RHS Award of Garden Merit.
A delightful and very easy to grow plant with plenty of light-purple flowers during the spring. It clumps and naturalises with ease in a bright, partially spot (dappled shade is best) with fertile, moisture retentive soil. It does not like being dry so if your soil is prone to drying out an annual organic mulch will work wonders.
Height to about 15cm, perfect with deciduous ferns such as Dryopteris dilitata or Athyriums. These ferns are especially useful in gardens without deciduous trees as the fronds will also help shade the soil in the summer. The Erythroniums become dormant shortly after flowering so the new fern growth helps hide the foliage. Planting both increases the interest throughout the year with two very different looks!
Björn Sothmann, CC BY-SA 3.0, via Wikimedia Commons