Rhubarb – Rhubarbum rhaponticum Perennial
A vegetable that is used as fruit. It is grown for its red edible leaf stalks and is always welcome as the first of the “fruits” to be harvested from the allotment. A bog plant it demands to be grown with plenty of moisture at the roots and its head in the sun.
Sow
Rhubarb plants grown from seed take 18 months before they are mature enough to harvest. Sow the seed during April either in 9cm / 3ins pots filled with fresh seed compost or outdoors in 25mm / 1 inch deep drills. Station sow the seed thinly along the drill before thinning down to one plant per station at 15cms /6 inch spacings. Allow the plants to grow before transplanting them to their permanent growing site in the autumn.
Grow on
It is better to buy in root divisions than to raise plants from seed. Seed raised plants always have the tendency to run to seed prematurely in the growing season. The roots can be planted during October / November or February/ March. Plant with the top of the crown bud about 5cms / 2 inches below the surface of the soil with 1metre / 1 yard between plants and rows. Do not pick in the first year to allow the rhubarb crown to build up for future seasons.
Aftercare
Water well in dry seasons especially when the plants are in production. Rhubarb is a hungry plant, cover all of the bed with well rotted manure or garden compost in the autumn or early spring. Top dress the rhubarb with a general fertiliser during July to help the plants recover for the next year.
Harvesting
Rhubarb can be harvested from March until late July; the cutting must stop to allow the plants to recover for next year. When harvesting the stalks hold them gently with both hands placing one above the other near the bottom of the stalk and gently pulling upwards. When ready the stalk will snap away without causing any damage to the rhubarb crown. The leaves are poisonous and must not be eaten in any form but they are safe to put on the compost heap.
Pests and diseases
Crown rot can cause rotting of the leaves and stalks. Collect and dispose of the leaves through the municipal waste system dig up and destroy the crown on the bonfire. Little else troubles rhubarb.