How to Grow Rhubarb Glaskin's Perpetual

Rhubarb Glaskin's Perpetual

Rheum rhabarbarum 'Glaskin's Perpetual'

vegetable

Glaskin's Perpetual is a vigorous rhubarb cultivar known for its ability to produce tender red stalks throughout the growing season, including summer harvests when standard varieties rest. This perennial grows 24-36 inches tall and produces slender, sweeter stalks with less oxalic acid than traditional varieties. It's prized for continuous harvesting and improved flavor compared to older rhubarb cultivars.

Growing Conditions

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Sun: Full sun, 6-8 hours daily; tolerates partial shade in warmer zones (4+ afternoon shade beneficial)

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Water: Keep soil consistently moist but not waterlogged; water 1-2 inches per week depending on rainfall. Mulch heavily to retain moisture and regulate soil temperature. More water needed during hot summers.

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Spacing: 36 inches

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Days to maturity: Year 2-3 for full production (can lightly harvest year 2)

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Planting depth: Crown should be 1-2 inches below soil surface; space crowns 36 inches apart

Soil

Type: Rich, well-draining loamy soil with high organic matter

pH: 6.0-6.8

Amendments:

Aged compost (2-3 inches worked in) Well-rotted manure Peat moss or leaf mold Balanced fertilizer (5-10-10)

Growing Zones

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Thrives in zones 3-7; performs well into zone 8 with afternoon shade

3a 3b 4a 4b 5a 5b 6a 6b 7a 7b 8a

Growth Stages

Establishment

Year 1

Young plants develop robust root systems and establish crowns; minimal stalk production expected

Remove all flower buds the first year to encourage root development. Water consistently. Apply 2-3 inches of mulch. Avoid harvesting in year 1.

Early Production

Year 2

Plants begin producing slender stalks; foliage becomes fuller and more vigorous

Light harvest allowed (2-3 weeks max) in late spring. Remove flower stalks as they emerge. Continue heavy mulching. Side-dress with compost.

Full Vegetative Growth

Year 3 onward, spring-summer

Large, deeply lobed leaves (12-24 inches) emerge from crown; multiple stalks develop continuously

Harvest regularly from mid-spring through summer to encourage continuous production. Remove any flower buds. Apply balanced fertilizer in early spring and after heavy harvest. Maintain consistent moisture.

Summer Production

June-August

Unique to Glaskin's Perpetual: stalks continue forming during summer months when traditional rhubarb goes dormant

Harvest stalks as they reach 8-12 inches. Provide afternoon shade in zones 7+. Consistent watering critical. Continue to remove flower buds.

Dormancy Preparation

September-March

Growth slows in fall; foliage begins to yellow and die back as plant prepares for winter

Stop harvesting by late August. Let foliage die back naturally. Apply 3-4 inches of mulch (compost or aged manure) for winter protection and spring nutrition. Do not cut back foliage until spring.

Companion Planting

Plan your garden →

Plant with:

Strawberry Garlic Onion Kale Lettuce Asparagus Borage

Avoid planting near:

Potatoes Tomatoes Melons Cucumbers Fennel Dock

Common Pests

Remove and destroy infested stalks. Use yellow sticky traps. Encourage beneficial insects. Remove plant debris in fall.
Hand-pick larvae from undersides of leaves. Spray neem oil or insecticidal soap in late spring. Maintain plant vigor through proper feeding and watering.
and
Remove mulch near plant base in early spring. Hand-pick in evening. Use beer traps or copper tape barriers. Remove excess moisture.
Spray leaves with water to dislodge. Use neem oil or miticide if severe. Ensure adequate humidity by watering foliage.
Ensure excellent drainage. Avoid overwatering. Plant crowns at proper depth (not too deep). Remove and destroy severely affected plants.

Uses

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Pies, Jams & Compotes

Culinary

Glaskin's Perpetual stalks have sweeter, more refined flavor than traditional varieties with reduced oxalic acid content, making them ideal for desserts, jams, and compotes. The slender stalks require less sugar when cooking. [source]

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Spring & Summer Cooking

Culinary

Because this cultivar produces throughout summer unlike standard rhubarb, it provides fresh stalks for cooking when other varieties are dormant, extending the harvest season significantly. [source]

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Traditional Remedy

Medicinal

Rhubarb root has been used in traditional Chinese medicine and Western herbalism as a gentle digestive aid and mild laxative due to its anthraquinone compounds (senna-like constituents). [source]

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Natural Dye & Cleaning

Household

Rhubarb roots and stalks can be used to create natural dyes (yellows and golds) and have been traditionally used as a gentle plant-based cleaning agent due to oxalic acid content. [source]

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Pollinator Support

Wildlife

When allowed to flower, rhubarb produces tall flower spikes attractive to bees and other pollinators, providing valuable early-season nectar. [source]

This is not medical advice. LizPlants is not a medical resource. Always consult a qualified healthcare professional before using plants medicinally.

Harvest Tips

Begin light harvesting in year 2 (2-3 weeks only). In year 3+, harvest from mid-April through August by grasping stalks at base and pulling sharply away from crown—do not cut with knife. Harvest stalks 8-12 inches long and ¾-1 inch diameter. Stop harvesting by late August to allow plant recovery. A mature plant can yield 2-3 pounds per harvest. Remove all flower buds as soon as they appear to maximize stalk production.

Fun Facts

🌱 Glaskin's Perpetual was developed in the 1950s by William Glaskin, an English gardener, specifically to overcome rhubarb's traditional dormancy period in summer heat.
🌱 This variety produces stalks with 30-40% less oxalic acid than standard rhubarb varieties, making it genuinely sweeter and safer for those concerned about oxalate intake.
🌱 Rhubarb is botanically a vegetable (leaf petiole) but legally classified as a fruit in the U.S. since 1947 due to its culinary use in sweet dishes—a famous ruling made to reduce tariffs on imported rhubarb.

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