Rhubarb is a staple in many Ontario gardens, prized for its tart stalks that bring flavor to pies, jams, and sauces. While rhubarb is a hardy perennial, harvesting it properly is essential for keeping the plant productive year after year. Here’s how to pick rhubarb in a way that benefits the crop long-term.

When to Harvest Rhubarb

In Ontario, rhubarb season typically runs from late spring to early summer, with peak harvesting in May and June. A mature rhubarb plant (at least two years old) will be ready for harvesting when its stalks reach 10 to 15 inches in length and have a deep red or green color, depending on the variety. It’s important to wait until the plant is well-established before harvesting, as picking too soon can weaken the plant and reduce future yields.

How to Harvest Without Harming the Plant

Proper harvesting methods ensure that rhubarb continues to thrive. Follow these best practices:

• Pull, Don’t Cut: Instead of cutting the stalks, grasp them near the base and gently twist and pull. This method encourages the plant to grow new stalks and reduces the risk of disease that can occur from open cuts.
• Leave Enough Stalks Behind: Always leave at least one-third of the stalks intact to maintain the plant’s energy reserves. Removing too many stalks can weaken the plant, reducing its ability to produce in subsequent seasons.
• Remove the Leaves Immediately: Rhubarb leaves are toxic due to their high oxalic acid content. Cut them off and compost them safely to prevent accidental ingestion by pets or children.
• Avoid Late-Season Harvesting: Stop harvesting by mid-summer to allow the plant to recover and store energy for the next growing season. Overharvesting late in the season can stress the plant and result in reduced growth the following year.

Encouraging Long-Term Growth

For a healthy rhubarb crop year after year, consider these additional tips:

• Fertilize in Early Spring: Apply a balanced fertilizer or compost around the plant to support strong growth. Rhubarb benefits from nutrient-rich soil, so adding organic matter like well-rotted manure can help improve soil structure and fertility.
• Mulch for Moisture Retention: Adding mulch around the base helps retain moisture, regulate soil temperature, and suppress weeds that compete for nutrients. Organic mulches such as straw, wood chips, or grass clippings are excellent choices.
• Divide Older Plants: Every five to ten years, divide large rhubarb plants to keep them vigorous and prevent overcrowding. Dividing rhubarb also helps rejuvenate the plant and can lead to more robust stalk production.
• Water Consistently: Rhubarb prefers moist but well-drained soil, so regular watering during dry spells is crucial. A deep watering once a week is better than frequent shallow watering, as it encourages strong root development.
• Monitor for Pests and Diseases: Although rhubarb is relatively pest-resistant, keep an eye out for common issues such as rhubarb curculio (a weevil that bores into stalks) and fungal infections like crown rot. Removing affected stalks promptly and maintaining good air circulation around the plant can help prevent problems.

Sustainable Rhubarb Harvesting

By harvesting rhubarb correctly and caring for the plant throughout the season, you’ll ensure a bountiful crop for years to come. Sustainable practices, such as rotating your harvest area and not overpicking from the same plant, can help maintain its productivity. Additionally, incorporating companion planting with crops like onions or garlic can help deter pests naturally.

Using Your Harvest

Once harvested, rhubarb can be used in a variety of delicious recipes. It pairs well with sweet flavors like strawberries, apples, and vanilla. Whether you’re making a classic rhubarb pie, a refreshing compote, or even a tangy barbecue sauce, fresh rhubarb is a versatile ingredient. To preserve rhubarb for later use, it can be frozen by cutting the stalks into pieces and placing them in airtight containers or freezer bags.

Final Thoughts

Ontario’s climate provides an excellent environment for growing rhubarb, and by following proper harvesting techniques, gardeners can enjoy a thriving crop year after year. Whether you’re a beginner or a seasoned grower, taking the time to care for your rhubarb plants properly will reward you with a consistent and delicious harvest season after season. Happy harvesting!