Rhubarb, with its vibrant red stalks and tart flavor, is a spring gardening staple. But harvesting rhubarb isn’t just about grabbing the biggest stalks; it’s about ensuring the plant thrives for years to come. Picking rhubarb correctly encourages continued growth and guarantees a bountiful harvest season after season. In this comprehensive guide, we’ll delve into the best practices for picking rhubarb so your plant remains healthy and productive.
Understanding Rhubarb Growth
Rhubarb is a perennial plant, meaning it lives for multiple years. It grows from a crown, which is the central part of the plant from which the stalks and leaves emerge. The key to successful rhubarb harvesting lies in understanding this crown and how your actions impact its health.
Rhubarb stalks are essentially the plant’s way of storing energy. When you harvest a stalk, the plant uses energy to heal the cut and redirect resources to remaining stalks and the crown. Over-harvesting, or improper harvesting techniques, can weaken the crown and reduce future yields.
The leaves of the rhubarb plant are essential for photosynthesis. Through this process, the plant converts sunlight into energy, which is then used for growth and storage. Therefore, maintaining a healthy amount of foliage is crucial for the plant’s overall well-being.
When to Harvest Rhubarb
Knowing when to harvest rhubarb is as important as knowing how. Harvesting too early can harm the plant, while harvesting too late can result in tough, less flavorful stalks.
Timing is Everything
Generally, rhubarb is ready for harvesting in the spring, usually starting in April or May, depending on your climate. The stalks should be at least 10-12 inches long and about 1 inch thick. These stalks will be much more tender than small, young stalks.
Avoid harvesting rhubarb in the first year after planting. This allows the plant to establish a strong root system and build up its energy reserves. In the second year, you can harvest sparingly, taking only a few stalks. By the third year, your rhubarb plant should be mature enough for a full harvest.
The harvesting season typically lasts for 8-10 weeks. After this period, it’s best to stop harvesting to allow the plant to replenish its energy stores for the following year.
Also, keep an eye on the flower stalks. If your rhubarb plant starts to produce flower stalks, remove them immediately. Flowering diverts energy away from stalk production. Cut them off at the base of the plant as soon as you see them emerge.
Assessing Stalk Readiness
Beyond the length and thickness of the stalks, consider the color and firmness. The best rhubarb stalks will have a vibrant red or pink color (though some varieties are green) and feel firm to the touch. Avoid harvesting stalks that are thin, limp, or showing signs of damage.
The Correct Way to Pick Rhubarb
Now that you know when to harvest, let’s discuss the best techniques for picking rhubarb to ensure continued growth. There are two main methods: pulling and cutting. Pulling is generally considered the better method because it encourages the plant to heal properly.
The Pulling Method
The pulling method involves gently but firmly pulling the stalk from the base of the plant.
- Grasp the stalk near the base: Hold the stalk close to where it emerges from the crown.
- Pull and twist: Gently pull the stalk upwards while twisting it slightly. This should separate the stalk cleanly from the crown.
- Inspect the cut: The base of the stalk should be clean and free of any remaining fibers.
The pulling method is preferred because it stimulates the plant to produce new stalks from the area where the old stalk was removed.
The Cutting Method
While pulling is recommended, you can also cut the stalks. However, it’s crucial to do it correctly.
- Use a sharp knife: A clean, sharp knife is essential to prevent tearing the plant.
- Cut at the base: Cut the stalk at the base, about 1-2 inches above the crown.
- Avoid damaging the crown: Be careful not to damage the crown when cutting.
Cutting can sometimes leave a stub that can rot and potentially harm the plant. If you choose to cut, monitor the cut area for any signs of decay.
How Many Stalks to Pick
It’s essential to avoid over-harvesting rhubarb. A general rule of thumb is to never harvest more than one-third of the stalks at any one time.
- Leave at least 2-3 stalks per plant: This ensures the plant has enough foliage to continue photosynthesis and maintain its energy levels.
- Consider the plant’s size: Larger, more established plants can tolerate more harvesting than smaller, younger plants.
