Erythronium grandiflorum

Erythronium grandiflorum, commonly known as the Yellow Avalanche Lily or Glacier Lily, is native to west North America. In its native habitat it grows in subalpine meadows and woodland clearings and flowers as the snow melts. It is perfect for growing a shady spot in moist but well-drained soil.
This rarely offered species has bright, golden yellow tepals, and is very curious from a botanical point of view as the stigmas are 3-lobed. The anthers are usually white or yellow and sometimes red or black and the foliage is not mottled but bright green.

Erythronium grandiflorum is one of the largest of the genus, the bright green leaves that appear in pairs are wavy-edged and up to 20cm (8in) long and 6cm (2½in) broad. The flower stalks may reach 30cm (12in) tall and each flower stem has up to ten golden yellow, nodding, star-shaped flowers with reflexed petals. They bloom in early spring, the broad leaves appear first, followed by the wiry flower stems which come through from the middle of the leaves. After the blooms fade the plants mysteriously vanish until next year.

Is there a part of your garden that's slightly on the wild side, a shady or woodland area that isn't carefully manicured and frankly, you like it that way? Erythronium, commonly known as Dog Tooth Lilies are perfect for these spots. All Erythronium have good interesting leaves and associate well with Dicentra, Trilliums, Epimedium and Anemone nemorosa. They also make excellent shade partners for Hostas.
The flowers of Erythronium are pollinated by bees. They are an important nectar source for bees as they, along with other early spring flowers such as cyclamen are one of the first sources of nectar.

• Awarded the RHS Award of Garden Merit
  Erythronium grandiflorum has been awarded the Royal Horticultural Society’s Award of Garden Merit (AGM).

Position:
Erythronium require a moisture retentive, fertile soil. They do best when planted under trees and shrubs, in as near to a woodland setting as possible. They like cool humus-rich growing conditions in the spring with a period of drier dormancy in the shade in summer. They tolerate most pH but dislikes dry soils. They dislike being moved so try to choose a spot where they can be left undisturbed.
If you want to plant them in containers use a John Innes compost rather than a peat based compost. They will be fine in this and should only be re-potted when it is absolutely necessary.

Sowing: Sow as soon as possible at cool temperatures.
Growing from seed is quite straightforward, though you may have to wait quite some time before the first flowers appear, typically 18 months to two years.
Sow the seed thinly so that it will not be necessary to prick them out for their first year of growth. Give an occasional liquid feed to the seedlings to make sure that they do not become nutrient deficient.
When the plants are dormant, pot up the small bulbs putting 2 to 3 bulbs in each pot. Grow them on in a shady position in the greenhouse for another year and then plant them out into their permanent positions when they are dormant in late summer.

Cultivation:
Erythronium seedlings and bulbs should not be allowed to dry out and should be planted point up 10cm (4in) deep and 12 to 18cm (5 to 7in) apart in a cool, well-drained position where it will not become too sun-baked in summer, such as under shrubs and trees, whose roots will take away excess moisture.

Division:
Divide congested colonies in the summer, May to June as the leaves die down. Many Erythronium have a habit to divide freely to form clumps containing many small non-flowering bulbs. To remedy this, lift and divided congested colonies and replant the bulbs singly about 10cm (4in) below soil level.
Larger bulbs can be replanted immediately into their permanent positions, but it is best to pot up very small bulbs and grow them on in a shady position in a greenhouse for a year before planting them out when dormant in late summer.

Plant Uses:
Shade and Woodland Gardens, Containers

Origin:
Erythronium grandiflorum is native to western North America from to British Columbia and Alberta south to New Mexico and California, though it has not been reported from Arizona or Nevada. It can be found in subalpine mountain meadows, slopes, and clearings. This bulbous herbaceous perennial flowering plant is in the family Liliaceae.
In its native habitat the bulbs of this plant are eaten by bears and other mammals. They are the preferred food of the grizzly bear.

Nomenclature:
The genus name Erythronium is a corruption of a Greek name taken from an ancient Greek plant name erythronion, also from erythros, meaning ‘red’, and derives presumably from the reddish colour of the leaves and flowers of some species
The species name grandiflorum simply means large-flowered.
It is known by several common names, including Yellow Avalanche Lily, Glacier Lily and Dogtooth Fawn Lily.