Rhubarb, with its vibrant stalks and tart flavor, is a favorite among gardeners and chefs. As a perennial plant, rhubarb offers not only delicious stalks but also ornamental beauty, making it a must-have in any garden or home.
You can also find different rhubarb varieties with many health benefits in your food. If you’re wondering how to grow rhubarb plants successfully, you’ve come to the right place.
This guide will walk you through every process step, from selecting the perfect planting site to harvesting and storing your rhubarb bounty.
Rhubarb Growing Guide Table
Plant Name: Rheum rhabarbarum
Other Name: Pie Plant or Rhubarb plants
Plant Type: Perennial Vegetable
Native Areas: Western China
Light Requirement: Sun to Light Shade
Watering: Moderate; Keep soil moist but not waterlogged
Fertilizer: Balanced fertilizer in early spring
Toxicity: Leaves contain oxalic acid; stalks are edible
Temperature: Hardy in USDA Zones 3-8
Propagation: Division of rhubarb crowns
Soil Type: Well-drained, fertile soil rich in organic matter
USDA Hardiness Zones: 3-8
What is Rhubarb
Rhubarb (Rheum rhabarbarum) is a cool-season vegetable prized for its tart-flavored rhubarb stalks. Originating from Western China, rhubarb has been cultivated for centuries and is cherished for its culinary versatility and ornamental appeal. While often treated as a fruit in culinary preparations, rhubarb is botanically classified as a vegetable and belongs to the Polygonaceae family.
Quick Guide to Growing Rhubarb Plants
Plant Type: Perrenial plant that regrows each year
Light Requirement: Thrives in the sun to light shade of at least 6-8 hours of sunlight daily
Soil Type: Requires well-drained, fertile soil; pH level ideally between 5.5 to 6.5
Watering: Moderate watering needs; soil should be consistently moist but not waterlogged; Avoid overwatering
Fertilizer: Use a Balanced Fertilizer with an NPK ratio of 10-10-10; Apply in early spring before new growth appears
Propagation: Propagate through Division of Established Crowns; Best done in early spring or late autumn when plants are dormant
Planting Depth: Plant rhubarb crowns with the buds just below the soil surface, approximately 2 inches deep
Spacing: Space rhubarb at least 3 to 4 feet apart to allow for adequate growth and air circulation
Mulching: Apply Organic Mulch around the plants to help retain moisture, suppress weeds, and maintain soil temperature
Harvesting: Start harvesting sparingly in the second growing season. Select mature stalks that are at least 12-18 inches long. Avoid harvesting more than one-third of the plant at a time
Pests and Diseases: Monitor for Rhubarb Curculio, Aphids, and Crown Rot; Maintain good garden hygiene and inspect plants regularly
Rhubarb Plant Care
When rhubarb grows, it is essential to provide your rhubarb patch with essential needs as follows:
How to Grow Rhubarb From Crowns and Seeds
Growing rhubarb can be a rewarding experience, whether you choose to start from crowns or seeds. Rhubarb is a perennial herb that can provide a bountiful harvest for many years when adequately established. Here is how to grow rhubarb in detail.
Rhubarb From Crowns:
Choose healthy, well-developed rhubarb crowns from a reputable garden center or nursery. Look for crowns with firm, plump roots and at least one visible bud.
Select a planting site with well-drained soil and direct sunlight to part shade. Avoid poorly drained areas and locations that are prone to standing water.
Amend l with well-rotted manure or compost to improve fertility and drainage. Ensure the soil pH is between 5.5 to 6.5, which is ideal for rhubarb growth.
Dig a planting hole that is wide and deep enough to accommodate the rhubarb crown. Plant crowns in the hole with the buds below the soil surface. Backfill the hole and firm the soil around the crown.
Space crowns at least 3 to 4 feet away from each other to allow for adequate growth and air circulation.
