Rhubarb, with its striking crimson stalks and tart flavor, is a spring and early summer delight for many gardeners and cooks. But knowing when to stop harvesting is crucial for the plant’s health and future yields. Picking too late can weaken your rhubarb, leading to smaller harvests in subsequent years. This guide delves into the intricacies of rhubarb harvesting season, ensuring you get the most from your plant while promoting its long-term well-being.
Understanding Rhubarb’s Growth Cycle
To understand when to stop picking rhubarb, it’s helpful to understand how it grows. Rhubarb is a perennial plant, meaning it lives for many years. Each spring, it sends up new stalks from its underground crown. These stalks are the edible part of the plant. As the weather warms, the plant uses energy to produce these stalks and also to store energy in its roots for the following year. The plant needs time to replenish its energy reserves after a period of intense growth.
Rhubarb thrives in cooler climates, with a dormant period during the winter months. The cold temperatures are actually necessary to stimulate growth in the spring. Once the ground thaws, the plant begins to produce new stalks, signaling the start of harvesting season.
The Importance of Allowing the Plant to Rest
Think of rhubarb harvesting like withdrawing money from a bank account. Every time you pick a stalk, you’re essentially withdrawing energy from the plant. If you withdraw too much, too often, you’ll deplete the account, leaving the plant weakened and unable to thrive. Allowing the plant to rest gives it the chance to replenish its energy reserves, ensuring a healthy and productive plant for years to come. Stopping the harvest at the right time is crucial for long-term productivity.
The Critical Month: Why June is the Stop Sign
While the exact timing can vary depending on your location and the specific variety of rhubarb you’re growing, June is generally considered the cutoff month for rhubarb harvesting in most regions. By the end of June, you should typically stop picking rhubarb stalks. This allows the plant ample time to store energy for the following spring.
Factors Influencing Harvest Timing
Several factors influence the ideal time to stop harvesting rhubarb:
- Climate: In warmer climates, the rhubarb growing season may be shorter, requiring you to stop harvesting earlier in June. Colder climates may allow for a slightly extended harvest, but it’s still best to err on the side of caution.
- Plant Age: Young rhubarb plants, especially those in their first or second year, should be harvested sparingly. Limit harvesting to only a few stalks in the first year and increase gradually in subsequent years. Mature plants can withstand more harvesting.
- Plant Health: A healthy, vigorous rhubarb plant will be better able to tolerate harvesting than a plant that is stressed or struggling. If your rhubarb plant looks weak or unhealthy, it’s best to stop harvesting earlier in the season.
- Variety: Some rhubarb varieties are more vigorous than others. Research your specific variety to understand its growth habits and harvesting recommendations.
Why Harvesting Beyond June is Risky
Harvesting rhubarb stalks beyond June puts undue stress on the plant. It prevents the plant from properly storing energy in its roots, which can lead to:
- Reduced stalk size and quantity in the following year.
- Weaker plants that are more susceptible to pests and diseases.
- A shortened lifespan for the rhubarb plant.
Signs It’s Time to Stop Picking
While the calendar is a good general guide, paying attention to your plant is even more important. Here are some visual cues that it’s time to stop harvesting rhubarb:
- Thin Stalks: If the stalks are becoming noticeably thinner than they were earlier in the season, it’s a sign that the plant is running out of energy.
- Slow Growth: If the new stalks are growing at a slower rate, or not growing at all, it’s another indication that the plant needs a rest.
- Leaf Size: A decrease in the size of the leaves can also signal that the plant is stressed and needs time to recover.
- Bolting: Bolting, where the plant sends up a flower stalk, is a sign of stress. While some flower stalks are normal, excessive bolting can indicate that the plant is struggling. Remove flower stalks as soon as you see them to redirect the plant’s energy back into stalk and root growth.
What to Do After You Stop Harvesting
Once you’ve stopped harvesting rhubarb, there are a few things you can do to help the plant recover and prepare for the next growing season:
- Remove Flower Stalks: As mentioned earlier, remove any flower stalks that appear. This prevents the plant from expending energy on seed production, which is not desirable.
