Rhubarb
- The Economic Botanist
- Jun 12
- 10 min read
Updated: Jun 13
Scientific name: Rheum rhabarbarum L.
Family: Polygonaceae
If you’ve ever enjoyed a slice of tangy rhubarb pie or savored a refreshing rhubarb compote, you’re already familiar with this unique plant. But rhubarb is much more than just a tasty treat—it has a fascinating history, interesting botanical features, and specific growing needs.
Whether you’re curious about how to grow rhubarb in your garden, want to learn about its health benefits, or just want to know how to safely handle it, you’re in the right place. If you’re new to rhubarb, you might find it a little intimidating at first because of its tart flavor and the fact that its leaves are poisonous. But once you get to know this plant, you’ll realize it’s a versatile, hardy, and rewarding addition to your garden or kitchen.
This Plant Compendium entry will cover everything you need to know about rhubarb—from its origins and growing tips to culinary uses and environmental impact.
Table of Contents
History of Rhubarb
Rhubarb’s story stretches back thousands of years, weaving through cultures and continents. Originally, rhubarb was valued primarily for its medicinal roots rather than its stalks. The plant’s wild ancestors grew in the cold mountainous regions of Siberia, Mongolia, and northern China. Ancient Chinese texts from around 2700 BCE mention rhubarb roots being used to treat digestive issues and other ailments.
The plant’s reputation as a medicine spread westward along the Silk Road. In medieval Europe, rhubarb was imported as a rare and expensive root—sometimes more precious than spices like cinnamon or pepper. Because it was so costly, only the wealthy could afford it for medicinal purposes.
Interestingly, the edible stalks we’re familiar with today didn’t become popular until the 1700s. Gardeners discovered that the tart stalks could be cooked like fruit and used in pies and jams, especially when combined with sweeter ingredients like strawberries. Since then, rhubarb has become a beloved crop in home gardens and commercial farms alike, especially in cooler climates where it thrives.
In the United States, rhubarb is sometimes called “pie plant” because of its traditional use in desserts. Fun fact: rhubarb has been cultivated in the UK since the 1600s and was once forced to grow in dark sheds to encourage early stalk production for the spring market.
Botanical Description
Rhubarb is a unique and resilient perennial plant prized for its thick, flavorful stalks and long-lasting presence in gardens. With its striking clusters of colorful petioles, large heart-shaped leaves, and tall flowering panicles, rhubarb offers a fascinating blend of form and function. From the nutrient-storing roots hidden beneath the soil to the rarely used seeds above, each part of the plant plays a vital role in its growth and survival. Understanding the characteristics of rhubarb’s stems, leaves, flowers, roots, and seeds helps gardeners appreciate both its beauty and its practical cultivation needs.
Stems: Rhubarb stalks, often called petioles, are thick, fleshy, and crisp. Their color can vary widely depending on the variety—from bright ruby red and deep pink to pale green. Some gardeners prefer red-stalked varieties for their sweeter taste, but green-stalked rhubarb is just as nutritious and flavorful. The stalks grow vertically in large clusters, and they can reach up to 18-24 inches tall in a growing season.
Leaves: The leaves are large, heart-shaped, and grow from the top of the stalk clusters. While they look inviting, it’s crucial to remember that rhubarb leaves contain high levels of oxalic acid and other toxins, which can cause poisoning if ingested. The leaves can measure up to 12 inches across and have a somewhat crinkled, rough texture.
Flowers: Rhubarb produces tall flower stalks—called panicles—that shoot up from the center of the plant in late spring or early summer. The flower clusters are made up of small, greenish-red flowers. Many gardeners recommend cutting flower stalks as soon as they appear because blooming can divert energy away from stalk growth, reducing your harvest.
Roots: Beneath the soil, rhubarb has thick, fleshy roots that form a crown. These crowns store energy for the plant and help it survive cold winters. The root system is vigorous and can live for decades with proper care. This perennial nature makes rhubarb a low-maintenance plant once established.
Seeds: Although rhubarb flowers can produce seeds, gardeners rarely propagate rhubarb from seeds because it takes several years to mature and may not produce true-to-type plants. Instead, the preferred method is crown division, which is quicker and more reliable.
Growing Instructions
Growing rhubarb is very rewarding, and once you get it going, it’s a perennial that keeps giving year after year. It’s a tough plant that tolerates cold winters but does have some specific needs to thrive. Let’s walk through everything you need to know to give your rhubarb the best start and keep it productive.
Here’s everything you need to know to get rhubarb off to a great start:
Sunlight: Rhubarb prefers full sun (at least six hours a day), which helps produce firm, flavorful stalks. However, it can tolerate some light shade, especially in hotter climates, to prevent the leaves from scorching.
Soil: Rich, fertile soil with good drainage is ideal. Rhubarb thrives in loamy or sandy soils amended with compost or well-rotted manure. A slightly acidic to neutral pH of 6.0–7.0 is best.
