Western Erythronium Species From Seed
by Louise Parsons
 Erythronium seed pods are distinctively "three-cornered" or rounded. The top of the pod opens when the seeds are mature. The seeds are amber-brown when ripe. They look like plump, slightly elongate, sesame seeds |
 Erythronium hendersonii, my favorite, does well in a cool partially-shaded rock garden. It does not require scree soil, but needs good drainage. |
When to Plant Seed. The seeds of Erythronium oregonum, hendersonii, grandiflorum, and revolutum can all withstand some dry storage. In fact they tend to immediately rot upon planting if not allowed a drying period of a few weeks. However their viability and speed of germination is diminished with the typically prolonged dry storage that extends into the winter in a regular seed exchange. The seed is best planted in the early fall in damp gritty compost or seedling mix potting soil with some mineral soil added. Here in Oregon, I plant seeds in September, when the nights are getting a little cooler. Until you are ready to plant, store the seed in a cool dry place. It does not require refrigeration --just don't let it roast somewhere.
The foliage of E. revolutum is beautifully patterened in early spring.
Blooms are a clear, rich, pink.
Planting the Seed. Since initial growth and "bulb-building" will be slow, expect to keep seedlings in the same pot for at least two years. Thus soil should be fresh, sterile, and "complete", ie. no "soiless" potting mixes unless you add grit and sterile loam or worm castings. The soil should also have some real mineral goodies such as sand, grit, or pumice. Seed planted in the early fall will germinate in the spring. Even with viable seed thus planted, germination can be staggered or delayed for a full year –another reason for sowing in a generously-sized pot. You do not need to handle the seedlings, just carefully place the whole lot on into a larger pot with some fresh soil every couple of years. In fact it is best not to handle the tiny "bulbs" directly until you are ready to plant them out or into individual pots or planters for bloom.
 E. hendersonii sprouts in a generously deep, six-inch, pot. It is OK to sow them thickly. And no need to handle the new babies: I just transfer the whole lot into a larger gallon pot with fresh soil in the earliest spring. A top-dressing of clean grit prevents moss buildup. |
 E. 'White Beauty' |
The seedlings look like grass for their first season and should be kept moist during growth. Very weak or no fertilizer is best because buildup can be a problem. Western erythronium species are native to areas with dry summers and will go dormant during the high summer. However they should not be allowed to desiccate completely, even when the grassy top growth dies down. When dormant, keep cool and barely damp. Be sure to keep the pots out of hot sun, even a few moments of sun can heat soil excessively in those plastic pots. Like lilies, the tiny "bulbs" may tend to pull themselves down to the bottom of the pot. The third season, more characteristic broader leaves may appear and sometimes blooms, but bloom is more typical in the fourth or fifth season. The little "dog's teeth" can be planted out when dormant in the third or fourth year. Do not give up, depending upon conditions, it can take up to seven years for bloom!
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 E. hendersonii. As the day warms and dries out, the flowers recurve gracefully. |
Planting out Erythronium
Erythronium hybrids. These grow like cabbages here and are offspring from E.
tuolumnense
If you live in an area of high summer temperatures and/or rainfall, try to choose a location where the soil will stay a little cool and dryish: spring sun and summer dry shade is ideal. They can withstand moderate tree or shrub root competition. Erythroniums do well under deciduous trees such as Japanese maples --and like the maples, they require good drainage. This allows them some spring sun for good bloom, yet provides shade during the summer. If you plant them under conifers, it is best to place them near the outer area, where they will receive better light and winter rain. With good drainage, any decent soil type will do. A rockery with summer shade is equally ideal, as is a deep stone planter that can be given shade. Pot culture is fine, but care must be taken to see that the pots do not get overheated. With time they will pull themselves ever deeper into the ground, but will also make plenty of offsets that will bloom. With a proper setting, they are very long-lived. I once found E. oregonum under excavation on a construction site off Skyline drive in Corvallis with bulbs that were eighteen inches deep, yet they were blooming heavily. I convinced the dozer operator to replace them and they bloom today, over ten years later. Bloom time here in Oregon is March through mid-May, depending upon elevation.
Update: recommended reading! The chapter, "The Genus Erythronium" by Molly Grothaus in Bulbs of North America, published by the North American Rock Garden Society and Timber Press, 2001, ISBN 0-88192-511-X
Among many benefits of membership in the North American Rock Garden Society is the opportunity to purchase this and many other fine specialty gardening and hort books at a substantial discount.
 Blooms are downfacing when the weather is cool or rainy |
 E. 'White Beauty' |
Updated 12/19/03 with new photos