Rhubarb, with its vibrant crimson stalks and tart flavor, is a welcome sign of spring for many gardeners. But harvesting rhubarb isn’t just about enjoying its delicious stalks – it’s also about ensuring the plant’s health and continued productivity for years to come. Cutting rhubarb correctly encourages further growth and prevents damage that could weaken the plant. This guide provides a detailed, step-by-step approach to harvesting rhubarb in a way that maximizes both your harvest and the longevity of your rhubarb patch.
Understanding Rhubarb Growth and Harvesting
Before diving into the specifics of cutting rhubarb, it’s crucial to understand how the plant grows and how harvesting impacts its health. Rhubarb is a perennial plant, meaning it lives for multiple years, dying back to the ground each winter and re-emerging in the spring. The edible stalks we harvest are the petioles of the large leaves. These stalks store energy that the plant uses for growth and reproduction.
Improper harvesting can deplete the plant’s energy reserves, weakening it and reducing future yields. The goal is to harvest stalks in a way that minimizes stress and allows the plant to continue photosynthesizing and storing energy.
The Importance of Mature Plants
Young rhubarb plants need time to establish themselves before harvesting begins. Generally, it’s recommended to wait at least one, and preferably two, growing seasons after planting before harvesting any stalks. This allows the plant to develop a strong root system and build up sufficient energy reserves.
Harvesting young plants too soon can severely stunt their growth or even kill them. Patience is key when it comes to rhubarb. Let the plant mature and flourish before you start enjoying its bounty.
When to Harvest Rhubarb
The optimal time to harvest rhubarb is typically in the spring and early summer, from late April to June. This is when the stalks are at their peak flavor and tenderness. Avoid harvesting rhubarb in the late summer or fall, as this can weaken the plant before winter dormancy.
Stop harvesting when the stalks become thin and the plant seems to slow its growth. This signals that the plant is focusing its energy on other processes, such as root development.
Recognizing Harvestable Stalks
Not all rhubarb stalks are created equal. When harvesting, choose stalks that are at least 12-18 inches long and about 1 inch thick. These stalks are mature enough to be harvested without harming the plant. Avoid harvesting thin, spindly stalks, as these are still developing and contribute to the plant’s overall health.
Focus on harvesting the largest, most mature stalks, leaving the smaller ones to continue growing. This encourages the plant to produce more stalks and ensures a continuous harvest.
The Correct Method for Cutting Rhubarb
The method you use to harvest rhubarb is crucial for its continued growth. While cutting the stalks with a knife might seem like the easiest option, it can actually damage the plant and increase the risk of disease. The preferred method is to pull or twist the stalks from the base.
Pulling vs. Cutting: Which is Better?
Pulling or twisting the stalks is generally considered the better method for harvesting rhubarb because it cleanly removes the stalk from the crown, minimizing the risk of rot and disease. Cutting, on the other hand, can leave behind a stub of the stalk that can rot and potentially spread disease to the rest of the plant.
Pulling the stalk encourages the plant to heal properly and reduces the risk of infection. It also ensures that you’re removing the entire stalk, maximizing your harvest.
Step-by-Step Guide to Harvesting Rhubarb
- Grasp the stalk: Select a mature stalk and grasp it firmly near the base, close to the crown of the plant.
- Twist and pull: Gently twist the stalk while pulling upwards. You should feel the stalk separate from the crown with a slight pop.
- Check for clean removal: Ensure that the entire stalk has been removed, leaving no stub behind. If any part of the stalk remains, carefully remove it with your hand.
- Remove the leaves: Rhubarb leaves contain oxalic acid and are poisonous. Immediately remove the leaves after harvesting the stalks. Discard the leaves in your compost bin or yard waste.
- Repeat: Continue harvesting mature stalks, leaving at least one-third of the stalks on the plant to ensure continued growth and photosynthesis.
Always wear gloves when handling rhubarb leaves to avoid skin irritation. Even though the stalks are edible, the leaves pose a health hazard.
Tools for Harvesting Rhubarb
While pulling or twisting is the preferred method, some gardeners prefer to use a specialized rhubarb harvesting knife. These knives have a curved blade designed to cleanly cut the stalk at the base. If using a knife, be extremely careful not to damage the crown of the plant.
Clean your knife thoroughly after each use to prevent the spread of disease. Hygiene is important when working with any garden tools.
