When to plant rhubarb in zone 4a — planting calendar

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Showing USDA Zone 4A

Growing SeasonZone 4a

Last frost ~May 20First frost ~Sep 20Today

Start indoorsTransplant / sowHarvestFrost risk

APRMAYJUNJULAUGSEPOCTNOVDECJANFEBMARAPRMAYJUNJULAUGSEPOCTNOV

Transplant May 6 · First harvest Nov 5 · Wrap by Sep 20

Last spring frostMay 20

Transplant outMay 6

First harvestNov 5

Last harvestSep 20

First fall frostSep 20

Why these dates work in zone 4a

Zone 4a's last spring frost averages May 20 and first fall frost Sep 20 — about 123 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 4a?

Rhubarb matures in about 548–730 days from transplanting. In zone 4a that means setting plants out around May 6 and first picking around Nov 5.

Will rhubarb survive frost in zone 4a?

Yes — rhubarb tolerates light frost. In zone 4a you can set plants out a little before the last frost (around May 20) and keep harvesting past the first fall frost (around Sep 20).

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