How to Plant, Mulch, Harvest & Divide Rhubarb — Everything You Need to Know
Rhubarb is one of the most rewarding plants you can grow. It comes back every spring without replanting, survives frost, tolerates partial shade, and will keep producing for 10 to 20 years with minimal attention.
This guide answers every key question about rhubarb plants: how to mulch correctly, how to cut and harvest stalks, what to do with the leaves, when rhubarb is ripe, and how to divide crowns in fall.
Key Fact: Rhubarb is technically a vegetable, but it is used as a fruit in cooking. Only the stalks are edible — the leaves contain high levels of oxalic acid and are toxic to humans and animals.
What Are Rhubarb Plants and Why Should You Grow Them?
Rhubarb (Rheum rhabarbarum) is a cold-hardy perennial vegetable that produces thick, tart stalks each spring.
A well-sited rhubarb crown, planted once and cared for correctly, will be productive for two decades.
- Victoria — Green stalks, vigorous growth
- Crimson Red — Deep red, sweet-tart flavour
- Glaskin's Perpetual — Mild and early variety
Mulching Rhubarb Plants: The Right Way and Why It Matters
Mulching protects the crown through winter, retains moisture in summer, suppresses weeds, and improves soil quality.
When Should You Mulch Rhubarb?
Spring Mulching
Apply a 2–3 inch layer of well-rotted compost or aged manure around the base after new growth appears.
Winter Mulching
After the ground freezes in autumn, cover the crown with 2–4 inches of straw, compost, or leaf mulch.
Important: Never bury the crown. Keep the growing point exposed to avoid crown rot.
Best Mulch for Rhubarb
- Well-rotted compost
- Aged manure
- Straw
- Shredded leaves
- Bark chips
Can You Mulch Rhubarb with Wood Chips?
Yes, wood chips can be used around rhubarb plants. They suppress weeds and help retain moisture, but they should be paired with fertilizer or compost because they contain few nutrients.
Avoid wood chips from black walnut, eucalyptus, or cedar trees.
Warning: Never use plastic sheeting around rhubarb plants because it traps moisture and increases the risk of crown rot.
Rhubarb Leaves: Uses and Benefits
Rhubarb leaves are toxic to eat, but they still have several useful purposes in the garden.
Dried Rhubarb Leaf Uses
1. Mulch Between Garden Rows
Large rhubarb leaves can be used as temporary mulch to suppress weeds and hold moisture.
2. Compost Material
Rhubarb leaves are safe to compost because oxalic acid breaks down naturally during decomposition.
3. Natural Pest Spray
Boiled rhubarb leaves can create an organic spray that helps deter aphids and caterpillars.
4. Fabric Dye Mordant
The oxalic acid in rhubarb leaves can help natural dyes bond to fabric fibres.
How to Harvest Rhubarb Stalks Correctly
How to Cut Rhubarb the Right Way
- Wait until stalks are 10–18 inches long.
- Grip the stalk near the base.
- Pull gently upward while twisting slightly.
- The stalk should release cleanly from the crown.
- Remove and discard the leaf.
Do not cut stalks with a knife because leftover stubs can reduce future production.
When Is Rhubarb Ripe?
Rhubarb can be ripe even when green. Stalk colour depends on the variety, not ripeness.
Harvest when stalks are firm and 10–18 inches long.
How Many Stalks Should You Harvest?
Never harvest more than one-third to one-half of the plant at one time.
- Year 1 — Harvest nothing
- Year 2 — Harvest 2–3 stalks only
- Year 3 onward — Full harvest season
Can You Divide Rhubarb in the Fall?
Yes, rhubarb can be divided in fall after the plant becomes dormant.
However, early spring is usually the best time because the roots establish faster.
How to Divide Rhubarb Plants
- Dig around the entire crown.
- Lift the plant carefully.
- Cut the crown into sections.
- Ensure each piece has one healthy bud and roots.
- Discard diseased sections.
- Replant immediately.
- Water thoroughly and mulch lightly.
Avoid harvesting from newly divided plants for at least one full growing season.
Year-Round Rhubarb Care Calendar
Spring
- Remove winter mulch
- Apply fertilizer
- Add compost around crowns
- Remove flower stalks
Summer
- Water during dry weather
- Maintain mulch
- Stop harvesting by early July
Autumn
- Remove dead debris
- Apply winter mulch
- Divide crowns if needed
Winter
- No active care required
- Plan new beds and order crowns
Final Thoughts
Rhubarb is one of the best long-term investments for any garden. With correct mulching, harvesting, and division, a single plant can remain productive for decades.
The keys are simple:
- Mulch correctly
- Harvest using the pull-and-twist method
- Stop harvesting by midsummer
- Divide every 5–10 years
- Never let the plant go to seed
Follow these steps and your rhubarb plants can thrive for many years.
Kitchen Tip: Freeze chopped rhubarb until strawberries are ready, then combine them for classic strawberry rhubarb pie or jam.
