Rhubarb is a familiar plant in British gardens and kitchens, loved for its tart stalks that make delicious crumbles, jams and pies. Its bold leaves and red or green stems are easily recognisable, and many people grow it as a reliable perennial crop. Yet despite its popularity, rhubarb carries an air of mystery and concern. Gardeners often ask whether the rhubarb plant is poisonous, and the answer is both straightforward and important for safe enjoyment.
Which parts of rhubarb are safe to eat
The edible part of the rhubarb plant is the stalk, sometimes called the petiole. These stems are safe, healthy and widely consumed once cooked. They are rich in fibre and contain vitamin C, potassium and antioxidants. Cooking reduces their sharp acidity and transforms them into a versatile ingredient for sweet and savoury dishes alike. However, the leaves of the rhubarb plant are not safe to eat. They contain substances that can be toxic to humans and animals, which is why the stalks are always separated from the leaves before use.
Why rhubarb leaves are poisonous
Rhubarb leaves contain high levels of oxalic acid, a naturally occurring compound also found in smaller amounts in foods such as spinach and beetroot. In high concentrations, oxalic acid can be harmful because it binds with calcium in the body, potentially leading to kidney stones or interfering with other essential processes. The leaves may also contain anthraquinone glycosides, compounds that irritate the digestive system. Together, these make rhubarb leaves unsafe for consumption. While a small accidental taste is unlikely to cause severe harm in most adults, larger quantities can lead to symptoms such as nausea, vomiting and stomach pain.
Are rhubarb stalks ever unsafe
The stalks themselves are safe to eat, but they should always be prepared properly. They are usually cooked with sugar or combined with sweet ingredients to balance their tartness. Raw rhubarb stalks are not harmful in small amounts, though they can be unpleasantly sour. One point of caution arises after a hard frost. When rhubarb plants experience severe cold, toxins from the leaves can migrate in small amounts into the stalks. These stalks should not be eaten, as they may cause mild poisoning. Gardeners usually cut away and discard any stalks affected by frost damage, allowing the plant to regrow safely.
The history of rhubarb use
Rhubarb has been grown for centuries both as a food and for medicinal purposes. In ancient China, it was valued for its roots, which were dried and used as a powerful purgative. It was later introduced to Europe, where its stems became prized for culinary use. In the eighteenth and nineteenth centuries, rhubarb became a popular dessert ingredient in Britain, often combined with sugar and custard. Despite its long history of safe use, the warnings about poisonous leaves have always accompanied its reputation, reminding cooks and gardeners to handle it correctly.
Recognising symptoms of rhubarb poisoning
If rhubarb leaves are consumed in large amounts, they can cause a range of symptoms. The oxalic acid can lead to burning sensations in the mouth and throat, difficulty breathing and gastrointestinal distress. In very rare cases of extreme ingestion, more serious complications such as kidney failure could occur. However, it would take a significant quantity of leaves to cause severe poisoning in an adult. Most accidental ingestion leads to mild symptoms such as stomach upset. Pets, especially cats and dogs, are more vulnerable to poisoning, and owners should ensure that rhubarb leaves are not left where animals can chew them.
Handling rhubarb safely in the garden
When harvesting rhubarb, always remove the leaves from the stalks immediately and discard them. Do not add them to compost heaps used for edible crops, as the toxins may persist. Instead, dispose of them in general waste or a dedicated compost heap for non edible garden waste. Always wash hands after handling rhubarb leaves, particularly before preparing food. By following these simple steps, you can ensure that only the safe stalks are used and there is no risk from the poisonous parts.
Cooking and storing rhubarb safely
Rhubarb stalks should be trimmed of any remaining leaf material before cooking. They can be stewed, baked, roasted or preserved, and freezing is also an excellent way to store them for later use. Cooking does not affect the safety of rhubarb stalks, but it enhances flavour and softens their texture. Because the leaves are the only toxic part, cooked dishes made solely from stalks pose no danger. Leftover rhubarb should be stored in the fridge and used within a few days or frozen for long term use.
Rhubarb in medicine and folklore
Beyond its culinary role, rhubarb has a long association with traditional medicine. The roots, not the leaves, were used historically as a strong laxative. This medicinal rhubarb was imported to Europe from Asia for centuries before local varieties were widely cultivated. Folklore around rhubarb often emphasised its dual nature as both food and medicine, and the dangers of its leaves were well known to past generations. Modern awareness continues this tradition, balancing enjoyment of the edible stalks with caution about the toxic parts.
Pets and rhubarb plants
Gardeners with pets should be particularly cautious. Cats and dogs may chew rhubarb leaves out of curiosity, and this can lead to poisoning. Symptoms in pets may include drooling, lethargy, loss of appetite and gastrointestinal distress. Veterinary care should be sought if an animal is suspected to have eaten rhubarb leaves. Fortunately, most pets do not find the leaves appealing, but the risk remains. It is best to fence off rhubarb patches or supervise pets in gardens where it is grown.
Myths and misunderstandings about rhubarb
One common myth is that the stalks of rhubarb are also poisonous. This is not true under normal conditions, as the stalks are safe and widely eaten. Another misunderstanding is that rhubarb leaves are deadly even in small amounts. While they should never be eaten, it usually takes a relatively large quantity to cause serious poisoning. These exaggerated fears sometimes discourage people from growing or enjoying rhubarb. In reality, with basic care and knowledge, rhubarb is a safe and rewarding crop.
Why rhubarb remains a popular crop
Despite concerns about toxicity, rhubarb continues to be a favourite in gardens and kitchens. Its resilience, ability to produce for many years and its distinct flavour make it invaluable. For many families, rhubarb is part of culinary tradition, linked to childhood memories of puddings and crumbles. By understanding which parts of the plant are safe and which are not, gardeners can enjoy abundant harvests without risk. Its popularity shows that knowledge and care are enough to overcome any dangers.
Conclusion
So, is the rhubarb plant poisonous? The answer is yes and no. The leaves are poisonous due to their high oxalic acid content and should never be eaten by humans or animals. The stalks, however, are perfectly safe and are the part we enjoy in countless recipes. By discarding the leaves, handling the plant carefully and being aware of frost damaged stalks, you can enjoy rhubarb with confidence. Rhubarb is a plant that rewards attention and care, offering delicious harvests while reminding us of the balance between beauty and danger in nature.
