sep 25 — about 133 frost-free days. Rhubarb tolerates light frost, so you can set plants out ahead of the last-frost date and keep harvesting into the cooler fall.

Common questions

How long does rhubarb take to grow in zone 4b?

Rhubarb matures in about 548–730 days from transplanting. In zone 4b that means setting plants out around May 1 and first picking around Oct 31.

Will rhubarb survive frost in zone 4b?

Yes — rhubarb tolerates light frost. In zone 4b you can set plants out a little before the last frost (around May 15) and keep harvesting past the first fall frost (around Sep 25).

For soil, spacing, pests and companion planting, see the full rhubarb growing guide →