Temperature: Rhubarb loves cooler climates and needs a chilling period in winter to produce good growth in spring. It can survive temperatures as low as -20°F (-29°C) and is hardy in USDA zones 3–8.
Watering: Consistent moisture is important, especially during dry spells, but soggy soil can cause root rot. Water deeply once or twice a week, aiming for about an inch of water weekly.
Spacing: Plant crowns about 3 feet apart to allow room for the large leaves and stalks. Crowding can reduce airflow, increasing disease risk.
Pruning: Cut flower stalks as soon as they appear to maximize stalk growth. Remove any yellowing or damaged leaves to keep plants healthy and tidy.
Support: While mature rhubarb stalks are sturdy, heavy rains or wind can cause them to flop. If needed, you can stake the plant or use garden twine to support stalks.
Life Cycle: Rhubarb follows a typical life cycle consisting of:
Germination: Since rhubarb is usually propagated from crowns rather than seeds, germination isn’t common in-home gardens. When grown from seed, it can take up to two years to establish.
Vegetative Growth: In early spring, new shoots emerge from the crowns. Stalks grow rapidly through spring and early summer.
Flowering: Flower stalks typically appear in late spring. Many gardeners remove them to keep energy focused on leaf and stalk production.
Fruit Set: Rhubarb rarely produces edible fruit; seed pods develop but aren’t used for propagation.
End of Season: In late fall, the leaves die back as the plant enters dormancy for winter, conserving energy for the next season.
Harvesting and Foraging
Harvesting
Harvesting rhubarb at the right time is key to enjoying its best flavor and keeping the plant healthy for years to come. You should wait until your rhubarb plant is at least two years old before harvesting to allow the roots to establish.
The best harvesting season is from early spring through mid-summer, generally April to June, depending on your climate. You want the stalks to be firm, crisp, and at least 10–15 inches long. Stalks that are too thin may not have developed enough flavor.
To harvest, grasp the stalk near the base and pull it upward and slightly to the side with a gentle twisting motion. Avoid cutting with a knife because this can damage the crown and reduce future growth. After harvesting, leave at least one-third of the stalks on the plant to maintain its health.
Foraging
If you’re interested in wild or naturalized rhubarb, foraging can be a fun way to connect with nature, but caution is critical. Wild rhubarb usually grows in cooler regions and often near rivers or moist woodlands.
Be absolutely sure you’ve correctly identified rhubarb and not a toxic lookalike like dock or sorrel. Only harvest stalks, never the leaves, and don’t take too much from any one plant to ensure it can continue growing.
Foraging rhubarb can be rewarding, but it’s not a common practice, so always respect local regulations and the environment.
Plant Companions
Planting rhubarb alongside compatible companions can boost growth and reduce pests. Here are some excellent plant companions for rhubarb:
Strawberries: These are perhaps the best companions. Strawberries grow low and don’t compete for space, plus they benefit from the shade rhubarb leaves provide in warmer months.
Alliums (onions, garlic, chives): Their strong scents can deter pests that might bother rhubarb.
Brassicas (cabbage, broccoli, kale): These plants have similar soil needs and generally don’t compete aggressively with rhubarb.
Avoid planting rhubarb near potatoes or beans, as these may attract similar pests or compete for nutrients.
Common Pests and Diseases
While rhubarb is fairly pest-resistant, a few bugs and diseases can cause trouble:
Rhubarb Curculio: This small beetle lays eggs inside rhubarb stalks, causing holes and wilting. Remove and destroy affected stalks quickly.
Slugs and Snails: They love tender young leaves and can cause ragged damage. Barriers, traps, or hand-picking work well to control them.
Crown Rot: Usually caused by overly wet soil and poor drainage, this fungal disease rots the roots and crown. Improve soil drainage and avoid overwatering.
Leaf Spot: A fungal infection that causes small brown or reddish spots on leaves. Remove infected leaves to prevent spread.
Regular inspection and good garden hygiene can keep rhubarb healthy.
Shopping Tips
If you’re buying rhubarb for cooking or gardening, here are some pointers:
For Cooking: Choose stalks that are firm and have vibrant color—red stalks are often sweeter but green stalks are equally tasty. Avoid limp or bruised stalks. Fresh rhubarb is usually available in spring and early summer, but frozen rhubarb can be a convenient substitute off-season.
For Planting: Look for healthy, plump crowns with visible buds from a reputable nursery. Avoid crowns that look dry, shriveled, or moldy. Larger crowns tend to establish faster and produce more stalks.
Storage
Proper storage extends rhubarb’s freshness and flavor:
Refrigeration: Wrap stalks loosely in a plastic bag or damp paper towel and place in the crisper drawer. Use within 5–7 days for best texture.
Freezing: Wash and chop stalks into pieces, then freeze raw or blanched in airtight containers or freezer bags. Frozen rhubarb is perfect for cooking and baking.
Drying: Less common, but rhubarb can be dehydrated and ground into powder for teas or baking flavoring.
