Rhubarb is a perennial, coming up year after year. Rhubarb provides a large crop from a small space, and is harvested from May to August.
Biologically, rhubarb is an interesting plant:
• the fleshy stalks provide the food that we eat
• the leaves are poisonous, but have several uses
• the crown, rootstock, is actually an underground stem called a rhizome
• the flower is spectacular but should be removed as it weakens the plant
Suitable sites for rhubarb
• well drained soil. Rhubarb hates boggy conditions
• fertile soil – although this can be improved by adding farm yard manure
• open, sunny site
• avoid frost pockets
Where to grow rhubarb
• directly in the ground
• in raised beds
• in very large pots, at least 50cm deep and 50cm wide
How to plant rhubarb
Rhubarb crowns are planted in the winter when they are dormant.
• Add two bucket fulls /sq.meter of compost or well rotted farmyard manure to the soil, and dig it well in.
• Lay the crowns in the soil so that the tips of the crown are just showing above the soil.
• Crowns should be 80cm apart with 30cm between the rows.
How to Divide Rhubarb Crowns:
The time to divide or move rhubarb is in the autumn or spring when it is not growing.
• dig up the crowns (the fleshy rhizomes and buds)
• discard old or damaged parts of the crown
• use healthy bits of crown with 2-3 good buds on them
• prepare the ground with plenty of well rotted farmyard manure or compost ( rhubarb is very greedy)
• mulch the rhubarb crowns once planted
• be gentle with the young rhubarb plants in the first year, better not to force them, or to pull too many stalks
• therefore best to lift & divide a small section of the rhubarb bed each year, so there are always some older plants to force and use.
How to Force Rhubarb
* The rhubarb is ready to produce shoots in January.
* Force it up, by creating a dark environment.
* Cover it with a chimneypot, dustbin, or straw.
Forced rhubarb has long, tender, light coloured shoots which are good for pies and crumbles.
How to Look After Rhubarb
Rhubarb is really a spring crop. Rhubarb can be pulled all summer if it is growing vigorously, and if at least 25% of the stalks are left on the plant. When the stalks are no longer fat and juicy, but grow as thin stalks, the time has come to give it a rest.
The rhubarb plant should be kept weed free, so that it can grow and feed its roots. All damaged and discoloured leaves should be removed with their stalks.
In the autumn, rhubarb appreciates a good covering of well rotted farmyard manure.
When to Pull Rhubarb
Rhubarb is pulled from May to August.
Wait for the leaves to fully open, and choose the largest stalks.
Harvest the shoots when they are about 10inches long.
Insert a finger between the stalk and the bud, and gently push to the base of the bud before simultaneously twisting and pulling. This ensures that the whole stalk is removed. If part is left it will rot and spoil subsequent growth.
Rhubarb is really pulled, not picked! Rhubarb stalks must certainly not be cut with a knife as fungal diseases attack the plant through the cut.
Remember not to pick every stalk, leave some rhubarb to feed the root for next year.
Flowering rhubarb is a common site in the summer. If the rhubarb flower is left on the plant, the root will be weakened & the stalks will be weak and thin.
Some people like to see rhubarb flowers in the garden. But if you are after rhubarb for the kitchen, the rhubarb flowers should be removed as soon as the flower buds are seen.
To remove the flower stem:
• Hold the flowering-stalk close to the ground
• Pull upwards twisting the stalk
The tendency to bolting (flowering) depends on:
• variety – Victoria is more prone to flowering than other varieties
• maturity – older plants are more likely to flower than younger ones
• weather – prolonged high temperatures and drought promote flowering
• nutrition – lack of nutrients makes the plant want to seed
To encourage leaf growth and discourage flowering of rhubarb:
* divide the crowns every 4-5 years to keep them young
* water during the harvesting period if in drought conditions
* feed with well rotted manure or fertiliser in early spring and autumn
* do not totally strip the root – always leave 4 or 5 stalks.
* stop pulling stalks after July, to allow the leaves to feed the root
* do not force each crown more than once every two years
* provide an open, sunny site in the vegetable garden
Although flowering rhubarb looks pretty, it is not good for the production of rhubarb to eat.
The Rhubarb leaves are poisonous as they contain oxalic acid but they have many uses:
1. as a mulch to keep soil moist and prevent weed growth
2. as an organic pesticide
3. to brighten kitchen pans by boiling inside the pans
4. as a mould for a birdbath