Rhubarb is a popular vegetable in the UK, often used in pies, tarts, and jams. Forcing rhubarb is a technique used to produce early stalks, which can be harvested in late winter to early spring. In this article, we will explore the best time to force rhubarb in the UK, the benefits of forcing, and provide a step-by-step guide on how to do it.
What is Forcing Rhubarb?
Forcing rhubarb involves covering the plant with a container or a forcing jar to exclude light and promote early growth. This technique is used to produce tender and sweet stalks, which can be harvested before the plant produces leaves. Forcing rhubarb is a traditional method used in the UK, particularly in Yorkshire, where rhubarb is a staple crop.
Benefits of Forcing Rhubarb
Forcing rhubarb has several benefits, including:
- Early Harvest: Forcing rhubarb allows you to harvest the stalks in late winter to early spring, when other vegetables are scarce.
- Tender Stalks: The stalks produced by forcing rhubarb are tender and sweet, making them ideal for eating raw or cooking.
- Increased Yield: Forcing rhubarb can increase the yield of the plant, as it promotes the growth of multiple stalks.
When to Force Rhubarb in the UK
The best time to force rhubarb in the UK depends on the weather and the specific variety of rhubarb. Generally, forcing rhubarb can start in late winter to early spring, around January or February.
Weather Conditions
Before forcing rhubarb, it’s essential to check the weather conditions. Rhubarb needs a period of cold weather to break dormancy, followed by a period of warmth to promote growth. Ideally, the temperature should be around 4-6°C (39-43°F) during the day and around 0-2°C (32-36°F) at night.
Choosing the Right Variety
Not all rhubarb varieties are suitable for forcing. Look for varieties that are specifically bred for forcing, such as ‘Timperley Early’ or ‘Victoria’. These varieties are more compact and produce fewer leaves, making them ideal for forcing.
How to Force Rhubarb
Forcing rhubarb is a relatively simple process that requires some basic equipment and care. Here’s a step-by-step guide on how to force rhubarb:
Equipment Needed
- A rhubarb plant (specifically bred for forcing)
- A forcing jar or container (at least 30cm deep and 30cm wide)
- Straw or compost
- Water
Step-by-Step Instructions
- Prepare the Plant: Before forcing the rhubarb, make sure the plant is healthy and free of pests and diseases. Remove any dead or damaged leaves and stalks.
- Apply Straw or Compost: Apply a layer of straw or compost around the base of the plant to retain moisture and suppress weeds.
- Place the Forcing Jar: Place the forcing jar or container over the plant, making sure it is at least 30cm deep and 30cm wide. The jar should be clear or translucent to allow light to enter.
- Water the Plant: Water the plant thoroughly, making sure the soil is moist but not waterlogged.
- Provide Warmth: Place the forcing jar in a warm location, such as a greenhouse or a sunny windowsill. The ideal temperature is around 10-15°C (50-59°F) during the day and around 5-10°C (41-50°F) at night.
- Monitor the Plant: Monitor the plant regularly, making sure the soil is moist and the stalks are growing. It can take around 4-6 weeks for the stalks to be ready for harvesting.
Harvesting Forced Rhubarb
Forced rhubarb is ready to harvest when the stalks are around 30-40cm (12-16 inches) long and the leaves are still tightly wrapped around the stalk. To harvest, simply twist the stalks gently to release them from the plant.
Tips for Harvesting
- Harvest in the Morning: Harvest the stalks in the morning, when they are at their most tender.
- Use a Sharp Knife: Use a sharp knife to cut the stalks, rather than twisting them off. This will help to prevent damage to the plant.
- Leave Some Stalks: Leave some stalks on the plant to allow it to continue growing and producing new stalks.
Common Problems and Solutions
Forcing rhubarb can be a rewarding experience, but it’s not without its challenges. Here are some common problems and solutions:
Pests and Diseases
- Slugs and Snails: Slugs and snails can be a problem when forcing rhubarb. Use copper tape or crushed eggshells to deter them.
- Botrytis: Botrytis is a fungal disease that can affect rhubarb. Remove any infected leaves or stalks, and improve air circulation around the plant.
Environmental Factors
- Extreme Temperatures: Extreme temperatures can affect the growth of forced rhubarb. Keep the plant in a location with a consistent temperature.
- Lack of Light: Forced rhubarb needs some light to grow. Make sure the forcing jar is clear or translucent to allow light to enter.
