Yes, you can grow epimedium from seed, but it is slow work. The seedlings take 3 to 4 years to bloom for the first time. Epimedium seed propagation needs cold treatment and patience to work well. Most gardeners pick division over seed because the results come much faster in your own bed.
I tried seed propagation once in my third year of growing this plant. I sowed 30 seeds in a cold frame in July. By the next spring, only 8 had sprouted for me. By year three, just five plants had made it to a useful size. In my experience, most gardeners give up on seed for this reason alone.
Division gives you bloom-ready plants in 1 to 2 seasons, not years. A clump split in fall will flower the next spring with no fuss. When I divide a healthy clump, I get four or five new plants right away. Each one is a copy of the parent, so the leaves and flowers stay true to the cultivar I love.
If you still want to try seed, the first step is to collect fresh pods. The pods ripen in early summer about six weeks after the flowers fade. The pods turn brown but should not split open yet. Watch your plants close in June and July. The seeds are best when sown right after you pick them off the plant.
Epimedium cold stratification is the key step that breaks seed dormancy. The seeds need 8 to 12 weeks at about 40°F (4°C) to wake up. You can sow seeds in a cold frame and let winter do the work. Or you can mix seeds with damp sand and put the bag in your fridge for the whole period.
Collect and sow
- Timing: Watch pods in June and July as they turn brown but before they split open and drop seed.
- Sow fresh: Plant seeds right after harvest in moist, peat-free compost with a thin grit topping.
- Pot choice: Use a 4 inch (10 centimeter) wide pot with at least three drainage holes in the base.
Cold treatment
- Duration: Give seeds 8 to 12 weeks of cold time at about 40°F (4°C) for best results.
- Natural method: Place pots in a cold frame outside through winter for free cold treatment.
- Fridge method: Mix seeds with damp sand in a zip bag and stash on a low fridge shelf for 10 weeks.
Sprout and grow on
- Germination: Look for tiny green shoots in spring after the cold period ends and warm days arrive.
- First leaves: Seedlings show one or two small leaves for the first few months of growth.
- Time to flower: Plan for 3 to 4 years before you see the first wiry stems of small flowers.
Iowa State Extension notes that epimediums cross-pollinate with ease. Your seedlings might not look like the parent at all. The leaves could be a new shape. The flowers could be a new color too. Some growers love this lottery effect. Others want a known plant and stick with division for that reason instead.
NC State Extension lists division as the standard way to grow more of this plant. The same source notes that seedlings are slow to bloom. I agree with this advice for most home gardeners. If you have years to spare and love a surprise, try seed. If you want plants in two seasons, divide your clump in fall.
For epimedium seedling care, move your young plants once they have 3 to 4 true leaves. Pot up each seedling into a 4 inch (10 centimeter) pot with fresh shaded compost. Grow them on in deep shade for one full year. Water them well through dry spells. Feed them with a light slow-release pellet in spring.
Plant out your seedlings only when the crown is the size of a US quarter. This usually happens by the end of year two for most pots. A small crown will struggle in the open garden bed. A bigger crown can fend off slugs and dry spells with no help. This last step makes all your hard work pay off in the end.
Read the full article: Epimedium Plant Grower's Guide
