Preparing Your Rhubarb Planting Site
To establish a productive rhubarb patch that will yield for years, the initial preparation is paramount. Rhubarb is a perennial, meaning it will occupy its spot for a considerable time, so choosing the right location and ensuring the soil is receptive is crucial for future harvests. You're aiming for a site that receives ample sunlight, ideally at least six hours per day, though it can tolerate some partial shade.
The soil itself needs to be rich, deep, and well-drained. Rhubarb dislikes waterlogged conditions, which can lead to root rot. Aim for a soil pH between 6.0 and 6.8. Before planting, deeply dig over the area, incorporating generous amounts of well-rotted compost or farmyard manure. This organic matter will improve soil structure, retain moisture, and provide essential nutrients. Aim to incorporate at least a spade-full of compost per square metre.
Consider the mature size of rhubarb plants. Each crown can spread to about 1 metre (3 feet) in diameter. Therefore, spacing is vital. When planting multiple crowns, allow at least 1.2 metres (4 feet) between them to ensure adequate air circulation and space for growth, preventing overcrowding that can lead to disease and reduced yields.
When you receive your rhubarb crowns, they may look dry and dormant, which is perfectly normal. Ideally, plant them as soon as possible after purchase. If immediate planting isn't feasible, store them in a cool, frost-free place, perhaps in a damp sack or loosely wrapped in plastic, for a short period, but do not let them dry out excessively.
- Choose a sunny spot with at least six hours of light.
- Ensure soil is rich, deep, and well-drained.
- Incorporate plenty of compost or manure.
- Allow 1.2 metres spacing between crowns.
Preparing the Soil Bed
Digging the planting area to a depth of at least 45cm (18 inches) is recommended. This encourages strong root development. As you dig, break up any large clods of soil and remove stones or perennial weeds. Generously mix in your chosen organic matter throughout the entire dug area, not just in the planting hole itself. This creates a beneficial environment for the roots to spread into over time.
Considering Alternative Planting Locations
While a dedicated patch is ideal, rhubarb can also be grown in large containers or raised beds if garden space is limited or soil conditions are poor. For containers, select one at least 60cm (2 feet) in diameter and depth, using a high-quality potting mix enriched with compost. Ensure containers have ample drainage holes. Raised beds offer excellent drainage and can be filled with an optimal soil mix, making them a viable alternative for challenging garden plots.
The Planting Process for Rhubarb Crowns
With your site prepared and your rhubarb crowns ready, the planting itself is relatively straightforward. The most common method involves digging a hole sufficiently large to accommodate the root system comfortably. The goal is to position the crown so that the buds are just at or slightly below the soil surface.
Dig a hole approximately 40cm (16 inches) wide and 30cm (12 inches) deep. Place a layer of compost or well-rotted manure at the bottom of the hole, then lightly mix it with the soil you removed. Position the rhubarb crown in the centre of the hole. The buds, which are the growing points for new stems and leaves, should be facing upwards. Ensure the top of the crown, where these buds are located, is about 5cm (2 inches) below the soil surface.
If planting multiple crowns, maintain the 1.2-metre spacing. Backfill the hole with the excavated soil, mixing in more compost as you go. Gently firm the soil around the crown to eliminate large air pockets, but avoid compacting it too heavily. Water thoroughly after planting to help settle the soil and provide essential moisture to the roots.
It is imperative not to harvest any stalks in the first year after planting. The plant needs this time to establish a strong root system. Disturbing it too soon can severely stunt its growth and delay fruiting (or rather, stalk production) for subsequent years. Think of this first year as an investment in future bounty. You might see a few small stalks emerge; it is best to remove these as soon as they appear to direct the plant's energy entirely into root development.
The first year is for the roots; the subsequent years are for your enjoyment.
Planting Depth Nuances
The correct planting depth is critical. Planting too deep can lead to the crown rotting, while planting too shallow can expose the buds to frost damage or drying out. The general rule is to have the buds just visible or covered by a thin layer of soil. If your crown has a very prominent central woody section with buds on the sides, ensure the buds are oriented upwards and slightly exposed, with the woody base covered.
Establishing Your Rhubarb: First Year Care
The first year after planting is all about encouraging robust root establishment. While the plant might look established on the surface, its primary energy is being channelled underground. Consistent watering is key, especially during dry spells. Keep the soil around the crown consistently moist but not waterlogged. Aim to water deeply, allowing the moisture to penetrate the soil around the developing root system.
Weeding is also important. Keep the area around the rhubarb crown free from competing weeds, which can steal vital water and nutrients. A mulch of compost or well-rotted manure applied around the plant (but not touching the crown itself) can help retain moisture, suppress weeds, and gradually improve the soil. However, avoid excessive mulching in the very first year, as it can keep the crown too wet if drainage is not perfect.
