Rhubarb is a strange plant; it’s grown in the vegetable garden, eaten as a fruit, and possesses medicinal properties, which entitles it to be a herb. It is also fairly easy to grow, which makes it a good plant for gardeners who want to try something different. The best way to start growing rhubarb is by dividing the roots of established plants, which you may be able to do if you have friends or family who have plants. I am lucky in that my parents have always grown rhubarb. Small plants are also available from the herb stands in garden centres. It can be sown from seed, but it takes much longer for the plants to become established. It’s a tough plant and will thrive even in the face of a fair amount of neglect. It’s rarely troubled by insects and the only problem one can encounter is crown rot, which occurs if there is poor drainage.
Soil and position
As rhubarb is a perennial, the secret to healthy plants is to prepare the soil well before planting. It needs very fertile soil that drains well, and it responds well to organic feeding so prepare the bed by incorporating lots of compost and well-rotted manure. Raised or mounded beds will keep the soil aerated at root level. Your rhubarb bed needs a position in full sun.
Rhubarb roots can be planted in spring, from early September into October. Seeds should be sown where the plants will mature because seedlings don’t transplant easily. Space plants at least 1m apart to allow for good air circulation, which reduces the risk of fungal diseases. Plant the roots with the crown bud 5cm below the surface of the soil. Firm the soil down around the roots but keep it loose over the buds. Water the crown after planting.
Water well in hot dry weather and mulch the beds so that the soil remains moist.
Rhubarb responds best to organic liquid fertilisers.
The fungal disease crown rot can occur in very hot, humid conditions. The leaves wilt rapidly followed by rotting of the crown and roots. Remove the plant immediately and throw it away. The best preventive measure is to make sure that the bed drains well and is well aerated.
Allow the plants to grow into fairly substantial specimens before harvesting the stalks, otherwise they will lose their vigour. If conditions are right and the plant grows fast you could start harvesting within the first year, but if the plants are not large enough wait until the second year. Remove young, good-sized stalks (20mm thick) by turning and twisting. They can also be cut at ground level. Harvest about 2 – 3 stalks at a time from each plant. Remove the leaves (they are toxic) and put them on the compost heap. Flower stalks must be removed otherwise they drain away the strength of the plant. If you must pick the stalks before they are to be used, they can be stored for 2 – 4 weeks in the refrigerator. Stand the stalks in cold water for an hour or so to refresh them before cooking.
Rhubarb requires sweetening to reduce the extreme tartness, but first boil the stalks until they are tender and only then add the sugar. Sugar makes fruit hard so it should not be added at the beginning of cooking. Sweetened cooked rhubarb can be served as a sauce over ice cream, combined with fresh strawberries, or made into pies, tarts, puddings, breads, jam, jellies and refreshing beverages.