Rhubarb is certainly making a comeback in the kitchen and it is justified as it has to be one of the tasty and versatile vegetable around. Yes it is technically a vegetable not a fruit. Rhubarb is also an easy plant to grow; it really has few enemies, is remarkable hardy and it tolerates some neglect.
Rhubarb like plenty of sun and good drainage is essential as cold wet soil will cause the crown to rot. Prepare the ground by digging deeply to allow the roots to easily push in to the soil, apply plenty of compost and sheep pellets to the already dug over soil then dig that in lightly to the top 5cm, you can be generous with your compost it is impossible to over feed this plant.
Most Rhubarb plants are purchased already growing; one plant will equal one bud that will eventually develop in to the crown of a mature plant. They need space to grow as their foliage is dense and large, plant at half least metre spacing between each plant. Consideration also needs to be given to other plants in the garden as the foliage will over shadow and shade other vegetables in the garden.
Continue feeding through the growing season which depending on your region will be from spring through summer. Apply a liquid fertiliser every 10-14 days use a watering can. This will do double duty of giving the plant extra water during the summer months, water is essential to the production of juicy stalks. The plant will also benefit from a side dressing of blood and bone during the season, apply before watering. Feeding can stop once you have harvested the last of the stalks, usually as approaches and the plant will go dormant for the season.
Rhubarb will produce flower stalks, sometimes on young plants; flowering reduces the vigour of the plant and production of stalks, so remove this as you see them.
Rhubarb is hardy, but prolonged or an exceptionally hard frost will cause damage, remove the damaged leaves, keep a check on the crown and if any of the buds are damaged and don’t recover remove these as well, as they will rot. Protect the plant until the frosts are over.
Keep the base of the plant free of weeds free of weeds, to remove places for bugs to hide.
Leaf Spots are not serious, remove effected leaves. Spray with Copper Oxychloride if it becomes widespread.
Rhubarb mosaic is a light and dark mottling on the leaves; this can reduce the yield so remove the affected plant.
Unless you have exceptionally growth on your young plant, no stalks should be should be harvested for the first year, in the second year harvest very sparingly. This will the crown will mature fully and give you better results for longer.
Rhubarb as a rule of thumb will need dividing every 4-5 years, but I have seen plants produce for years and years. Let the plant be your guide, if the stalks are become thin and hollow then it is time to divide the plant. Dividing is done when the plant is dormant, usually around July/August for the winter dormant plants. Lift the whole plant crown system, shake away the soil so you can see the crown, the crown will consist of many individual buds. Each of these buds will develop into a plant, so using a sharp knife separate the buds cleanly. Remove any spindly roots and choose the strongest to replant. When you replant the bud no part of the bud should be showing above the ground, so cover to a depth of at least 2cm
Pull the Rhubarb when harvesting, select the stalk to be picked grasp the stalk down next to the base and at the same time as twisting the stalk off. This causes less damage to the crown than cutting the stalk does.
CAUTION: Rhubarb leaves contain high levels of Oxalic acid and should under no circumstances be used or eaten in any form. Once you have harvested the stalks remove the leaves and compost.