As mentioned, resist the urge to harvest stalks in the first growing season. Any flower stalks that attempt to form should also be removed promptly. These develop to allow the plant to set seed, which diverts energy away from root growth. By removing them, you encourage the plant to store energy in its roots, preparing it for vigorous growth and harvesting in subsequent years.
Consider a light feed in the second year, but in the first year, the organic matter incorporated into the soil should provide sufficient nutrition. The focus remains on hydration, weed control, and letting the plant build its strength unseen.
If you are planting in spring, water very generously after planting and continue to water regularly throughout the first summer, especially if conditions are dry. This helps settle the soil and encourages new root growth.
Weed Control Strategies
Effective weed management ensures your rhubarb gets the resources it needs. Hand-pulling is the most precise method, especially around the young crown. A layer of mulch can suppress many annual weeds, but perennial weeds with deep roots may still need to be tackled manually. Avoid using herbicides, as they can harm the plant and contaminate the soil.
Rhubarb After the First Year: Ongoing Care and Harvesting
Once your rhubarb has successfully established over its first year, it will require less intensive care but will reward you with plentiful harvests for many years to come. In the second year, you can begin to harvest a small amount of stalks, but still avoid taking too much. Aim to harvest no more than one-third of the available stalks to allow the plant to continue building strength. From the third year onwards, you can harvest more freely.
Apply a generous dressing of well-rotted compost or manure around the base of the plant in early spring. This provides essential nutrients for the new growth. You can also supplement this with a balanced, slow-release fertiliser if your soil is known to be poor. Ensure the feed is applied to the soil surface around the plant, not directly onto the crown, to avoid scorching.
Continue to keep the area weed-free. Water during prolonged dry spells, particularly if you are growing in pots or raised beds, or if you wish to extend the harvesting season. Rhubarb prefers moist soil for optimal growth. Avoid over-watering, but ensure it doesn't completely dry out during warmer months.
Harvesting typically takes place from spring through to mid-summer. Pull stalks firmly at the base, or cut them with a sharp knife. Avoid breaking them off haphazardly, which can damage the crown. Stop harvesting by mid-summer (usually around June or July) to allow the plant to recover and store energy for the following year. Harvesting too late can weaken the plant.
To encourage early cropping, you can try 'forcing' rhubarb by covering the crown with a dedicated rhubarb forcer or a large bucket in late winter. This creates a dark, warm environment, stimulating early growth. Ensure good ventilation on milder days to prevent overheating.
Pruning and Division of Crowns
While rhubarb doesn't require pruning in the traditional sense, you will need to remove any dead or damaged leaves and stalks at the end of the season or in early spring. If your plant becomes less productive after several years (typically 5-10 years), it may be time to divide the crowns. This rejuvenates the plant and provides new crowns for planting elsewhere. In early spring, carefully dig up the entire crown and use a spade or sharp knife to divide it into sections, ensuring each section has at least one healthy bud and a good portion of root. Replant these divisions immediately into well-prepared soil.
Common Issues and How to Address Them
Rhubarb is generally a robust plant, but a few common issues can arise if conditions aren't optimal. Understanding these problems and their solutions will help ensure your rhubarb continues to thrive.
Leaf Spot (Ramularia varians): This fungal disease appears as small, dark spots on the leaves, often surrounded by a yellow halo. While unsightly, it rarely affects the edibility of the stalks. Good air circulation, achieved through proper spacing, and removing affected leaves in autumn can help prevent its spread. Avoid overhead watering if possible.
Crown Rot: Caused by waterlogged soil, crown rot leads to the mushy decay of the rootstock. Symptoms include wilting leaves and general poor growth. The best preventative measure is ensuring excellent drainage when preparing the planting site. If crown rot is suspected, remove affected parts or the entire plant to prevent spread, and replant in a better-drained location.
Pest Problems: Slugs and snails can be attracted to the young shoots and tender leaves. Physical barriers, beer traps, or specific slug pellets can be employed. Aphids may occasionally infest the undersides of leaves or young stems. A strong jet of water or an insecticidal soap solution can often clear them. The presence of beneficial insects like ladybirds usually keeps aphid populations in check naturally.
Bolting (Flowering): While not an issue for root development, plants can send up a flower stalk. This diverts energy from stalk production. Remove flower stalks as soon as they appear, as detailed earlier. Stress from drought, extreme cold snaps, or transplant shock can encourage bolting.
Choosing the Right Variety
While the planting method is universal, different rhubarb varieties offer variations in colour, flavour, and season. 'Timperley Early' is known for producing early, tender stalks. 'Victoria' is a classic, reliable variety with green stalks and a tart flavour. 'Glaskins Perpetual' is a more tender, less stringy option that can be harvested for a longer period. When selecting crowns, consider your preferred flavour profile and when you wish to harvest.