Cultivation notes
Any fertile garden soil can be used for rhubarb, as long as it is well drained and in full sun. Crowns (‘sets’) can be cropped for ten or more years, though division may be necessary after about five years.
Preparing the soil
Although the large foliage can help smother weeds, the ground should be free from perennial weeds before planting. Dig in one to two bucketfuls of well-rotted organic matter, such as manure, before planting.
Planting
Plant crowns in November or December. If necessary, planting can continue up to the beginning of March. Buy named cultivars, or choose a division from a strong, healthy-looking plant.
Plant the crown with the growing point at, or just below, the soil surface. On wetter soils, planting with the buds just raised out of the soil may help prevent rotting. If planting more than one crown, space plants 1m (3ft) apart, with 1-2m (3-6ft) between rows.
Expected yields range from 4½-13½kg (10-30lb) per 3m (10ft) row.
Cultivation
In hot summers, if the ground becomes dry, growth will slow down and even stop. A spring mulch of well-rotted organic matter 7cm (2½in) deep will help to retain moisture, but do not bury the crowns. Plants will also respond to watering during prolonged dry periods in summer. Apply a general fertiliser such as Growmore in spring or summer at 70g per sq m (2oz per square yard).
Allow the foliage to die back naturally in autumn, then cut away the old leaves to expose the growing points to winter cold. There is no harm in adding these leaves to the compost heap, as the poisonous oxalic acid contained in them breaks down during decomposition.
Rhubarb requires seven to nine weeks of cold weather below 3ºC (37ºF), depending on the cultivar.