- Fertilize: Fertilize your rhubarb plant with a balanced fertilizer to help it replenish its nutrient reserves. A fertilizer with a higher phosphorus and potassium content can be beneficial for root development.
- Water Regularly: Continue to water your rhubarb plant regularly, especially during dry periods. This helps the plant stay healthy and vigorous.
- Mulch: Apply a layer of mulch around the base of the plant to help retain moisture, suppress weeds, and regulate soil temperature.
- Fall Cleanup: In the fall, after the leaves have died back, you can remove them from the plant. This helps to prevent the spread of disease. You can also add a layer of compost to the soil around the plant to provide additional nutrients.
Dealing With Overgrown Rhubarb
Sometimes, despite your best efforts, rhubarb can become overgrown and produce tough, fibrous stalks. While you shouldn’t harvest these stalks, there are things you can do to rejuvenate the plant:
- Divide the Plant: Dividing a mature rhubarb plant can help to revitalize it. This involves digging up the plant and separating the crown into several smaller pieces, each with its own roots and buds. Replant these divisions in different locations. This is best done in early spring or late fall when the plant is dormant.
- Amend the Soil: Overgrown rhubarb can sometimes be a sign that the soil is depleted of nutrients. Amend the soil with compost and other organic matter to improve its fertility.
- Ensure Adequate Sunlight: Rhubarb needs at least six hours of sunlight per day to thrive. Make sure your plant is getting enough sun.
Rhubarb Varieties and Harvest Times
While June is the general guideline, understanding the specific variety of rhubarb you’re growing can provide more precise harvesting information. Some common rhubarb varieties include:
- Victoria: A popular and reliable variety with green stalks and a good flavor.
- Crimson Red: Known for its intensely red stalks and sweet flavor.
- Canada Red: Another red variety that is very cold-hardy.
- Valentine: A vigorous variety with red stalks and a slightly tart flavor.
Research your specific variety to determine its ideal harvesting period. Local nurseries and gardening resources can provide valuable information on rhubarb varieties that thrive in your area.
Rhubarb Leaf Toxicity: A Crucial Reminder
It’s essential to remember that rhubarb leaves are toxic and should never be eaten. They contain high levels of oxalic acid, which can cause serious health problems. Only the stalks of rhubarb are edible. Always discard the leaves safely, keeping them away from children and pets.
Extending the Rhubarb Season: Forced Rhubarb
For those who crave rhubarb earlier in the season, forcing rhubarb is an option. This involves covering the plant with a light-excluding container in late winter or early spring. This forces the plant to produce stalks earlier than normal, resulting in tender, pink stalks with a sweeter flavor. However, forcing rhubarb weakens the plant, so it should only be done every few years. Also, be careful not to harvest forced rhubarb past the end of the normal harvesting season.
Final Thoughts: Respecting Your Rhubarb Plant
Rhubarb is a rewarding plant to grow, providing a delicious harvest year after year. By understanding its growth cycle and respecting its need for rest, you can ensure a healthy and productive rhubarb plant for many years to come. Remember, stopping the harvest by the end of June is generally recommended, but always pay attention to your plant’s health and vigor. Happy rhubarb harvesting!
By following these guidelines, you’ll be able to enjoy the deliciousness of rhubarb without compromising the health and future productivity of your plant. Remember to observe your rhubarb closely and adjust your harvesting practices based on its individual needs and the specific growing conditions in your region. A little care and attention will go a long way in ensuring a bountiful rhubarb harvest for years to come.
When is the best time to stop harvesting rhubarb in a season?
The optimal time to stop harvesting rhubarb is typically in late spring or early summer, usually around late June or early July. This allows the plant to replenish its energy reserves for the following growing season. Continuing to harvest beyond this point can weaken the plant and reduce its overall productivity in subsequent years.
