Growing Rhubarb from Seed: A Complete Guide

Introduction

Growing rhubarb from seed is a rewarding way to cultivate this versatile and hardy plant. While most gardeners prefer to plant crowns or potted plants, starting rhubarb from seed allows you to explore unique varieties, save on costs, and enjoy the satisfaction of growing plants from scratch. Although it takes a bit more time and patience, rhubarb grown from seed can thrive just as well as those planted from crowns.

This guide will cover everything you need to know about growing rhubarb from seed, from sowing and transplanting to caring for and harvesting your plants.

Why Grow Rhubarb from Seed?

Cost-Effective: Seeds are more affordable than purchasing crowns or potted plants.
Variety: Growing from seed gives you access to unique and rare rhubarb varieties.
Scalability: You can grow multiple plants from a single seed packet.
Rewarding Process: Enjoy the satisfaction of nurturing a plant from seed to harvest.
Disease-Free Start: Starting from seed minimizes the risk of introducing diseases that can come with crowns.

Best Rhubarb Varieties to Grow from Seed

1. Victoria

Description: A traditional variety with greenish-red stalks and a sweet-tart flavor.
Best For: Heavy cropping and consistent yields.

2. Glaskins Perpetual

Description: Produces sweet stalks, even late in the season.
Best For: Continuous harvests throughout summer.

3. Raspberry Red

Description: Known for its deep red stalks and sweet flavor.
Best For: Desserts and jams.

4. Timperley Early

Description: An early-maturing variety with tender stalks.
Best For: Early spring harvesting.

When to Sow Rhubarb Seeds

1. Indoors

Sow seeds indoors in late winter or early spring, 8-10 weeks before the last frost.

2. Outdoors

Sow seeds directly outdoors after the last frost in late spring or early summer.

How to Prepare Rhubarb Seeds for Sowing

1. Seed Selection

Purchase rhubarb seeds from a reputable supplier to ensure quality and viability.

2. Soaking Seeds

Soak the seeds in lukewarm water for 2-3 hours before sowing.
This softens the seed coat and improves germination rates.

Sowing Rhubarb Seeds

1. Sowing Indoors

Fill small pots or seed trays with a light, well-draining seed-starting mix.
Sow seeds 1cm deep and cover lightly with soil.
Water gently to moisten the soil.
Place pots in a warm, bright location, such as a windowsill or under grow lights.
Maintain a temperature of 18-21°C (65-70°F) for germination.

2. Sowing Outdoors

Prepare a seedbed by loosening the soil and removing weeds.
Sow seeds 1cm deep, spaced 6 inches apart in rows.
Water the soil lightly and keep it consistently moist.

Germinating Rhubarb Seeds

Rhubarb seeds typically germinate within 10-20 days under optimal conditions.
Thin seedlings once they have their first true leaves, leaving the strongest plants.

Transplanting Rhubarb Seedlings

1. When to Transplant

Transplant seedlings when they are 10-15cm tall and after the last frost date.

2. Preparing the Planting Site

Choose a sunny or partially shaded location with rich, well-draining soil.
Amend the soil with compost or well-rotted manure before planting.

3. Transplanting Steps

Dig a hole large enough to accommodate the seedling’s root system.
Place the seedling in the hole with the crown just above the soil surface.
Space plants 3-4 feet apart to allow for growth.
Water thoroughly after transplanting.

Caring for Rhubarb Grown from Seed

1. Watering

Water regularly during the first year to help establish roots.
Avoid overwatering, as rhubarb dislikes soggy soil.

2. Mulching

Apply a thick layer of mulch around the plants to retain moisture, suppress weeds, and protect the crown.

3. Feeding

Feed rhubarb with a balanced fertilizer in early spring.
Avoid excessive nitrogen, as it promotes leaf growth at the expense of stalks.

4. Removing Flower Stalks

Cut off flower stalks as soon as they appear to redirect energy to the stalks.

Harvesting Rhubarb

1. When to Harvest:

Do not harvest rhubarb in its first year to allow the plant to establish.
Begin harvesting in the second year, from mid-spring to late summer.

2. How to Harvest:

Hold the stalk near the base and gently twist and pull.
Alternatively, use a sharp knife to cut the stalk at the base.
Never harvest more than one-third of the stalks at a time to avoid weakening the plant.

3. Harvesting Tips:

Only harvest stalks that are 12-18 inches long.
Discard the leaves, as they are toxic due to high levels of oxalic acid.

Overwintering Rhubarb Grown from Seed

Cut back dead foliage in late autumn and apply a thick layer of mulch over the crown to protect it from frost.

Common Problems and Solutions

1. Poor Germination

Cause: Seeds not properly soaked or planted too deeply.
Solution: Soak seeds before planting and sow them at the recommended depth.

2. Crown Rot

Cause: Waterlogged soil.
Solution: Ensure the soil is well-draining and avoid overwatering.

3. Slugs and Snails

Cause: Feeding on young seedlings.
Solution: Use slug deterrents, traps, or copper tape.

4. Weak Growth

Cause: Nutrient deficiency.
Solution: Feed plants with a balanced fertilizer and add organic matter to the soil.

FAQs About Growing Rhubarb from Seed

1. How long does it take to grow rhubarb from seed?
It takes 1-2 years for rhubarb grown from seed to produce a harvestable crop.

2. Can rhubarb seeds be sown directly outdoors?
Yes, sow seeds outdoors after the last frost when the soil is warm.

3. Do rhubarb seeds need soaking?
Soaking seeds before planting improves germination rates.

4. When should I transplant rhubarb seedlings?
Transplant seedlings when they are 10-15cm tall and after the last frost.

5. How do I protect rhubarb from frost?
Apply mulch over the crown in late autumn or use fleece for protection.

6. Can rhubarb grow in shade?
Rhubarb prefers full sun but can tolerate partial shade.

7. What’s the best fertilizer for rhubarb?
Use a balanced fertilizer in spring and organic mulch around the plant.

8. Should I remove flower stalks?
Yes, removing flower stalks ensures the plant focuses energy on growing stalks.

9. Can rhubarb be grown in containers from seed?
Yes, but use a large container with nutrient-rich, well-draining soil.

10. How long do rhubarb plants last?
With proper care, rhubarb plants can produce for 10-20 years.

Conclusion

Growing rhubarb from seed is a rewarding and cost-effective way to add this versatile plant to your garden. Although it takes a bit longer to establish than planting crowns, rhubarb grown from seed can be just as productive and hardy. By following this guide, you’ll set your rhubarb plants up for success and enjoy bountiful harvests for years to come.

Start growing rhubarb from seed today and enjoy the satisfaction of cultivating your own homegrown crop!