Erythronium - variously called Dog's Tooth Violet and Trout Lily are just perfect for dappled shade or woodland use. It gets the nickname Dog's Tooth Violet from the shape of the long pointed canine-like bulbs. There are several types generally available for the gardener, with a wide selection with the specialist bulb seller. Not too often seen in gardens, they should not be considered as being rare or hard to grow.
Planted beneath some overhanging deciduous shrubs or at the base of a large tree - such as an Oak - they will never fail to please in late march for a few weeks, and thereafter with some interesting light green foliage. The bulb plants soon forma clump, and will also be good groundcover, for they have good foliage at the early part of the year - smothering new weed seedlings before they get a chance to establish.
Whilst Erythronium are at home in woodland situations, they are also amenable to full sun - especially in a slightly damp environment. They also naturalize quite well in meadows, though not in garden lawns, for the foliage and often the flowers persist well into the summer, and will not tolerate being mown off.
The top image is of Erythronium californicum 'White Beauty'
It is important that the planting area is not allowed to dry out completely in the summer, for Erythroniums need moisture even when seemingly dormant.
The same goes for prior to planting or at purchase time. They should be kept in moist peat or other medium until planted out in the Autumn.
Erythroniums are often planted too shallow. They should be planted no less than 10cm - 4in deep, and not until Autumn sets in proper. The planting depth also helps to ensure that the bulbs have access to soil moisture in the summer and ensuing short dormancy period.
Lower image is of Erythronium tuolomnense.
When planting, it is a good idea to dig a sizeable hole for the bulb and surround it in the planting hole with peat based multi-purpose compost or other suitable planting compost, but not too rich or fresh from the compost heap.
A lightly shaded place is ideal, but as above a protective moist meadow will also suit. Good fertile soil, that does not become waterlogged.
Erythronium - Dog's Tooth Violet - can be lifted and divided right after flowering, and not allowing them to dry out at any stage. carefully tease the bulb clumps apart and replant immediately - watering well in.
No problems other than slugs wanting the succulent foliage - and shelter. The other problem is a cultural problem in that the growing and dormant bulbs should not be allowed to completely dry out!
All grow in slowly spreading clumps, with flower heights to 30cm - 12in max.
Erythronium dens-canis is perhaps the best known - though not the most commonly planted Erythronium. One claim to fame being that it has markedly upturned pink-lilac flowers, and rather attractive mottled foliage - purplish blotches.
Erythronium californicum - again has upturned flower petals, but this time creamy white with purplish base to the flowers. The foliage is slightly 'marbled' rather than mottled - and pointed leaves.
Erythronium californicum 'White Beauty' is one of the most spectacular - creamy white flowers with yellow centres and petals whilst upright, are spreading - giving a wide bell appearance. Very attractive.
Erythronium 'Pagoda' - gets its name from the multi-stemmed and flowered pagoda shape bloom of golden yellow. This variety has very good foliage being bright glossy green and bronzed mottling.
Erythronium tuolumnense is one of the quickest spreading types and good for ground cover in woodland garden or beneath shrubs.