Rainline Garden
When to plant rhubarb in Winthrop and Twisp, WA
Plant rhubarb crowns in Winthrop and Twisp Apr 3 – May 15.
- Difficulty
- Easy
- Sun
- Full sun to part shade
- Spacing
- 3 to 4 feet apart
- Planting depth
- Crown buds 1 to 2 inches below the surface
- Frost
- Hardy perennial; comes back every year
- First harvest
- Light picking in year two; full harvests from year three
Why these dates
Winthrop and Twisp's typical last spring frost is May 15. As a hardy perennial, this crop can go in about 6 weeks before that.
Inland Northwest. Higher, colder interior valleys. Cold springs and an earlier fall mean a shorter season; quick-maturing varieties pay off.
How to grow rhubarb in Winthrop and Twisp
- Pick a sunny spot with soil that drains well, and mix in an inch or two of compost.
- Plant rhubarb crowns Apr 3 – May 15, 3 to 4 feet apart. Crown buds 1 to 2 inches below the surface.
- Mulch with compost each spring, and cut off flower stalks as soon as they appear.
- Harvest: Pull (don't cut) stalks when they're 10 to 15 inches long. Take no more than a third at once, and stop in early summer. Never eat the leaves.
Key numbers
- 6.0–6.8Soil pH
- 10–15 inches longPull stalks at
- Every 5–10 yearsDivide
- Crown rot in wet soilBiggest risk
Growing notes
What makes the difference in Northwest gardens, in plain language.
Soil and feeding
Rhubarb is a hungry perennial that grows huge leaves every spring, so it rewards rich soil. Dig plenty of compost or aged manure into a wide area before planting, and spread a couple of inches of compost around the plant each spring, keeping it off the crown itself. Good drainage is essential: crowns rot in soggy winter soil, which is why west-side gardeners often plant on a low mound.
Rhubarb needs a cold winter to rest, which every part of the Northwest provides.
Harvest without weakening the plant
Pull stalks with a twist instead of cutting them, which leaves no stub to rot. Take no more than a third of the stalks at a time and stop in early summer, so the leaves that remain can rebuild the crown for next year. Thin, spindly stalks are a sign to stop sooner.
The leaves contain high levels of oxalic acid and are poisonous to eat, so cut them off and use only the stalks. Leaves are fine to put in the compost pile.
Care over the years
Cut flower stalks off at the base as soon as they appear; seed-making takes energy away from new leaves. Older plants flower more, and so do stressed ones.
After five to ten years, clumps get crowded and stalks get thinner. In early spring, just as buds swell, dig the crown and split it with a sharp spade into pieces that each have at least one or two buds and a good chunk of root. Replant them in fresh, enriched soil.
Common questions
When is the last frost in Winthrop and Twisp, WA?
Typically May 15. In 9 years out of 10, frost is over by June 1. These are 1991–2020 NOAA climate normals for Winthrop.
Is it too late to plant rhubarb in Winthrop and Twisp?
The spring planting window runs through May 15. Potted plants can still go in later if you water them faithfully through their first summer.
How long until I can pick rhubarb?
Light picking in year two; full harvests from year three. Pull (don't cut) stalks when they're 10 to 15 inches long. Take no more than a third at once, and stop in early summer. Never eat the leaves.
Why is my rhubarb flowering?
Mature plants flower naturally, and stress from heat, drought or poor soil makes it more likely. Cut the flower stalk off at the base right away. If a plant flowers heavily every year, it may be time to divide it.
Why are my rhubarb stalks green instead of red?
Color depends on the variety, not ripeness. Victoria is mostly green with red at the base, while Canada Red and Crimson Red are redder. Green stalks taste just as good, though they make paler pies and jam.
Can I put rhubarb leaves in my compost?
Yes. The oxalic acid that makes the leaves poisonous to eat breaks down during composting and doesn't harm the pile or your soil. Just don't feed them to people or animals.
Also plant in Winthrop and Twisp around the same time
Peas
Radishes
Spinach
Lettuce
Onions
Carrots
Beets
KalePlanting dates for rhubarb in nearby areas
- Wenatchee, WA Mar 20 – May 1
- Omak and Okanogan, WA Apr 1 – May 13
- Chelan, WA Mar 20 – May 1
- Leavenworth, WA Apr 1 – May 13
- Ellensburg, WA Apr 1 – May 13
- Spokane, WA Apr 1 – May 13
Full planting calendar for Winthrop and Twisp · Rhubarb in every city