Harvest the fully grown outer stems of your rhubarb plants from the second year onward, pulling the largest stems from the outside of each plant as you need them.
Rheum × hybridum
This very attractive plant forms a clump of large, bold, dark green leaves up to 1 m (3 ft) high atop crimson red, edible leaf stalks. The red stalks become soft and succulent when cooked and have a naturally tart flavor, which most people sweeten with sugar or honey. Be warned, however, that the leaves are poisonous due to their oxalic acid content and should not be eaten.
Harvest the fully grown outer stems of your rhubarb plants from the second year onward, pulling the largest stems from the outside of each plant as you need them.
Rhubarb is easy to grow in rich, moist soil with plenty of organic matter, as long as it is well drained. If drainage is questionable, build up the bed first. It doesn’t like to dry out over summer, so grow it in semi-shade in hot, dry climates to avoid leaf scorch.
While rhubarb can be grown from seed, it is better to plant bare-rooted crowns, which are available in winter, or potted specimens. This will ensure that you grow a reliable variety and will take at least a year off the wait for your first crop. Space crowns 1 m (3 ft) apart. Don’t harvest the plant in its first year of growth. Instead, leave the crown to establish properly, and only start picking stalks in the second year. Crowns can remain productive for many years, although they should be divided, and some decline in vigor after five years should be expected. Remove any flower stems; they appear because of a lack of watering or fertilizing and will rob the crown of energy.
Problems The most common problem is crown rot, which causes the plants to suddenly collapse and die. Don’t replant in the same position, and make sure that soil drainage is excellent.
Harvesting Stalks should be around 2.5 cm (1 in) thick when harvested. Harvest only from the second year onward. Start from the outside of the clump, and don’t cut the stalks. Instead, pull down and twist, as this also removes the leaf collar from the crown.
There are a number of varieties available. Acidity varies, as does stem color, from green to deep burgundy red, but all have good flavor.
If the leaves are still attached to stalks, they should look fresh. Stalks should be vibrantly colored, firm, and plump, with no brown areas. To store, cut off the leaves and discard, then keep the stalks in a loosely sealed plastic bag in the crisper section of the refrigerator for up to a week.
Rhubarb root has been used in traditional Chinese medicine to treat constipation, diarrhea, digestive system ulcers, and high blood pressure. The roots and red stems contain tannins and anthraquinones—compounds that stimulate the intestines and act as a laxative. British researchers discovered that baking rhubarb for 20 minutes releases high levels of possible cancer-fighting polyphenols. Scientists are now hoping to use these results to study the effects that rhubarb’s antioxidants may play in treating leukemia.
Rhubarb root also contains lindleyin, a compound that may have hormone-like effects. In one preliminary study rhubarb extract seemed to ease the severity and frequency of menopausal hot flashes for 109 women; more research is needed to confirm that this use is safe and effective.
Rhubarb is best covered with foil and baked or simmered in a little water or fresh orange juice in a saucepan that has a tight-fitting lid. Never cook it in an aluminum container, as it will react and give a metallic taste.
Rhubarb and custard
Rhubarb and custard is an old-fashioned favorite that combines the silky tartness of rhubarb with the sweet creaminess of custard. If you’d like extra spice, you could add star anise, ginger, and grated citrus zest with the cinnamon.
Trim 1 bunch (500 g/1 lb) rhubarb and cut into pieces. Put 2/3 cup (160 g) sugar, 1 cinnamon stick, 1 tablespoon lemon or orange juice, and 2 tablespoons water in a medium saucepan. Stir over medium heat until the sugar dissolves, about 2 minutes. Reduce the heat to low. Add the rhubarb, cover, and simmer gently, stirring occasionally for 10 minutes, or until tender and not crunchy. Remove from the heat, discard the cinnamon stick, and set aside in a medium bowl, covered.
Put 100 g (3 1/2 oz) superfine sugar and 5 egg yolks in a medium bowl and beat with an electric mixer until light and fluffy.
Put 2 cups (500 ml) milk and 1 split vanilla bean in a heavy-bottomed saucepan and bring to a boil over medium heat. Pour it onto the egg mixture, whisking continuously to combine.
Pour the custard into a clean saucepan. Cook over low heat, stirring continuously, until it starts to thicken slightly.
Spoon a little custard over the rhubarb and transfer the remaining custard to a ceramic jug for serving.
Serves 4
Fruitful decision
Benjamin Franklin is credited with introducing rhubarb to North America in the 1770s, and although it failed to achieve immediate popularity, by the 1820s it had gained steady acceptance, largely as a pie filling. Although rhubarb is, botanically speaking, a vegetable, its use as a fruit led to a New York court ruling in 1947 that it was a fruit and should be taxed accordingly. At the time, taxes were lower for fruits than for vegetables in the U.S. This resulted in reduced prices for rhubarb, which led to an increase in both its availability and consumption. Shown here is Rhubarb by Norwegian artist Nikolai Astrup (1880–1928).