Caring for Rhubarb After Harvesting
Harvesting is just one part of ensuring the continued health and productivity of your rhubarb plant. Proper care after harvesting is equally important.
Fertilizing Rhubarb
After harvesting, rhubarb plants benefit from a feeding of compost or well-rotted manure. This replenishes the nutrients that were used to produce the stalks and encourages new growth.
Apply the compost or manure around the base of the plant, being careful not to bury the crown. This provides a slow-release source of nutrients that will support the plant throughout the growing season.
Watering Rhubarb
Rhubarb plants need consistent moisture, especially during the growing season. Water deeply and regularly, especially during dry periods. Avoid overwatering, as this can lead to root rot.
Check the soil moisture regularly and water when the top inch of soil feels dry. Proper watering is essential for healthy growth.
Weeding Rhubarb
Keep the area around your rhubarb plant free of weeds. Weeds compete with the rhubarb for nutrients and water, and can also harbor pests and diseases.
Regularly remove weeds by hand or with a hoe. Mulching around the plant can also help to suppress weed growth.
Winterizing Rhubarb
As winter approaches, the rhubarb plant will die back to the ground. Once the leaves have turned brown, cut them off at ground level.
Applying a layer of mulch around the crown of the plant can help to protect it from frost damage. This is especially important in colder climates.
Troubleshooting Common Rhubarb Problems
Even with the best care, rhubarb plants can sometimes encounter problems. Being able to identify and address these issues promptly can help to keep your plant healthy and productive.
Rhubarb Pests and Diseases
Rhubarb is generally a hardy plant, but it can be susceptible to certain pests and diseases, such as rhubarb curculio and crown rot.
Rhubarb curculio is a beetle that can damage the stalks and leaves. Handpicking the beetles or using an insecticide can help to control this pest.
Crown rot is a fungal disease that can cause the crown of the plant to rot. Improving drainage and avoiding overwatering can help to prevent this disease.
Bolting Rhubarb
Bolting occurs when the rhubarb plant sends up a flower stalk prematurely. This is usually caused by stress, such as heat or drought. When rhubarb bolts, the stalks become thin and tough.
Remove the flower stalk as soon as you see it to encourage the plant to focus its energy on producing edible stalks. Ensuring adequate watering and providing shade during hot weather can help to prevent bolting.
Thin Stalks
Thin stalks can be a sign of nutrient deficiency, overcrowding, or improper harvesting.
Fertilizing the plant with compost or manure can help to address nutrient deficiencies. If the plant is overcrowded, divide it in the fall or early spring. Ensure that you are harvesting the stalks correctly, leaving enough stalks on the plant to support continued growth.
Dividing Rhubarb for Continued Growth
Over time, rhubarb plants can become overcrowded and less productive. Dividing the plant every few years can help to rejuvenate it and encourage continued growth.
When and How to Divide Rhubarb
The best time to divide rhubarb is in the fall or early spring, when the plant is dormant. To divide the plant, carefully dig it up and use a sharp knife or spade to divide the crown into sections, each with at least one healthy bud.
Replant the divisions in well-drained soil, spacing them about 3-4 feet apart. Water the newly planted divisions thoroughly.
Benefits of Dividing Rhubarb
Dividing rhubarb has several benefits:
- Rejuvenates the plant: Division encourages new growth and increases productivity.
- Controls overcrowding: Division prevents the plant from becoming too crowded, which can reduce yields.
- Propagates new plants: Division allows you to create new rhubarb plants from existing ones.
Enjoying Your Rhubarb Harvest
After all your hard work, it’s time to enjoy the fruits (or rather, the stalks) of your labor. Rhubarb is incredibly versatile and can be used in a variety of dishes, from pies and crumbles to jams and sauces.
Rhubarb Recipes and Uses
Rhubarb is often paired with sweet flavors, such as strawberries, apples, and sugar. It can also be used in savory dishes, such as chutneys and sauces for meat.
Experiment with different rhubarb recipes and find your favorites. There are endless possibilities when it comes to using this delicious and versatile vegetable.
Storing Rhubarb
Freshly harvested rhubarb can be stored in the refrigerator for up to a week. Wrap the stalks in a damp paper towel and place them in a plastic bag.
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 the rhubarb and freeze it in a single layer on a baking sheet. Once frozen, transfer the rhubarb to a freezer bag.
