Perhaps the greatest feature of rhubarb is its timing. After a long winter, rhubarb shoots begin to emerge when there are still hard frosts and snow to contend with. By the beginning of spring it is possible to make the first harvest. Rhubarb crumble is a great way to celebrate the start of the growing season.
Rhubarb is a herbaceous perennial that grows from a thick mass called a rhizome. It is officially a vegetable, although a cook uses it like a fruit. It has a distinctive tangy flavour, and rhubarb is commonly used as a flavouring for ice cream and yoghurt. Rhubarb can also make delicious chutneys, and is reputed to make a fine bottle of wine.
- October – February
- Planting depth: Buds at surface level
- Planting spacing: 100 cm between plants, 200 cm between rows
- February – June
- Blanch and freeze
Rhubarb has special characteristics regarding its nutritional properties. It is low in calories, especially compared to fruit, but this benefit is often negated in cooking. Sugar is frequently added to rhubarb recipes to offset its acidic taste. Rhubarb contains many vitamins including B vitamins (folates, niacin and B-6), vitamin A, C and notably K, plus minerals like iron, copper, and potassium.
Rhubarb has an additional benefit in alleviating constipation, a property that has been appreciated by people for many thousands of years.
The best time to plant is in rhubarb’s dormant season which starts in autumn. Before buying a rhubarb rhizome, ask someone if they are happy to share some of theirs. The rhizone can be easily divided by cutting with a sharp knife or splitting with a spade.
There are two keys tasks for growing rhubarb:
- At planting
Digging a big hole and cramming it full of well rotten compost and manure
Every late autumn or late winter – covering the rhubarb bed with a thick mulch of well rotten compost and manure
Plant a big hole for the rhubarb rhizone, and fill it at least 50:50 with compost and well rotted manure.
If you provide the rich bed as described above, the rhubarb will do the rest. Rhubarb hardly requires any weeding, as the rhubarb shoots emerge very early in the growing season and smoother weeds with their big broad leaves. Rhubarb grows in the rainy spring weather, and naturally dies back in the summer. Its broad leaves help to provide shade during summer, but it is recommended to regularly water the plant to encourage healthy growth.
Every 5 years of so it is worth lifting the rhubarb and dividing. Wait until the dormant season – and wet weather to make the task easier – and dig under the rhubarb to lift it up. You will find that the rhubarb rhizone has grown considerably, presenting an opportunity to divide it to share with friends and family. This is also the time to refresh and enrich the growing medium with heaps of fresh compost and well rotten manure.
There is a sophisticated way to force rhubarb by growing in large sheds and excluding the light, or a simple way as described here. When you see the rhubarb shoots emerging from the ground in winter (start looking in January) cover the rhubarb with a big bucket. The exclusion of light encourages the plant to develop long, sweet purple stalks earlier in the growing season than if left unforced.
Rhubarb stalks should be pulled off, with a slight twist of the hand, rather than cut. This avoids damaging the plant and ensures you get as much of the stalk as possible.
Remember – don’t eat the leaves! They contain toxins that are poisonous.
There is often not a great variety of rhubarb crowns to choose from in the shops. If you can find them, rhubarb does come in different colours. Some varieties have red stems, others are predominantly green.
You may find someone at the allotment who is happy to dig up and divide the rhubarb they have on their plot (especially in late autumn when the plant is dormant). You can start your own rhubarb plant with this.
Even better if this person can provide a recommendation of sweetness!