Rhubarb is a perennial vegetable which is often used like a fruit and finds a place in a range of different sweet and savoury recipes. Just one mature plant can offer a worthwhile harvest year after year. But if you have had the same rhubarb plant for a number of years, it can be a good idea to divide rhubarb to make new plants, and breathe new life into your rhubarb patch. As a rule of thumb, a clump of rhubarb can be cropped for ten years or more but should be divided around every five years or so to make sure the yield does not drop.
When To Divide Rhubarb
September, October or November is a good time to think about dividing a mature rhubarb to make new plants, though you can continue to consider undertaking this job any time between autumn and early spring. A plant that is ready for division will be one which looks somewhat weak, or which has become overcrowded. You may have noticed that the year’s harvest was not quite as abundant as that which the plant had produced in previous years.
How To Divide Rhubarb
To divide rhubarb you should:
- Take a spade and cut all round the plant to a depth of around 15cm.
- Remove the plant crown from the ground, keeping roots as in tact as possible.
- Use the spade to divide the crown into sections, each of which should include a portion of the rhizome (thickened root section) and at least one growing point.
- Discard any sections of the plant’s crown which are old, dead or damaged.
- Replant the new rhubarb plants as soon as possible. If you cannot plant them immediately, be sure to keep them moist until you can do so by wrapping them in damp rags.
- Plant rhubarb divisions into a growing area which has been prepared with plenty of organic matter. Make sure you plant them with the growing tip at or just below the surface of the soil. Be sure to space plants at least 1m apart. If you plan to place rhubarb in your polytunnel, it is important to note that it should not be heated over the winter. Rhubarb requires seven to nine weeks of temperatures below around 3 degrees Celsius for best results.
- Do not be tempted to harvest from rhubarb plants in the first season after planting, and harvest only lightly come the second year.
Dividing established rhubarb plants is something that you could consider doing this autumn. Not only can it help to rejuvenate older plants and ensure that they continue to be productive, it can also be a good way to increase plant stocks and yield in your garden.
Do you grow rhubarb in your polytunnel or elsewhere in your garden. Let us know how you have been getting on, or what you like to do with your rhubarb harvest, in the comments below.
Elizabeth Waddington is a writer and green living consultant living in Scotland. Permaculture and sustainability are at the heart of everything she does, from designing gardens and farms around the world, to inspiring and facilitating positive change for small companies and individuals.
She also works on her own property, where she grows fruit and vegetables, keeps chickens and is working on the eco-renovation of an old stone barn.