By following these tips and techniques, you can ensure that your rhubarb plant thrives for years to come, providing you with a bountiful harvest of delicious and nutritious stalks. Proper harvesting, care, and maintenance are key to enjoying the full potential of this wonderful perennial plant.
What is the best time of year to harvest rhubarb for optimal growth?
The best time to harvest rhubarb is typically during spring and early summer, usually from April to June. Harvesting during this period encourages the plant to focus its energy on producing new leaves and stalks, promoting continued growth and overall health. Avoid harvesting after late June or early July, as the plant needs to store energy for the following growing season.
Later harvests can weaken the plant, making it more susceptible to pests and diseases. Focus on the earlier months to ensure you’re getting the most from your rhubarb without jeopardizing its future productivity. Remember that new rhubarb plants should not be harvested at all during their first year to allow them to establish strong root systems.
How do I choose which rhubarb stalks to harvest?
When selecting rhubarb stalks for harvest, look for those that are at least 12-18 inches long and about 1 inch thick. Thicker stalks generally indicate that they are mature enough for harvesting. Avoid harvesting any very thin or underdeveloped stalks, as these are still crucial for the plant’s growth and overall health.
Focus on harvesting the outer stalks first, leaving the inner, newer stalks to continue developing. This method ensures you are harvesting the most mature stalks while allowing the plant to maintain its vigor and continue producing new growth. Harvesting from the outside in encourages a longer and more productive harvesting season.
What is the correct method for cutting or pulling rhubarb stalks?
The preferred method for harvesting rhubarb is to gently pull the stalks rather than cut them. To do this, grasp the stalk near the base of the plant and gently twist and pull upwards. This action should separate the stalk cleanly from the crown. Avoid yanking too hard, as this could damage the crown.
If the stalk doesn’t easily pull away, you can use a clean, sharp knife to cut the stalk at the base. Make the cut at a slight angle, about 1-2 inches above the soil line. Avoid leaving any stubs, as these can rot and attract pests or diseases. Whether pulling or cutting, removing the stalk cleanly is crucial for the plant’s continued health.
How much of the rhubarb plant can I harvest at once?
As a general rule, never harvest more than one-third of the rhubarb plant’s stalks at any one time. Over-harvesting can significantly weaken the plant, reducing its ability to photosynthesize and store energy for future growth. This can lead to a decline in overall health and productivity.
Allowing at least two-thirds of the stalks to remain ensures the plant has sufficient foliage to sustain itself. This practice promotes strong root development and allows the rhubarb to thrive year after year. A conservative approach to harvesting will result in a healthier and more productive rhubarb plant in the long run.
What should I do with the rhubarb leaves after harvesting the stalks?
Rhubarb leaves contain high levels of oxalic acid and are considered toxic to humans and animals. They should never be eaten. The safest approach is to compost them. The oxalic acid will break down during the composting process, making the resulting compost safe to use in your garden.
Alternatively, you can dispose of the leaves in your regular yard waste bin, ensuring they are handled properly. Avoid leaving them lying around where pets or children could potentially ingest them. The leaves’ toxicity is a key consideration, making responsible disposal crucial for safety.
How does deadheading or removing flower stalks affect rhubarb growth?
Rhubarb plants occasionally produce flower stalks, especially in warmer climates or if the plant is stressed. Allowing the plant to flower diverts energy away from producing edible stalks and towards seed production. Therefore, it is important to remove flower stalks as soon as you notice them.
To remove a flower stalk, cut it off at its base, close to the crown of the plant. This will redirect the plant’s energy back into producing more stalks and leaves, leading to a more productive harvest. Regular deadheading is an essential practice for maintaining the health and vigor of your rhubarb plant.
How often should I fertilize my rhubarb plant to support continued growth after harvesting?
Rhubarb plants benefit from regular fertilization, particularly after the main harvesting period. Applying a balanced fertilizer, such as a 10-10-10 NPK fertilizer, or a compost tea can replenish nutrients lost during the growing season. Fertilize after the final harvest to help the plant build up reserves for the following year.
Alternatively, amending the soil around the base of the plant with well-rotted compost or manure provides a slow-release source of nutrients. Avoid over-fertilizing, as this can lead to excessive foliage growth at the expense of stalk production. Consistent, moderate fertilization promotes strong root development and a healthy, productive plant.