- Monitor the plant’s health: If you notice that the plant is looking stressed or producing fewer stalks, reduce the amount you harvest.
Post-Harvest Care
After harvesting your rhubarb, there are a few things you can do to ensure its continued health and productivity.
Cleaning Up
- Remove any debris: Clear away any dead leaves or debris around the base of the plant.
- Check for pests or diseases: Inspect the plant for any signs of pests or diseases and take appropriate action if necessary.
Fertilizing Rhubarb
Rhubarb is a heavy feeder and benefits from regular fertilization. Apply a balanced fertilizer in the spring before the growing season begins, and again after the harvesting season is over.
- Use a balanced fertilizer: A fertilizer with an NPK ratio of 10-10-10 is a good choice.
- Apply compost: Adding compost around the base of the plant can also provide essential nutrients and improve soil health.
- Avoid over-fertilizing: Too much fertilizer can damage the plant.
Watering Rhubarb
Rhubarb needs consistent moisture, especially during the growing season. Water deeply and regularly, especially during dry spells. Avoid overwatering, which can lead to root rot.
- Water deeply: Water the plant thoroughly, allowing the water to soak down to the roots.
- Water in the morning: Watering in the morning allows the foliage to dry before nightfall, reducing the risk of fungal diseases.
- Mulch around the plant: Mulching helps to retain moisture in the soil and suppress weeds.
Dealing with Flower Stalks
As mentioned earlier, promptly remove flower stalks as soon as you see them appear. They divert energy from stalk production and can weaken the plant. Cut them off at the base with a sharp knife.
Troubleshooting Rhubarb Problems
Even with the best care, rhubarb plants can sometimes encounter problems. Here are a few common issues and how to address them:
Small Stalks
If your rhubarb plant is producing small stalks, it could be due to several factors:
- Over-harvesting: Reduce the amount you harvest to allow the plant to recover.
- Lack of nutrients: Fertilize the plant with a balanced fertilizer or compost.
- Insufficient sunlight: Rhubarb needs at least 6 hours of sunlight per day.
- Crowded conditions: Divide the plant if it has become overcrowded.
Rotting Stalks
Rotting stalks can be a sign of root rot or other fungal diseases.
- Improve drainage: Ensure the soil is well-draining and avoid overwatering.
- Remove affected stalks: Cut off any rotting stalks at the base of the plant.
- Apply a fungicide: If the problem persists, consider applying a fungicide.
Pests and Diseases
Rhubarb is generally resistant to pests and diseases, but it can occasionally be affected by issues like crown rot or rhubarb curculio.
- Crown rot: This fungal disease can cause the crown to rot. Improve drainage and avoid overwatering to prevent it.
- Rhubarb curculio: This weevil can damage the stalks and leaves. Remove affected foliage and use an insecticide if necessary.
Dividing Rhubarb Plants
Over time, rhubarb plants can become overcrowded, which can reduce their productivity. Dividing the plant every 4-5 years can help to rejuvenate it.
When to Divide
The best time to divide rhubarb is in the early spring, before the plant starts to actively grow, or in the fall after the foliage has died back.
How to Divide
- Dig up the plant: Carefully dig up the entire plant, being careful not to damage the roots.
- Divide the crown: Use a sharp knife or spade to divide the crown into sections, ensuring that each section has at least one bud (eye).
- Replant the divisions: Replant the divisions in well-prepared soil, spacing them about 3-4 feet apart.
Enjoying Your Rhubarb Harvest
After all your hard work, it’s time to enjoy the fruits (or rather, stalks) of your labor. Rhubarb is a versatile ingredient that can be used in a variety of dishes, from pies and crumbles to jams and sauces.
Storing Rhubarb
- Refrigerate: Fresh rhubarb stalks can be stored in the refrigerator for up to a week. Wrap them in a damp paper towel and place them in a plastic bag.
- Freeze: Rhubarb can also be frozen for longer storage. Cut the stalks into 1-inch pieces and blanch them in boiling water for 1 minute. Drain and cool the rhubarb, then freeze it in a single layer on a baking sheet. Once frozen, transfer the rhubarb to a freezer bag or container.
