Unlocking Abundant Harvests: A Comprehensive Guide to Dividing Rhubarb Plants

Rhubarb, with its vibrant crimson stalks and tart flavor, is a delightful addition to any garden. But like many perennials, rhubarb plants benefit from division every few years. This process not only rejuvenates the plant, promoting healthier growth and more abundant harvests, but also allows you to propagate new plants for other areas of your garden or to share with friends. If you’ve noticed your rhubarb stalks getting thinner or your plant becoming overcrowded, it’s likely time for a division. This comprehensive guide will walk you through the entire process, ensuring successful rhubarb division and many more years of delicious crumbles, pies, and jams.

Why Divide Rhubarb?

Before diving into the how-to, let’s explore why dividing rhubarb is so beneficial. As rhubarb plants mature, the crown (the base of the plant where the stalks emerge) becomes congested with many buds and shoots. Over time, this overcrowding leads to several issues:

• Reduced stalk size and thickness: Overcrowding results in competition for resources, leading to thinner, weaker stalks.
• Decreased yields: As the plant’s energy is spread among more shoots, the overall harvest decreases.
• Increased risk of disease: Overcrowded crowns have poor air circulation, making them more susceptible to fungal diseases.
• Stagnant growth: Without division, the plant may become less vigorous and produce fewer leaves and stalks.

Dividing rhubarb addresses these problems by giving each portion of the plant more space and resources. This results in:

• Larger, more robust stalks: Divided plants produce thicker and stronger stalks.
• Increased yields: By giving each portion sufficient space, you encourage higher yields.
• Healthier plants: Better air circulation reduces the risk of disease.
• Propagation: Division provides a way to create new rhubarb plants from your existing one.

When to Divide Rhubarb

Timing is crucial for successful rhubarb division. The best time to divide rhubarb plants is during their dormant period, either in:

• Early spring: Before the plant begins its new growth, when the ground is workable but the plant is still dormant. This is often the preferred method.
• Late autumn: After the plant’s foliage has died back and the plant is entering dormancy. This is another option, but it is recommended to be done early enough that the newly divided plants have time to establish before winter.

Avoid dividing rhubarb during the active growing season, as this can shock the plant and hinder its recovery. Hot weather can also stress the newly divided plants. The ideal temperatures are cool to moderate, between 40°F and 60°F (4°C to 16°C).

Tools and Materials You’ll Need

Before you begin, gather the necessary tools and materials:

• Sharp spade or garden fork: For digging up and dividing the plant. A sharp tool is critical for making clean cuts and minimizing damage to the roots.
• Sharp knife or pruning saw: For separating the crown if the sections are tightly connected.
• Gloves: To protect your hands.
• Tarp or old sheet: To place the plant on after it’s been dug up. This helps prevent the plant from drying out and makes cleanup easier.
• Wheelbarrow or garden cart: To move the divided sections to their new locations if necessary.
• Compost or well-rotted manure: For enriching the soil at the planting site.
• Watering can or hose: For watering after planting.

Step-by-Step Guide to Dividing Rhubarb

Now, let’s get into the step-by-step process of dividing your rhubarb plant. Follow these instructions carefully to ensure success:

Step 1: Preparing the Planting Site

Before you dig up the rhubarb plant, prepare the new planting site(s). Rhubarb thrives in well-drained, fertile soil with plenty of organic matter. Choose a spot that receives full sun (at least six hours per day). Here’s how to prepare the planting site:

• Clear the area: Remove any weeds, grass, or debris from the area.
• Amend the soil: Dig in a generous amount of compost or well-rotted manure to improve soil fertility and drainage. Work the amendments into the top 6-8 inches of the soil.
• Prepare planting holes: Dig planting holes that are at least as wide and as deep as the root ball you’ll be transplanting. Space these holes about 3-4 feet apart if you are planting more than one division. If you are transplanting the division to the same general area where the original plant was, make sure you dig the hole at least 2 feet away from the original hole to provide the new plant with fresh soil.

Step 2: Digging Up the Rhubarb Plant

Carefully dig up the rhubarb plant, being mindful not to damage the roots. Here’s how:

• Loosen the soil: Using your spade or garden fork, begin loosening the soil around the perimeter of the rhubarb plant, about 12-18 inches away from the base of the plant. Dig down around the root system, angling your tool slightly outwards.
• Leverage the plant out: Gently lever the plant up, working your way around the entire circumference of the plant. Try not to force the plant out. If the plant is particularly large, you may need to dig deeper and wider to lift it out without damage.
• Lift and place on tarp: Once the plant is free, carefully lift it out of the hole and place it on your tarp or old sheet. Try to keep as much of the soil around the roots as possible.

