Rhubarb (Rheum rhabarbarum)

Also known as: Garden rhubarb

Rhubarb (Rheum rhabarbarum) is a robust perennial that typically reaches a height of 2 to 4 feet (approximately 60 to 120 cm). The plant has large, heart-shaped leaves with thick, juicy stalks that can be either green or red and grow up to 18 inches (about 45 cm) long. The foliage dies back during winter. In summer, tall flower stalks emerge, bearing numerous small flowers that are white, yellow, or pinkish-green. The flowers give way to seed-bearing fruits that mature in the fall.

In This Article

Care Tips Water Sunlight Temperature Soil Fertilize Prune Propagation Repotting Toxicity

Attributes of Rhubarb

Lifespan

Perennial

Plant Type

Herb

Plant Height

1 m

Spread

2 m

Leaf Color

Green Red

Flower Size

1-2 inches

Flower Color

White Yellow Green

Images of Rhubarb

Quickly Identify Rhubarb

Large heart-shaped leaves with reddish petioles, reaching 2-3 feet (60-90 cm) in width and length.

Distinctive 3-winged, reddish-hued fruit for wind dispersal and seed protection.

Prominent leaf veins, especially central vein, with edible, thick reddish petioles.

Scientific Classification of Rhubarb

Phylum

Vascular plants

Class

Dicotyledons

Order

Caryophyllales

Family

Buckwheat

Genus

Rhubarbs

Species

Rhubarb

Planting and Growing of Rhubarb

Care Difficulty

Easy

Watering Schedule

Every 8 days

Sunlight Requirements

Full sun

Sunshine Duration

6-10 hours

Ideal Temperature

60-75℉

Soil Type

Potting Mix, Peat Mix

Soil pH

6.5-7.5

Fertilizer Type

Balanced

Pruning Season

Spring, Summer

Pruning Area

Branches, Leaves

Pruning Frequency

2 times a year

Repotting Season

Spring

Pot Type

Plastic, Ceramic

How to Water Rhubarb?

When it comes to watering Rheum rhabarbarum, aim for about 500 milliliters each time. The amount should be enough to moisten the soil thoroughly without leaving it waterlogged. Always check that the water penetrates down to the root level, but avoid any pooling on the surface to prevent root rot.

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What Are the Sunlight Requirements for Rhubarb?

Sunlight Requirements: Full sun, Partial sun

Duration of light: 6-8 hours daily

Rheum rhabarbarum benefits from full to partial sun, ideally receiving 6-8 hours of sunlight daily. This light exposure supports healthy stalk development and maximizes yield.

What is the best lighting for Rheum rhabarbarum? ›

How to ensure ideal lighting for Rheum rhabarbarum? ›

What benefits does ideal lighting provide to Rheum rhabarbarum? ›

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What Is the Ideal Temperature Range for Rhubarb?

Ideal Temperature: 60 ~ 75℉

The ideal temperature range for Rheum rhabarbarum, commonly known as rhubarb, is between 60°F and 75°F. These temperatures provide the optimal conditions for growth, encouraging healthy foliage and robust stalk development. Rhubarb thrives in cooler temperatures during the growing season, making these conditions ideal for its cultivation.

What Soil is Best for Rhubarb?

Soil type: Loam, Sandy loam, Clay soil

Soil PH: 6.5 ~ 7.5

Rheum rhabarbarum thrives in well-drained soil that prevents water from accumulating around the roots, which can lead to rot. This can be achieved by incorporating organic matter, which enhances drainage while providing nutrients. Rich organic soil is crucial for providing Rheum rhabarbarum with the nutrients it needs to grow. Compost or well-rotted manure enhances the soil's nutrient content, supporting robust leaf and stalk development. While good drainage is essential, the soil must also retain enough moisture to keep the plant hydrated during dry spells. Mulching the surface can help maintain soil moisture levels, benefiting plant health.

How to Fertilize Rhubarb?

Fertilizer type: Balanced

For optimal growth of Rheum rhabarbarum, apply about 2 tablespoons of a balanced 10-10-10 NPK fertilizer around the base of the plant during its active growth period. Avoid direct contact with the leaves to prevent burning.

How to Prune Rhubarb?

Pruning Time: Spring, Summer

Begin pruning Rheum rhabarbarum by removing any dead or damaged leaves. Use sharp, clean pruning shears to cut back the stalks to ground level in early spring. Throughout summer, continue to trim any yellowing or browning leaves to stimulate new growth and promote healthier foliage. To enhance the yield, focus on cutting the flower stalks as soon as they appear during spring. This diverts the plant’s energy towards the development of robust stalks. While harvesting, leave at least two-thirds of the plant to ensure regeneration and continuous production. More About Pruning Techniques→

How to Propagate Rhubarb plant?

Propagate Time: Spring, Early spring, Late spring

Ensure the soil is well-drained and rich in organic matter. Mix compost and well-aged manure to improve fertility and drainage before planting seeds or division pieces.

Plant rhubarb seeds 1/2 inch deep in seed trays. Maintain a consistent moisture level and sufficient warmth for germination, typically in a greenhouse or indoors.

Divide rhubarb crowns with a clean spade and ensure each section has a bud. Replant divisions in prepared soil, maintaining correct spacing for optimal growth.

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How to Repot Rhubarb plant?

Repotting frequency: Once every 2-3 years

Rheum rhabarbarum exhibits signals such as root crowding, slowed growth, or reduced vigor, indicating a need for repotting. Typically, repotting is ideal in spring or autumn, when the plant is less stressed and can adapt easily to the new environment.

Select a pot one size larger than the current pot, and ensure it has adequate drainage holes. This prevents waterlogging and promotes proper root growth, reducing the risk of root rot and enhancing plant health.

Opt for a well-draining, loamy soil mix. This soil type provides essential nutrients and ensures adequate aeration, which is crucial for preventing waterlogging and enhancing root development, ultimately supporting healthy foliage growth.

Toxicity of Rhubarb

Is Rhubarb toxic to cat?

Rhubarb is mildly toxic to cats, especially when they ingest its leaves. High quantities of rhubarb leaves can lead to poisoning in cats. After such exposure, affected felines might show symptoms of physical distress or illness, requiring urgent veterinary care. To protect the well-being of their feline friends, cat owners should keep a close watch on their pets and restrict their access to rhubarb. In case of accidental ingestion, seeking immediate treatment from a veterinarian is vital.

Is Rhubarb toxic to dog?

Rhubarb presents a modest toxicity concern for dogs. Although this plant is not extremely toxic, consuming substantial amounts, especially the leaves, can lead to poisoning. Dogs might find these parts of rhubarb appealing and may consume them, resulting in symptoms that signify poisoning. Pet owners should be vigilant that if their dog ingests a considerable quantity of rhubarb, they may notice signs such as gastrointestinal distress or other troubling symptoms. Should a dog consume rhubarb and display any negative reactions, it is crucial for the owner to seek prompt veterinary assistance to ensure the appropriate treatment and care of the dog's condition.

WARNING

The judgment on toxicity and danger is for reference only. We DO NOT GUARANTEE any accuracy of such judgment. Therefore, you SHALL NOT rely on such judgment. It is IMPORTANT TO SEEK PROFESSIONAL ADVICE in advance when necessary.

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