A jewel in the crown for flavour
Rhubarb is unique: it is a vegetable (a leaf stalk) that’s most often used in desserts – you can even dip the stalks in sugar and eat them raw. It’s also a herbaceous perennial, dying down in autumn only to bounce back with incredible vigour in the spring. And it can be forced to produce sweeter and more succulent sticks by covering it with a terracotta forcing pot or a dustbin in January.
For the best flavour, it’s worth investing in a named variety of rhubarb as it will give you years of eating. Which? Gardening tested 11 varieties to find the best flavoured – for results, see far right.
How to grow rhubarb
The best time to plant rhubarb crowns is from November to December when they are dormant, but you can wait until spring.
Rhubarb grows best in a sunny spot with rich, moist soil that doesn’t waterlog.
Give it at least one metre to spread, and dig in plenty of well-rotted manure or garden compost.
Plant the crown with the top bud just below the surface. Apply a balanced fertiliser, such as Growmore, each March, followed by a nitrogen fertiliser, such as dried blood or sulphate of ammonia, in June.
Mulch with garden compost or well-rotted manure in autumn.
You can propagate large clumps by chopping off younger pieces from the outside with a spade. Pieces that have a couple of healthy buds should produce a vigorous new clump in no time. Replace older clumps as they start to lose vigour.
Rhubarb is usually sold as a crown – the underground part of a one or two-year-old plant that survives over winter. It should have a couple of healthy buds. You’ll find a limited choice of varieties in garden centres. If you want unusual varieties, including the Best Buys, you’ll have to buy by mail order. Crowns cost about £10-£12 for three. It’s best to wait until the second year before harvesting.
Thompson & Morgan also sells “budded pieces” – a single healthy bud with a small piece of a larger crown – especially of more unusual varieties. They cost about £10 for two. These might take longer to establish, so you can’t expect a crop until the second spring.
You can buy potted plants, but this is the most expensive option, up to £22.99 for a three-litre pot. Finally, you can grow rhubarb from seed, and ‘Glaskin’s Perpetual’ is a good choice. However, this was one of the pooresttasting varieties in the taste test.
Rhubarb in flower
Rhubarb plants occasionally throw up large flower spikes. These are spectacular and would not be out of place in a large herbaceous border. Unfortunately, flowering weakens the plant and greatly reduces cropping. Cut off the flower stalks or discard the centre of an old clump – or propagate as described above.
How to force
Get an even earlier crop by covering the clump with a terracotta forcing pot or a plastic dustbin in January to exclude all light. The crowns need a cold period followed by a frost-free period in the dark to produce a flush of pale, succulent stalks. If you force a plant, give it a year to recover before forcing again.
How to harvest
From April onwards, pull the stalks rather than cut them. You’ll find they detach easily without leaving a stump to rot. Discard the leaves as they are poisonous. Always leave three or four strong stems and keep pulling the young tender ones. You should stop picking in late June to allow the plant to recover and build up reserves for the next year.
The National Collection of rhubarb is at RHS Garden Wisley (rhs.org.uk)
Clumber Park in Nottinghamshire runs a Rhubarb Event in May, with tastings and cookery demos (nationaltrust.org.uk/ clumber-park)
Where to buy
Ashridge Nurseries (01963 359444; ashridgetrees.co.uk), Chris Bowers (01366 388752; chrisbowers.co.uk), Crocus (08445 572233; crocus.co.uk), DT Brown (0845 371 0532; dtbrownseeds.co.uk); Marshalls Seeds (0844 557 6700; marshallsseeds.co.uk); Mr Fothergill’s (0845 371 0518; mr-fothergills.co.uk); Thompson & Morgan (0844 517 1818; thompson-morgan.com); Unwins (0844 573 8400; unwins.co.uk)
Dark arts: A terracotta forcer has been used to produce some delicious early stems of ‘Victoria’