Step 3: Dividing the Crown

Now comes the most crucial part of the process: dividing the crown. Here’s what to do:

• Inspect the crown: Examine the crown and identify natural divisions, ensuring each division has at least one good bud (often referred to as an ‘eye’ which is a pink or redish bump) on it.
• Separate the crown: Using your sharp spade, knife, or pruning saw, carefully cut through the crown to create separate divisions. If the plant is relatively small, a sharp spade might be sufficient. For larger, more mature plants, you may need a knife or pruning saw. It’s often easier to make the cuts by working from the top of the crown downwards. Do not worry if you are working with a very large and old plant and you cannot make the divisions clean, as long as each of them has at least one viable bud it will grow well.
• Trim any damaged roots: Inspect the roots of each division and trim away any damaged or overly long roots with your knife or pruners. This will promote the growth of new, healthy roots.
• Divide into smaller sections if needed: For older more mature plants you can divide the crown into multiple divisions each with 1-2 buds. For younger plants you might consider to only have two divisions or even leave the plant as it is if you think it does not need it yet.

Step 4: Planting the Divided Sections

Now it’s time to plant your newly divided rhubarb sections. Follow these steps:

• Place the division in the hole: Position one division in the prepared planting hole, ensuring that the crown (the top of the roots where the buds are located) is level with the soil surface or slightly below. It’s crucial not to bury the crown too deep, as this can lead to rot.
• Backfill with soil: Fill the hole with soil, gently firming it around the plant. If you added compost to the planting hole, use that soil.
• Water thoroughly: Water the newly planted division generously to settle the soil and hydrate the roots.

Step 5: Ongoing Care

Once the divided rhubarb plants are in their new homes, continue with regular care to ensure their successful establishment. Here are some crucial tips:

• Regular watering: Keep the soil consistently moist, especially during dry periods. Newly planted divisions are more vulnerable to drying out.
• Mulching: Apply a layer of organic mulch, such as straw or wood chips, around the plants to help retain moisture, suppress weeds, and regulate soil temperature.
• Fertilizing: In spring, fertilize the plants with a balanced fertilizer to promote strong growth. Alternatively, topdress the soil with compost or well-rotted manure.
• Avoid Harvesting in the First Year: It’s important not to harvest any stalks from newly divided plants in the first year. This allows the plant to focus on establishing a strong root system. Starting from the second year and beyond, you can start your regular harvesting.
• Regularly check for pests and diseases: Be mindful of pests and diseases and take necessary actions as needed, including the application of neem oil or insecticidal soap to treat the issue.

Troubleshooting Common Issues

Even with the best preparation, you may encounter some challenges. Here are some common issues and how to address them:

• Poor growth after division: This is often caused by inadequate watering, a lack of nutrients, or damage to the roots during division. Make sure that the division is properly watered and fertilized and that the roots are not overly damaged.
• Rotting crown: If the crown is buried too deep, it may rot. Always ensure the crown is at or just below the soil surface and ensure proper drainage.
• Slow growth in the first year: This is normal after division. Be patient and focus on providing good care. In the second year, the new division should produce much more stalks.
• Pests and diseases: Monitor plants regularly and take appropriate action to prevent infestations.

Tips for Success

• Use sharp tools: Sharp tools make clean cuts and minimize damage to the roots.
• Don’t divide too frequently: While division is essential, you don’t need to do it every year. Once every 4-5 years is usually sufficient.
• Be patient: New rhubarb plants may take a year or two to become fully established.
• Choose a suitable location: Remember that rhubarb loves sun and well-drained soil.
• Consider the variety: Some varieties might be more vigorous and require division sooner than others.
• Observe your plants: Pay attention to how your rhubarb plants are growing and adjust your care accordingly.

Conclusion

Dividing rhubarb plants is a simple yet essential task that ensures healthy growth and abundant harvests for years to come. By following these detailed instructions and tips, you can successfully divide your rhubarb and enjoy the fruits (or rather, stalks) of your labor. Remember to be patient, provide good care, and your rhubarb plants will flourish. Happy gardening!