By allowing the rhubarb plant a period of rest and recovery during the warmer months, it can focus on building strong roots and storing essential nutrients. This ensures a more robust and abundant harvest when the next spring rolls around. Ignoring this critical recovery period can lead to smaller, weaker stalks and an overall decline in the plant’s health.
What happens if I continue to harvest rhubarb stalks after the recommended time?
Prolonged harvesting of rhubarb stalks beyond the late spring/early summer period can significantly weaken the plant. Rhubarb needs this time to rebuild its energy stores in the roots, which are crucial for future growth and stalk production. Over-harvesting essentially deprives the plant of the resources it needs to thrive.
The result of continued harvesting is often diminished vigor, leading to smaller and fewer stalks in subsequent seasons. The plant becomes more susceptible to diseases and pests, and its overall lifespan may be shortened. Essentially, you’re trading short-term gains for long-term consequences by over-harvesting.
How do I know when I’ve harvested enough rhubarb for the season?
A good rule of thumb is to only harvest about one-third to one-half of the total number of stalks from a mature rhubarb plant in any given season. Observe the plant carefully: if it appears less vigorous or the stalks are becoming noticeably thinner and weaker, it’s a clear sign to stop harvesting. Aim for a balanced approach to ensure the plant’s continued health and productivity.
Another indicator is the size of the stalks you are harvesting. Once the new stalks emerging are significantly smaller or thinner than those previously harvested, it signifies that the plant is nearing the end of its productive period for the year. It’s best to allow these smaller stalks to mature and contribute to the plant’s energy reserves rather than harvesting them.
What should I do with rhubarb plants after I stop harvesting for the season?
After ceasing rhubarb harvesting, focus on promoting healthy growth for the following year. Remove any flower stalks that appear, as these divert energy away from root development. Ensure the plant is well-watered, especially during dry spells. Consider applying a layer of compost or well-rotted manure around the base of the plant to replenish nutrients in the soil.
Pay attention to potential pest or disease issues and address them promptly. Keeping the area around the plant weed-free will also reduce competition for nutrients and water. These simple maintenance tasks will help the rhubarb plant recover and prepare for a bountiful harvest in the upcoming season.
Are there any visual cues that indicate it’s time to stop harvesting rhubarb?
Yes, there are several visual cues that suggest it’s time to discontinue rhubarb harvesting. Observe the stalks: if they are becoming thinner and more spindly, it’s a sign that the plant is nearing the end of its productive period. Similarly, if the rate of new stalk production slows down considerably, it indicates that the plant needs to rest and rebuild its reserves.
The appearance of flower stalks is another clear signal. While you should always remove flower stalks to prevent the plant from diverting energy into seed production, their increasing frequency signals that the plant is nearing the end of its harvesting season. Pay attention to these visual indicators to avoid over-harvesting and ensure the plant’s long-term health.
Does the age of the rhubarb plant affect when I should stop harvesting?
Yes, the age of the rhubarb plant can influence the harvesting period. Younger plants, those in their first or second year, should be harvested sparingly, if at all. It’s crucial to allow them to establish strong root systems before significant harvesting begins. Focus on building a healthy, robust plant before prioritizing a large harvest.
More mature plants, typically those three years or older, can be harvested more liberally, but the general guidelines for ceasing harvesting in late spring/early summer still apply. Regardless of age, monitoring the plant’s vigor and stalk size remains the best way to determine when to stop harvesting and allow it to recover for the next season.
Is it ever okay to harvest rhubarb outside of the typical spring/early summer season?
Generally, it’s not recommended to harvest rhubarb outside of the typical spring/early summer harvesting window. Harvesting during the hotter months or in the fall can severely stress the plant and negatively impact its ability to survive the winter. The plant needs this time to store energy for the next growing season.
However, there might be rare exceptions. For instance, if a plant experiences significant damage due to unforeseen circumstances like a storm, selectively harvesting a few undamaged stalks might be acceptable to salvage what you can, but this should be done sparingly and with the plant’s overall health in mind. As a rule, adhere to the spring/early summer harvesting period for optimal plant health and future harvests.