In conclusion, forcing rhubarb is a traditional technique used in the UK to produce early stalks. By following the steps outlined in this article, you can enjoy tender and sweet rhubarb stalks in late winter to early spring. Remember to choose the right variety, provide the right conditions, and monitor the plant regularly to ensure a successful harvest.
What is forcing rhubarb, and how does it differ from regular rhubarb cultivation?
Forcing rhubarb is a horticultural technique used to stimulate early growth and production of rhubarb stalks. This method involves covering the rhubarb plant with a container or a forcing pot to create a dark, warm, and humid environment. This process tricks the plant into thinking it’s spring, causing it to produce stalks earlier than it would naturally. In contrast, regular rhubarb cultivation relies on natural sunlight and temperature fluctuations to stimulate growth.
The primary difference between forced and regular rhubarb cultivation lies in the timing and quality of the harvest. Forced rhubarb is typically ready to harvest 6-8 weeks earlier than regular rhubarb, and the stalks are often more tender and sweeter. However, forcing rhubarb requires more maintenance and care, as the plant needs to be protected from extreme temperatures and moisture levels.
When is the best time to force rhubarb in the UK?
In the UK, the ideal time to force rhubarb is from late winter to early spring, typically around January or February. This allows the plant to produce stalks before the natural growing season begins. It’s essential to wait until the plant has gone dormant, usually after a few frosts, to ensure the forcing process is successful.
Before forcing, make sure the rhubarb plant is at least a year old and has a good root system. It’s also crucial to choose a variety that is suitable for forcing, such as ‘Timperley Early’ or ‘Victoria’. These varieties are bred specifically for their ability to produce high-quality stalks under forced conditions.
How do I prepare my rhubarb plant for forcing?
To prepare your rhubarb plant for forcing, start by removing any dead or damaged leaves and stalks. This will help prevent disease and encourage healthy growth. Next, apply a layer of compost or well-rotted manure around the base of the plant to provide nutrients. If your soil is heavy clay or sandy, mix in some organic matter to improve its structure.
About 4-6 weeks before forcing, stop watering the plant to allow it to go dormant. This will help the plant conserve energy and prepare for the forcing process. Once the plant is dormant, you can cover it with a forcing pot or container, making sure to exclude any light.
What type of container should I use to force my rhubarb?
When choosing a container to force your rhubarb, select one that is specifically designed for this purpose. Rhubarb forcing pots or containers are typically made of terracotta or ceramic materials and have a narrow neck to exclude light. These containers are designed to create a warm, humid environment that promotes healthy growth.
Alternatively, you can use a large bucket or container with a lid, such as a dustbin or a large tub. Make sure to drill some holes in the bottom for drainage and cover the top with a lid or a brick to exclude light. Whatever container you choose, ensure it is clean and free of any debris or disease.
How long does it take to force rhubarb, and when can I expect to harvest?
The forcing process typically takes around 6-8 weeks, depending on the variety, weather conditions, and temperature. During this time, the plant will produce a crop of tender, sweet stalks. You can expect to harvest your forced rhubarb in late February or early March in the UK, about 6-8 weeks before the natural harvest time.
When harvesting, use a sharp knife to cut the stalks at the base, leaving about 1 inch of stem attached to the crown. Avoid pulling the stalks, as this can damage the plant. Harvest the stalks regularly to encourage the plant to produce more, and stop harvesting when the stalks become tough or fibrous.
Can I force rhubarb in a cold frame or greenhouse?
Yes, you can force rhubarb in a cold frame or greenhouse, provided it is cool and dark. Rhubarb plants require a period of cold temperatures to break dormancy, so avoid forcing in a warm greenhouse. A cold frame or unheated greenhouse is ideal, as it provides protection from extreme temperatures and moisture.
Make sure to cover the rhubarb plant with a layer of straw or compost to maintain humidity and exclude light. You can also use a forcing pot or container within the cold frame or greenhouse to create a warm, humid microclimate. Monitor the temperature and ensure it remains cool, around 5-10°C (40-50°F), to promote healthy growth.
Are there any potential risks or drawbacks to forcing rhubarb?
While forcing rhubarb can be a rewarding experience, there are some potential risks and drawbacks to consider. One of the main risks is disease, particularly crown rot, which can occur if the plant is not properly prepared or if the forcing environment is too humid. Additionally, forcing can weaken the plant, making it more susceptible to pests and diseases.
To minimize these risks, ensure the plant is healthy and well-established before forcing, and provide good air circulation and drainage. Monitor the plant regularly for signs of disease or pests, and take action promptly if you notice any problems. It’s also essential to allow the plant to recover after forcing by providing it with plenty of sunlight and nutrients.