RHS Growing Guides
How to grow rhubarb
Our detailed growing guide will help you with each step in successfully growing Rhubarb.
Getting Started
Rhubarb crops reliably every year with little maintenance
The leaf stalks are usually picked during spring and early summer, but plants can be covered with large pots or
Some initial patience is required, as you shouldn’t harvest any stems in the first year after planting, and only a few in the second, to allow the plant to get well established. In the third year, you can harvest normally, taking up to a third of the stalks at any one time.
Rhubarb is a vegetable rather than a fruit, but it's traditionally eaten as a dessert, baked in pies and crumbles. Although you can use it in many more ways, including tangy chutneys and savoury sauces.
Month by Month
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Choosing
Rhubarb stems vary in size and colour, depending on the variety
Varieties with an RHS Award of Garden Merit (AGM) performed well in RHS trials – see our list of AGM fruit and veg (135kB pdf) and our Recommended Varieties below. RHS Garden Bridgewater holds the National Collection of Rheum × hybridum cvs. (culinary) with over 100 varieties of rhubarb, many of historical interest – visit in spring or summer to see the different varieties. You can also see a wide range of vegetables and fruit in all the RHS gardens, so do visit for lots of inspiration and growing tips.
What and where to buy
Before buying, it’s also worth asking fellow gardeners if they have any rhubarb plants to spare. Established clumps should be divided about every five years, in late autumn or winter, to keep them cropping well. This process produces several new plants each time – ideal for sharing with friends.
Recommended Varieties
Produces sweet bright red stems without the need for forcing. Heavy cropper from April.
Early variety, ideal for forcing. Produces lots of thick red stems.
Reliable old variety – very productive, with greenish stems flushed red.
Preparing the Ground
Rhubarb grows best in an open, sunny site with fertile, moisture-retentive soil that doesn't get waterlogged. It will also cope in light shade. If your soil is heavy clay and/or has poor drainage, plant in raised beds or large containers. Although rhubarb is very hardy, it’s best not to plant it in a site prone to late frosts, as the young stems may be damaged. Late-cropping varieties are a good choice for cold sites.
Prepare the planting site by removing weeds, then dig in two bucketfuls of well-rotted organic matter, such as homemade garden compost, per square metre/yard. Alternatively, if you're practicing no-dig, mulch the soil with organic matter ahead of sowing or planting directly into the mulch.
Sowing
Growing rhubarb from seed is not the easiest or quickest option, but it's the cheapest way to produce lots of plants. Seed-raised plants are slower to get established than rhubarb bought as bare-root or potted plants, which already have strong roots. They are also more variable in quality, as bought plants are produced by division so are exact clones of their parent.
If you decide to grow rhubarb from seed, sow indoors in late winter. Sow seed 2.5cm (1in) deep into modules filled with peat-free seed compost. Plant out in late spring or autumn. Alternatively, sow outside in spring, into a prepared seedbed at a depth of 2.5cm (1in). Thin seedlings to 15cm (6in) apart, with further thinning and transplanting of young plants to their final spacing of 75–90cm (30–35in) apart.
Planting
Space plants up to 90cm (35in) apart, as they'll soon form large clumps
- Container-grown plants – are sold all year round for planting at any time, although spring or autumn are best. Avoid planting in very hot, dry weather
- Bare-root crowns – are generally available from November to March and should be planted soon after you receive them
Dig a planting hole that’s just a little wider than the root system. Position the plant so the tip of the crown, or the point where the leaves emerge, is just above the soil surface. Back-fill around the roots with soil, firm in, then water well. If planting more than one, space them 75–90cm (30–35in) apart. For more planting tips, see our guide below.
Planting in containers
If your soil gets waterlogged in winter, or you’re short on soil space, you can grow rhubarb in a large container. Choose a pot at least 50cm (20in) deep and wide, and ideally select a compact variety of rhubarb. Make sure there are plenty of drainage holes and choose a peat-free soil-based compost. Position the plant so its main growth bud or the point where the leaf stalks emerge is just above the compost surface. Be prepared to water regularly during spring and summer.
Plant Care
Once established, rhubarb needs little maintenance, apart from removing flower stems and faded leaves, and mulching in spring. Clumps should also be divided once they become overcrowded. For a crop of early, sweeter stalks, you can force (or blanch) them in winter.
