Growing Rhubarb from Seed for Rare or Heirloom Varieties
While most gardeners propagate rhubarb by dividing crowns, starting from seed opens up a world of rare and heirloom types. It’s affordable, rewarding, and the best way to expand your crop with varieties you can’t find in stores. If you’re patient and eager for genetic diversity, here’s how—and why—to grow rhubarb from seed.
Why Grow Rhubarb from Seed?
- Access to rare or heirloom varieties: Seed catalogs, seed swaps, and heritage growers offer options not found as crowns at nurseries.
- Genetic diversity: Every seed-grown rhubarb is a little different. Unique colors, flavors, vigor, or resistance can emerge.
- Large plantings, low cost: Seeds are much cheaper than crowns—grow a big patch or “trial bed” for pennies.
- Fun experiment: Great for kids, schools, and curious gardeners.
When to Sow Rhubarb Seed
- Indoors: Late winter to early spring (January–March).
- Direct sow: After last frost in spring (less reliable germination outdoors in most climates).
How to Grow Rhubarb from Seed—Step by Step
1. Select Fresh Seed
- Use the most recent harvest for best germination (seed loses viability fast).
2. Soak & Prepare
- Soak seeds in water for 6–12 hours to soften the coat.
3. Sow Indoors
- Plant in trays or pots, 1cm deep, spacing seeds 2–3cm apart.
- Use a rich seed-starting mix, keep at 18–22°C (65–72°F), and maintain steady moisture (not soggy).
- Expect germination in 7–21 days.
4. Grow On
- Once seedlings have two true leaves, pot into individual 7–10cm (3–4”) pots.
- Keep indoors until after the last frost, then harden off for 1–2 weeks outdoors.
5. Transplant Outdoors
- Set young plants in prepared soil (see bed guides) at least 90cm apart.
- Water well, mulch, and weed regularly.
6. First Harvest
- Do NOT harvest the first year, and only very lightly in year two.
- By the third year, harvest as with crowns.
Heirloom and Rare Varieties to Try From Seed
- ‘Glaskins Perpetual’: Excellent color and long season—great for seed propagation.
- ‘Victoria’, ‘Frambozen Rood’, and several Russian/Scandinavian heritage lines—ask seed exchanges and rare plant societies.
Tips for Success
- Mark different varieties carefully; save seeds each season for unique, adapted types.
- Keep the best performers for sharing or replanting, and compost underperformers.
- Be patient—seed-grown rhubarb takes up to 3 years for full harvest.
Wrapping Up
Growing rhubarb from seed isn’t instant—it’s an adventure. For gardeners seeking rare flavors, bold colors, or to keep heirloom varieties alive, it’s richly rewarding. With time, you’ll have a patch that’s as unique as your gardening journey.