Water the newly planted crowns thoroughly and maintain consistent soil moisture during the growing season. Avoid overwatering, as this can lead to root rot.
Apply a layer of mulch around established plants to retain moisture, suppress weeds, and maintain soil temperature.
Harvest sparingly during the first year to allow the plants to become established. Remove any flower stems that emerge to redirect energy toward root and crown development.
Planting Rhubarb Seed:
Choose high-quality seeds from a reputable supplier. Opt for varieties that are known for their vigor and disease resistance.
Start rhubarb seeds indoors 8-10 weeks before the last frost date in your area. Sow the seeds in seed trays filled with a well-draining potting mix.
Keep the soil moist and maintain a consistent temperature of 65°F to 75°F (18°C to 24°C) for optimal germination. Seeds typically germinate within 2-4 weeks.
Once the seedlings have developed 2-3 true leaves, transplant them into individual pots or containers. Grow them indoors or in a protected area until they are planted outdoors.
Before transplanting seedlings outdoors, gradually acclimate them to outdoor conditions over 7-10 days. Start by placing them in a sheltered location and gradually expose them to longer periods of direct sunlight and outdoor elements.
Choose a planting area with ample drainage and full sun-to-part shade. Space the seedlings at least 3 to 4 feet apart for adequate growth.
Water the seedlings thoroughly after planting and maintain consistent soil moisture throughout the growing season. Apply a layer of mulch to conserve moisture and suppress weeds.
Like crowns, limit harvesting during the first year to allow the plants to become well-established. Focus on promoting healthy growth and development.
Soil and Water Needs to Grow Rhubarb
The Rhubarb plant thrives in fertile soil rich in organic matter. Before planting, amend the soil with composted manure taken from your compost pile to enhance its fertility and structure.
Maintaining moisture is crucial for healthy plant growth, especially during the active growing season in early spring and summer.
Avoid overwatering, as wet soil can lead to root rot and other moisture-related issues.
Light
Plant rhubarb in a location that receives full sun-to-part shade for optimal growth and yield. While rhubarb can tolerate partial shade, it may result in thinner stalks and reduced productivity. Ensure the planting spot offers at least 6-8 hours of direct sunlight daily for robust growth and delicious stalks.
Temperature and Humidity
Rhubarb is a cold-hardy perennial that thrives in USDA Zones 3-8. It requires a period of dormancy during winter, with temperatures below 40°F (4°C), to break dormancy and initiate new growth in spring. While rhubarb can withstand early summer temperatures, adequate moisture and protection from extreme heat are essential for maintaining plant vigor and preventing stress.
Fertilizer
Fertilizing rhubarb is essential for providing nutrients for growth and development. Apply a balanced fertilizer, such as a 10-10-10 NPK formulation, in spring before new growth begins.
Avoid excessive nitrogen, as it can promote lush foliage at the expense of stalk production.
Additionally, top-dressing with compost or rotted manure in late autumn can help replenish soil nutrients and prepare the plants for winter dormancy.
Propagation
Rhubarb is typically propagated by dividing established crowns. Or you can collect the stalks, but it does take a long time for them to grow and harvest rhubarb. We will provide both methods here:
Division:
Lift established clumps in early spring or autumn when the plants are dormant.
Use a sharp knife to divide the crowns, ensuring each division has at least one healthy bud.
Plant the divisions in well-prepared free, draining soil at the same depth as previously growing.
Water thoroughly and monitor the young plants for new growth, indicating successful establishment.
Collecting Seeds from Rhubarb Stalks:
rhubarb seeds @keepps (flickr)
As rhubarb matures, they produce tall flower stalks that eventually develop seeds. The seeds are contained within small, round pods along the stem.
Watch the stalks as they develop, and wait until the pods turn brown and dry out. This indicates that the seeds are mature and ready for harvest.
Carefully cut the stalks from the plant using clean, sharp pruners or scissors. Place the stalks in a paper bag or container to catch falling seeds during harvesting.
