Rhubarb is a perennial plant known for its long, celery-like stalks, which range in color from deep crimson to pale green. Despite being botanically a vegetable, it is almost exclusively used in cooking as a fruit, particularly in desserts. Its most distinctive feature is its intensely tart, sour flavor, which makes it a popular pairing with sweeter ingredients.
The stalks are the only edible part of the rhubarb plant — the leaves are actually toxic to humans and animals, containing high levels of oxalic acid. This is an important distinction, as the plant can look quite lush and inviting in the garden, but only the stems should ever be harvested and consumed.
In the kitchen, rhubarb is a classic ingredient in pies, crumbles, jams, and compotes. Its pairing with strawberries is perhaps the most beloved combination in Western baking, where the sweetness of the strawberry balances rhubarb’s sharp bite. It also works surprisingly well in savory dishes, chutneys, and even cocktails and shrubs.
Rhubarb thrives in cool climates and is a hardy, low-maintenance plant that returns year after year. It grows well in temperate regions of Europe, North America, and parts of Asia. In the UK, there is even a famous “Rhubarb Triangle” in Yorkshire, where forced rhubarb is grown in warm, dark sheds to produce tender, sweeter stalks during the winter months.
Nutritionally, rhubarb is low in calories and contains vitamin K, vitamin C, and some fiber. It has also been used in traditional Chinese medicine for centuries, primarily as a digestive aid. While it’s not a nutritional powerhouse on its own, its culinary versatility and uniquely bold flavor have earned it a devoted following among cooks and gardeners alike.
How To Grow And Care For Rhubarb
Choosing the Right Location
Rhubarb thrives best in a spot that receives full sun for at least six hours a day. While it can tolerate partial shade, more sunlight generally leads to stronger, more productive plants. Choose a permanent bed carefully, as rhubarb can remain in the same spot for up to 20 years.
Soil Preparation
Rhubarb prefers deep, fertile, well-draining soil with a slightly acidic to neutral pH, ideally between 6.0 and 6.8. Before planting, work the soil to a depth of at least 30cm and incorporate generous amounts of well-rotted compost or manure to enrich it. Good soil preparation at the start pays dividends for many years to come.
Planting Crowns vs. Seeds
Most gardeners plant rhubarb using crowns (root divisions) rather than seeds, as crowns produce harvests much faster — often within the first or second year. Seeds are slower and less predictable in terms of variety. Plant crowns in early spring or autumn, setting them just below the soil surface with the buds pointing upward.
Spacing and Depth
When planting, space each crown about 90cm to 1 meter apart, as rhubarb plants grow large and need room to spread. The crown bud should sit just at or slightly above soil level — planting too deep can cause the crown to rot. Adequate spacing also improves air circulation, reducing the risk of disease.
Watering Requirements
Rhubarb needs consistent moisture, especially during dry spells and in its first growing season when it is establishing its root system. Water deeply but avoid waterlogging, as rhubarb roots are susceptible to rot in overly wet conditions. Mulching around the base helps retain soil moisture between waterings.
Feeding and Fertilizing
Feed rhubarb with a balanced general-purpose fertilizer or a top dressing of well-rotted compost each spring as new growth begins to emerge. A high-potassium feed during the growing season can encourage stronger stalk development. Avoid over-feeding with nitrogen-heavy fertilizers, as this promotes leafy growth at the expense of the stalks.
Mulching
Applying a thick layer of mulch — such as straw, bark, or compost — around your rhubarb plants in spring and autumn offers multiple benefits. It suppresses weeds, retains moisture, regulates soil temperature, and adds nutrients as it breaks down. Keep the mulch slightly away from the crown itself to prevent moisture buildup that could lead to rot.
Managing Flowering and Bolting
Rhubarb occasionally sends up tall flower stalks, a process known as bolting. If this happens, remove the flower stalks immediately by cutting them at the base. Allowing the plant to flower diverts energy away from stalk production and can weaken the plant over time. Bolting is more common in hot weather or when plants are stressed.
Dividing and Propagating
Every five to ten years, rhubarb crowns benefit from being divided to maintain vigour and productivity. In early spring or autumn, dig up the entire crown and use a sharp spade to split it into sections, ensuring each piece has at least one healthy bud. Replant the divisions immediately in freshly prepared soil — this is also a great way to expand your rhubarb patch or share plants with others.
Forced Rhubarb
Forcing rhubarb is a technique that produces earlier, sweeter, and more tender stalks by excluding light from the plant. In late winter or very early spring, place a large pot, bucket, or traditional terracotta forcer over the crown to block out all light. The plant responds by shooting up rapidly in search of light, producing pale pink, delicate stems that are less bitter than outdoor-grown stalks.
Harvesting
In the first year of planting, resist the temptation to harvest any stalks at all, allowing the plant to put all its energy into establishing a strong root system. In the second year, harvest lightly — taking only two or three stalks per plant. From the third year onward, you can harvest more freely from spring through early summer by grasping the stalk near the base and pulling with a gentle twist.
How to Harvest Correctly
Always leave at least three to four stalks on the plant at any one time to ensure it can continue photosynthesizing and building energy reserves. Never harvest after midsummer, as the plant needs the latter part of the growing season to store energy in its roots for the following year. Cut off and discard the toxic leaves immediately after harvesting.
Winter Care and Dormancy
Rhubarb dies back completely in winter and enters a dormant phase, which is perfectly normal. Once the foliage has died down, clear away the old leaves and apply a generous mulch of compost or well-rotted manure over the crown area to protect the roots and feed the soil. The plant actually benefits from a cold winter period, as it needs a chilling period to break dormancy and produce well the following spring.
Pests and Diseases
Rhubarb is generally quite robust and resistant to many pests, but it can occasionally be affected by slugs, aphids, and vine weevils, particularly on young plants. Crown rot is the most serious disease and is usually caused by poor drainage or planting too deeply. Honey fungus can also be a problem — if affected, the crown should be removed and destroyed, and the soil replaced before replanting.
Common Mistakes to Avoid
Some of the most common mistakes with rhubarb include harvesting too heavily in the early years, failing to remove flower stalks, neglecting to divide old crowns, and planting in poorly drained soil. Patience is key with rhubarb — those who invest time in building a strong, well-fed plant in the first couple of years are rewarded with abundant, vigorous harvests for decades to come.