Rhubarb illustration

Growing Rhubarb in Zone 3a

Zone 3a has harsh winters and a short growing season. Start Rhubarb early indoors to maximize your harvest window. Last frost: May 22. First frost: Sep 12.

Planting Calendar

Indoor
Outdoor
Harvest
Mar 13Sep 12

Season: May 22 – Sep 12 (113 days)

Zone3a
Last FrostMay 22
First FrostSep 12
Season Length113 days
Days to Harvest90
SunFull Sun
Frost ToleranceHeavy
Spacing1/sqft (12" apart)

When to Plant Rhubarb in Zone 3a

Start Seeds Indoors: Mar 13

Start Rhubarb seeds indoors around Mar 13 (10 weeks before last frost). Optimal germination temperature: 65°F. Germinates in 7–21 days.

Transplant Outdoors: Apr 24

Transplant Rhubarb seedlings outdoors after Apr 24. Wait until soil temperature reaches 40°F. Space plants at 1/sqft (12" apart). Harden off plants for a week before moving outside.

Harvest: Apr 24

First harvest approximately Apr 24 (~365 days from transplant). Continue harvesting until first frost (Sep 12). Rhubarb can overwinter in mild climates for continued harvest.

Plan Your Rhubarb Garden

Track Rhubarb from seed to harvest with personalized frost dates, watering recommendations, and companion planting visualization.

Start Free Rhubarb Growing Guide