Watering and feeding
Once established, rhubarb rarely needs watering, but young plants and those in containers do need regular attention:
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Newly planted rhubarb – water regularly during dry spells throughout its first growing season, until well rooted
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Established rhubarb plants – water only during prolonged dry periods in summer. Growth will slow down and even stop if conditions are too hot and dry
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Rhubarb in containers – water regularly throughout the growing season, as the compost will dry out quickly. Keep it moist but never waterlogged. Waterlogged compost can lead to roots rotting
Mulching (see below) should provide sufficient nutrients for rhubarb to grow well. If you have poor soil and growth is slow, applying a high-nitrogen, organic-based fertiliser, in spring or summer, will boost growth.
Mulching
Every spring, apply a mulch of well-rotted organic matter, such as homemade garden compost, in a layer about 7cm (2½in) deep around rhubarb plants, but take care not to bury the crown, as that could cause rotting. Mulching helps to retain moisture in the soil and suppress weed growth.
Forcing rhubarb
After you have harvested the first flush of forced stems, remove the covering and allow the plant’s subsequent stems to develop normally. Avoid forcing the same plant in consecutive years. For more information on forcing rhubarb, see our guide below.
Removing flowers
Rhubarb clumps might produce flowering stems in spring and summer, these should be removed at the base as soon as they appear, to prevent them weakening the plant.
It is believed that some varieties are more prone to flowering than others, and that seed raised rhubarb may have a higher likelihood of flowering. Flowering is more common in a wet summer or if a high nitrogen feed has been overused. Also, older plants that haven't been divided for many years are more likely to flower.
Dividing mature plants
Large clumps of rhubarb should be divided every five years or so, especially if the leaves are overcrowded or growth has become weaker. This will give you several vigorous new plants for your own garden or to share with friends, but only propagate from strong healthy plants to ensure they are virus-free. Dig up the entire clump while dormant, between mid-autumn and early spring. Use a spade or an old kitchen knife to slice it into several smaller sections, each with a portion of the rhizome (thickened underground stem) and at least one growing point (bud). Sections from the outer part are better than the centre of old plants. Discard any weak or decayed parts. Replant the sections straight away or wrap them in damp sacking for a short time if necessary.
Overwintering
Harvesting
Rhubarb is best used fresh, but can be frozen or stored in the fridge for a couple of weeks
Most varieties can be harvested from April or May. Although the stems can remain edible and tasty through summer, it’s best to stop harvesting in late June or early July, or at least only take a few stalks from established clumps after then, so you don’t weaken the plant.
To harvest, choose a young stalk about 30cm (1ft) long, with a leaf that has only just fully opened. Hold the stalk at the base and twist gently to ease it out of the ground. Try to avoid snapping it off, and don’t cut it, as you’ll leave a stump that is prone to rotting. Then remove the leaf, which is not edible, and add it to your compost bin. Only ever take about a third of the plant’s stems, so there are plenty of leaves left to keep it in active growth.
Stalks of forced rhubarb are also harvested when they reach about 30cm (1ft), this may take four to eight weeks after covering. After harvesting all the forced stalks, remove the covering to allow light to reach the crown, and don’t harvest any more stalks from that plant until the following year.
Harvest forced and uncovered rhubarb by gently pulling and twisting stalks at the base
Problems
Rhubarb is generally a robust, hardy and healthy plant that can live for at least ten years, and can be kept going far longer if divided regularly. However, there are some potential problems to look out for:
- Slugs and snails may damage young shoots, especially tender shoots under forcing jars
- Late frosts can damage young shoots, so cover with straw or biodegradable fleece if freezing temperatures are forecast
- Rotting in damp conditions, especially in winter – avoid planting rhubarb in a poorly drained site that gets waterlogged, and make sure plants in containers don’t sit in trays of water. If you notice areas of die-back, cut these out promptly before the rot spreads and kills the whole plant
- Split stalks, sometimes exuding sticky sap – this may be caused by late frosts but is often an indication of erratic growth due to fluctuations in growing conditions. Cool or dry periods followed by moist or mild weather means the outer growth splits when the new, rapid growth occurs
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