Once you’ve collected the seed stalks, allow them to dry in a warm, well-ventilated area for 1-2 weeks. This helps to mature the seeds further and reduce moisture content.
After the seed stalks have dried, gently crush the pods to release the seeds. Separate the seeds from any remaining plant debris or chaff by shaking them in a fine-mesh sieve or strainer.
Store the cleaned seeds in a cool, dry place in an airtight container or sealed envelope. Be sure to label the container with the seed variety and date of collection for future reference.
If you’re unsure about the viability of the seeds, you can perform a simple germination test by placing a few seeds on a damp paper towel in a sealed plastic bag. Keep the towel moist and check for germination after 1-2 weeks.
Important Considerations:
Cross-Pollination: Remember that rhubarb is wind-pollinated, and seeds collected from open-pollinated plants may not produce offspring that are true to the parent plant. To preserve specific traits, consider isolating plants or hand-pollinating to control cross-pollination.
Longevity: Rhubarb seeds have a relatively shorter viability than other vegetable seeds. It’s best to use them within 1-2 years for optimal germination rates.
Alternative Propagation: While collecting seeds can be rewarding, remember that rhubarb is most commonly propagated through the division of crowns to ensure consistent and reliable harvests.
How to Harvest Rhubarb and Store Them
Harvesting rhubarb is a rewarding experience, as it signals the culmination of growing rhubarb. Wait until the second growing season before harvesting to allow the plants to become well-established. When harvesting rhubarb:
Select only a few stalks at least 12-18 inches long.
Grasp the stem near the base and pull it away from the plant with a slight twisting motion.
Avoid harvesting more than one-third of the plant’s stalks at a time to ensure continued growth and vigor.
Trim the leaves from the harvested stalks, as they contain oxalic acid and are not edible.
Store fresh rhubarb stalks in the refrigerator for up to two weeks, or preserve them by freezing or canning for extended storage.
Rhubarb Pests and Troubleshooting
While rhubarb is relatively low-maintenance, it can be susceptible to certain pests and diseases. Common pests include:
Rhubarb Curculio: A beetle that feeds on rhubarb stalks, causing damage and reducing yield. Use insecticidal soap or neem oil to control infestations.
Crown Rot: A fungal disease that affects the roots and crowns of the rhubarb plant. Ensure proper soil drainage and avoid overwatering to prevent crown rot.
Regularly inspecting your rhubarb plants for signs of pests or diseases and taking prompt action can help maintain plant health and productivity.
Frequently Asked Questions
The secret to successfully growing rhubarb is providing the right conditions, including well-draining soil, adequate sunlight, and proper care throughout the season. Additionally, selecting disease-resistant rhubarb varieties and practicing good garden hygiene can help ensure a bountiful harvest.
Rhubarb is relatively easy to grow, especially with the right growing conditions. With minimal care and maintenance, rhubarb plants can thrive and produce abundant harvests for many years.
Rhubarb plants typically require two to three years to become well-established and produce a substantial harvest. However, once established, rhubarb plants can grow tasty leaf stalks for many years with proper care and maintenance.
The best place to plant rhubarb in the garden is in a location that receives enough sun to shade and has well-drained, fertile soil rich in organic matter. Avoid planting rhubarb in poorly drained or waterlogged areas, which can lead to root rot and other moisture-related issues.
No, it would be best if you did not eat rhubarb leaves. They contain high levels of oxalic acid, which can be toxic if ingested in large quantities. Always discard rhubarb leaves and focus on consuming the edible stalks.
Growing rhubarb in a raised bed can benefit from improved drainage, soil control, and easier maintenance. A raised bed also warms up quicker in spring, potentially extending the growth. Yet, ensure the raised beds are deep enough (12-18 inches) to accommodate rhubarb’s deep roots.
Whether you want to buy, sell, or reach out to other plant enthusiasts, Plantly is the right place to be!
