How to grow rhubarb
Rheum rhabarbarum · Polygonaceae · Vegetable
When to plant rhubarb: the short answer
Plant out about 3 weeks before it. Seeds germinate in soil from 55 to 80°F, fastest near 70°F.
Zone 5: plant out Apr 2 – Apr 19. Zone 7: plant out Mar 8 – Mar 25. Zone 9: plant out Jan 23 – Feb 9. See every zone.
Rhubarb is a cool-season vegetable in the Polygonaceae family, usually started indoors and set out as transplants. It wants full sun, though it tolerates a little afternoon shade in hot regions and steady, even moisture. From sowing to first pick is about 365–730 days. It is one of the toughest crops here, standing through hard frost and often improving for it.
Grower’s note: A cold-loving perennial that needs winter dormancy - it struggles below about Zone 8. Plant dormant crowns with the bud just at soil level. Only the stalks are edible; the leaves are toxic. Take nothing the first year, a few stalks the second.
Sowing
Sow about 2″ deep, into soil between 55–80°F — germination is quickest near 70°F. It is slow and often erratic to germinate (14–21 days).
Spacing & layout
Give each plant about 36″ along the row with roughly 48″ between rows. On a square-foot grid that is one plant per 4 square feet. Allow at least 18″ of loose, workable soil for the roots. It needs more root room than most containers give and does best in the ground.
Fitting it to your season
Rhubarb is a perennial: you plant it once and it comes back and crops for years, so it does not fit the annual sow-and-harvest cycle. Give it a permanent, well-prepared spot out of the way of yearly digging. It takes one to three seasons to reach a full harvest — take little or nothing the first year while the plant establishes.
Quick facts
Growth stages: how long rhubarb takes to grow
From seed to first harvest takes roughly 55-107 weeks: about 3 weeks as a seedling indoors, then 365-730 days in the garden. It is a perennial, so once established it comes back and crops year after year.
When to plant rhubarb
When to plant rhubarb by USDA zone
Dates worked out from each zone’s typical frost dates for 2026. Find your zone on the zone map, or pick your state below for dates from its own frost dates. Zones 11 and above are frost-free, so timing there depends on heat and rain instead.
| Zone | Last / first frost | Start indoors | Sow or plant out |
|---|---|---|---|
| Zone 3 | May 15 / Sep 15 | - | Apr 17 – May 4 |
| Zone 4 | May 10 / Sep 25 | - | Apr 12 – Apr 29 |
| Zone 5 | Apr 30 / Oct 5 | - | Apr 2 – Apr 19 |
| Zone 6 | Apr 15 / Oct 15 | - | Mar 18 – Apr 4 |
| Zone 7 | Apr 5 / Oct 25 | - | Mar 8 – Mar 25 |
| Zone 8 | Mar 20 / Nov 5 | - | Feb 20 – Mar 9 |
| Zone 9 | Feb 20 / Nov 30 | - | Jan 23 – Feb 9 |
| Zone 10 | Jan 30 / Dec 15 | - | Jan 2 – Jan 19 |
Companions
Cabbage, Broccoli, Bush Bean
No strong antagonists recorded.
Common problems
Pests: rhubarb curculio, slugs.
Diseases & disorders: crown rot, leaf spot, ramularia leaf spot.
Same family (Polygonaceae)
Rotate these so they don’t follow each other in the same bed year to year.
Questions gardeners ask
When should I plant rhubarb?
Plant out about 3 weeks before it. Seeds germinate in soil from 55 to 80°F. The table on this page gives dates for each USDA zone, and the planting calendar gives dates for your own state or ZIP code.
How long does rhubarb take to grow?
About 365-730 days from transplanting to the first harvest, or roughly 55-107 weeks from sowing the seed indoors. Seeds germinate in 14-21 days.
How much sun does rhubarb need?
It needs six or more hours of sun for the best growth, though four to six hours in partial shade is enough.
What soil pH does rhubarb need?
A soil pH between 5.5 and 7.0. It tolerates fairly acidic soil better than most vegetables. Test before adding lime or sulfur - see the soil pH and testing guide.
How far apart should I plant rhubarb?
Space plants about 36 inches apart in rows 48 inches apart, or one plant per 4 square feet in a square-foot bed. Sow seeds about 2 inches deep.
Can I grow rhubarb in a container?
It is not well suited to containers - it needs more root room and space than a pot gives, so grow it in a bed.
Figures are typical home-garden ranges from Cooperative Extension planting guides, cross-checked against multiple state sources. Your variety and conditions will vary.