Rhubarb seems to be one of those plants that gardeners either love or hate. I fall in the former category. I could go on about how I appreciate the plant for its ornamental qualities, what with its big bold leaves and stunning red stems, but I’d be only half telling the truth. In reality, the reason I love rhubarb is simple – it’s the key ingredient, alongside apples, in one of my favourite desserts.
Rhubarb’s eating qualities were actually discovered quite recently. For a couple of thousand years, the plant was cultivated solely for its medicinal qualities. Chinese herbalists used the root of wild rhubarb as a purgative, and Marco Polo wrote about the plant in the accounts of his travels through China. Not until 1778 did people learn that they could cook, and eat, the plant’s stems.
The rhubarb that we grow in our gardens is commonly thought to be a hybrid, Rheum x hybridum, and a number of cultivars are commonly available at this time of the year. ‘Ever Red’ is one of the best for smallish gardens or pots. It forms a compact plant with deep burgundy stems that are produced over an extended harvest period. Another old favourite is ‘Glaskin’s Perpetual’, a more vigorous plant with red to green stems. Not all rhubarbs are red though, and ‘Victoria’ is an old green variety that tastes just as good. In my garden I grow a local strain called ‘Highfields Ever Red’
Because it hails from northwestern China, Mongolia, Siberia and Tibet, rhubarb needs a cold winter to break dormancy. Temperatures below about five degrees Celsius will get the plant growing strongly in spring, but there’s a catch – rhubarb also prefers coolish summers. Grown in full sun, dry soil, and a hot climate, rhubarb will wilt quicker than an iceblock in the Sahara. My plants are tucked in to a sheltered border of the vegetable patch where they receive morning sun, but benefit from a full afternoon of shade in summer. Still, I find that on warm days deep watering a few times per week might be needed to keep the moisture in those big parasol leaves.
While rhubarb loves a reliable supply of moisture, the crown will quickly rot if conditions become waterlogged. So in addition to a rich soil, a must for growing great rhubarb is drainage. Work in plenty of organic matter such as rotted manure or compost prior to planting, but if your soil is heavy black clay, try using raised beds. If you’re still having trouble, consider planting rhubarb in a decent sized container filled with top quality potting mix. A half wine barrel is perfect.
The most difficult aspect of growing rhubarb has nothing to do with the plant itself, but everything to do with patience. Don’t harvest any stalks for at least a full year from planting. For the less temperate amongst you, or those who, like me, have an addiction to stewed rhubarb and apple, this waiting game will be excruciatingly hard. But it’s worth it. Give the young plant time to develop a decent sized crown, and you’ll be amply rewarded.
When harvest time finally rolls around, always ensure you gently pull the stems from the crown, rather than cutting. Cut stems create an ideal entry point for fungal attack, and in wet summers, this can lead to crown rot. Also, it’s important to not harvest too many stalks in a single summer. Leave about half to grow to maturity and develop full sized leaves, as these will feed the roots that provide next summer’s crop.
Pests are rarely a problem. Slugs and snails can wreak a bit of havoc with the leaves, but this is mostly an issue of cosmetics. Flavour is unaffected. In my garden possums are the main threat to our enjoyment of rhubarb and apple for dessert. Believe it or not, they manage to eat the leaves without being poisoned, and in the space of a week, entire plants can be chomped almost to ground level.
One final word of warning: rhubarb leaves are high in oxalic acid. In other words they’re poisonous, and if you manage to chew through around five kilograms of the things, they’ll probably kill you. Seriously though, it’s best to leave them to the possums, and make full use of the stems. Rhubarb and apple – I can taste it now!
First published by The Chronicle 15th August 2009. Image by Emily Barney via flickr.
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Hi John,
If an otherwise healthy plant suddenly starts wilting there is usually a problem at root level, and this is probably the case with your rhubarb. It is true that rhubarb needs plenty of water. Those big leaves dry out quickly in the kind of weather we had earlier this month, but it’s equally true that rhubarb needs good drainage. When planting a new crown it is vital to prepare soil that has plenty of well rotted manure and compost added. This treatment provides nutrients, facilitates drainage when it’s wet but helps retain moisture during dry spells. Drainage is especially important on clay soils.
You’ve done the right thing by no longer watering. The cool weather and rainfall is more than enough to keep the plants happy. I would suggest that you remove any mulch from the crown of the plants for a while and then top dress them with compost (homemade if possible). The worms etc will work it down into the ground and the beneficial micro-organisms in the compost will help combat the pathogens in the soil that are causing the rot. As a last resort, you could also try applying Yates Anti Rot. It may be too late to save one plant but the hopefully the other two can be kept healthy.
Hope that helps, and let me know how you get on.
Cheers,
Justin
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