By following these tips, you can pick rhubarb so it keeps growing, ensuring a bountiful and delicious harvest for years to come. Proper harvesting techniques, along with attentive care and maintenance, will keep your rhubarb plant healthy, productive, and a source of pride in your garden.
When is the best time to harvest rhubarb?
The optimal time to harvest rhubarb is during the spring, typically from April to June. The stalks are usually ready for harvest when they are at least 10-12 inches long and about 1 inch thick. Avoid harvesting during the first year after planting to allow the plant to establish a strong root system. After the first year, you can begin harvesting lightly.
Stop harvesting rhubarb by mid-summer to allow the plant to store energy for the following year. Harvesting too late in the season can weaken the plant and reduce its productivity in subsequent years. The exact timing may vary slightly depending on your climate and the specific rhubarb variety.
How do I properly harvest rhubarb stalks without damaging the plant?
The best way to harvest rhubarb stalks is by pulling them from the base of the plant rather than cutting them. Grip the stalk firmly near the base and gently twist and pull upwards. This method encourages the plant to continue producing new stalks and reduces the risk of disease entering the plant through cut stems.
Avoid removing more than one-third of the stalks at any one time. Over-harvesting can stress the plant and hinder its growth. It’s better to harvest regularly throughout the season, taking only the largest, most mature stalks each time, rather than stripping the plant bare all at once.
Can I eat rhubarb leaves?
No, rhubarb leaves are poisonous and should never be eaten. They contain high levels of oxalic acid, which can cause serious illness or even death if ingested. Always discard the leaves after harvesting the stalks and ensure they are kept away from children and pets.
The oxalic acid concentration varies, but even a small amount of rhubarb leaves can cause symptoms such as nausea, vomiting, and abdominal pain. It’s crucial to only consume the stalks of the rhubarb plant, which are perfectly safe and delicious when cooked.
How often should I water my rhubarb plant?
Rhubarb plants prefer consistent moisture, especially during the growing season. Water deeply and regularly, aiming to keep the soil consistently moist but not waterlogged. A good rule of thumb is to water when the top inch or two of soil feels dry to the touch.
During periods of heavy rainfall, you may need to reduce watering frequency to prevent root rot. Similarly, during hot, dry spells, you may need to water more frequently to keep the plant hydrated. Mulching around the base of the plant can help retain moisture and reduce the need for frequent watering.
What type of fertilizer is best for rhubarb?
Rhubarb benefits from a balanced fertilizer applied in early spring. A fertilizer with an N-P-K ratio of 10-10-10 or similar is a good choice. Apply the fertilizer according to the package instructions, being careful not to over-fertilize, which can damage the plant.
Alternatively, you can use compost or well-rotted manure as a natural fertilizer. These organic options provide essential nutrients and improve soil structure. Apply a layer of compost or manure around the base of the plant in the spring. Avoid using fertilizers high in nitrogen, as they can promote leaf growth at the expense of stalk production.
How do I know if my rhubarb plant is healthy?
A healthy rhubarb plant will have large, vibrant green leaves and thick, sturdy stalks. The stalks should be a rich red or green color, depending on the variety. The plant should also be actively producing new stalks throughout the harvesting season. Look for signs of vigorous growth and overall vitality.
If your rhubarb plant has yellowing or wilting leaves, thin or weak stalks, or shows signs of pest infestation or disease, it may be unhealthy. Check for common rhubarb pests like aphids or slugs, and address any issues promptly. Ensure the plant is receiving adequate water and nutrients, and consider amending the soil if necessary.
Can I divide my rhubarb plant to propagate it?
Yes, rhubarb plants can be divided to propagate new plants, typically in early spring or late fall when the plant is dormant. Dig up the entire plant and carefully divide the crown into sections, ensuring each section has at least one healthy bud (also known as an “eye”) and a good portion of roots.
Replant each division in a prepared location with well-draining soil and plenty of sunlight. Water thoroughly after planting and keep the soil consistently moist until the new plants are established. Dividing rhubarb can help rejuvenate older plants and increase your rhubarb crop.