Culinary Uses
Rhubarb’s bright, tart flavor and crisp texture make it a unique and versatile ingredient that can transform a wide range of dishes—both sweet and savory. Its natural acidity brings a refreshing sharpness that balances sweetness, richness, or spice, making it a favorite for cooks who love bold flavors and creative combinations.
Pies and Crumbles: Rhubarb’s classic culinary role is in desserts, especially pies and crumbles. The stalks soften when cooked but maintain enough structure to provide a pleasant bite. Because rhubarb is quite tart on its own, it’s often paired with sweeter fruits like strawberries, raspberries, or apples, which mellow the sharpness and create a perfectly balanced filling. You can experiment with spice additions such as cinnamon, nutmeg, or ginger to deepen the flavor complexity. For a twist, try incorporating nuts or oats into the crumble topping for added texture.
Jams and Preserves: Cooking rhubarb down into jams or preserves concentrates its flavor and brings out a natural sweetness while keeping that characteristic tang. These spreads are perfect for slathering on toast, dolloping on yogurt, or using as a topping for pancakes or desserts. Rhubarb pairs well with complementary fruits such as ginger, orange, or vanilla in preserves, offering endless possibilities for homemade pantry staples. Its pectin content helps jams set nicely without needing much additional thickener.
Sauces and Chutneys: Rhubarb’s sharpness can brighten savory dishes, making it ideal for sauces and chutneys served alongside meats like pork, chicken, or duck. Its acidity cuts through fatty or rich flavors, adding freshness and complexity. To create a balanced chutney, combine rhubarb with ingredients like onions, garlic, mustard seeds, or dried fruits such as raisins or apricots. These condiments are excellent for elevating grilled or roasted dishes and can also be paired with cheeses or charcuterie boards.
Baked Goods: Incorporating rhubarb into baked goods such as muffins, cakes, scones, and quick breads adds moisture and a pleasantly tart zing. It pairs beautifully with warm spices like cinnamon, cardamom, or cloves and can be combined with other fruits like strawberries or blueberries for added sweetness. Rhubarb can be chopped and folded into batter or used as a layer or topping. For a fresh twist, try making a rhubarb glaze or compote to drizzle over your baked treats.
Drinks: Rhubarb’s bright acidity makes it an exciting flavor for beverages. Rhubarb syrup or cordial—made by simmering rhubarb with sugar and water—can be used to add a tangy, floral note to cocktails, lemonades, iced teas, or sparkling water. It works especially well in spring and summer drinks, lending a refreshing edge. Mix rhubarb syrup with gin, vodka, or sparkling wine for creative cocktails, or simply dilute it with soda water for a delicious non-alcoholic option.
Safety Tip: Always remember that while rhubarb stalks are delicious and nutritious, the leaves are toxic and must never be eaten. Be sure to discard all leaves before preparing rhubarb dishes to keep your meals safe and enjoyable. |
Health Benefits
Rhubarb is more than just a tasty treat—it’s a source of several health benefits:
Rich in Fiber: Supports digestion and regular bowel movements.
Packed with Antioxidants: Compounds like anthocyanins help fight inflammation and oxidative stress.
Good Source of Vitamins and Minerals: Particularly vitamin K, vitamin C, calcium, and manganese.
Low in Calories: Makes a great addition to weight management diets.
Traditional Medicine: Historically used as a mild laxative and digestive aid.
Toxicity and Safety
One of the most important things to know about rhubarb is that the leaves are poisonous. They contain oxalic acid and anthraquinone glycosides, which can cause serious health issues if eaten, including nausea, vomiting, difficulty breathing, and kidney damage.
Always discard rhubarb leaves and only eat the stalks. When handling rhubarb leaves, wash your hands afterward and clean any surfaces that came into contact with them. If you grow rhubarb at home, keep children and pets away from the leaves to avoid accidental ingestion.
Environmental Impact
Rhubarb is generally an environmentally friendly plant:
As a tough perennial, rhubarb develops deep, extensive roots that enhance soil health by improving aeration and increasing water retention. When its large leaves die back in autumn, they naturally decompose and act as mulch, enriching the soil with organic matter and promoting a thriving community of beneficial microbes.
Rhubarb’s low-maintenance nature and perennial growth cycle mean it requires less frequent soil disturbance compared to annual crops. This helps reduce soil erosion and lowers the need for fertilizers and pesticides—important aspects of sustainable and eco-friendly gardening.
Emerging early in spring, rhubarb provides valuable ground cover that suppresses competing weeds. Additionally, its deep roots not only improve soil structure but also access nutrients from deeper soil layers, making them available to surrounding plants.
Rhubarb can act as a natural pest deterrent, and its leaves, though toxic if eaten, can be composted or used to make organic pesticides—contributing to the self-sufficiency and ecological balance of a permaculture system.
Commercial rhubarb farming may sometimes involve pesticides and herbicides, so supporting sustainable practices benefits the environment.
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