Eranthis (winter aconite)

 

They are the earliest yellow flowers and make a perfect late-winter carpet beneath trees and shrubs. Any soil, including clay, is suitable as long as it is moderately well-drained and does not dry out in summer. It makes a lovely early spring show in combination with Snowdrops. A mulch of  leaf-mould or decayed manure once every two years in the autumn will insure more and finer flowers. Soaking the black tubers in water 24 hours prior to planting helps to increase the percentage of flowers the first spring. Plant 5cm deep, 8cm apart.