What to look out for in April
Bluebells occupy a special place in the British psyche, arguably like no other flower. Is it the broad swathes of colour that so intensely contrast with the yellow-green of newly emerged foliage? Or is it the intoxicating smell that recalls the hyacinths to which they are related?
English bluebells (Hyacinthoides non-scripta) inspire people to visit woodlands more than any other wildflower. We talk of ‘bluebell woods’ but we never talk about ‘anemone woods’ or indeed any other type of wildflower wood. We are right to hold them in such high estimation, Britain has the largest population of English bluebells anywhere in the world.
Bluebells are often found in ancient woodland and combined with other plants can be used as an indicator species for this type of habitat. Colonies are slow to spread and their life cycle is attuned to that of native trees such as oak, birch and beech, with which they are closely associated. Consequently their fate is closely bound with the future of our ancient woodlands, which now only covers 2% of the UK.
Bluebells will grow in full sun but really thrive in the dappled shade. However too much shade, often from evergreen trees such as holly and introduced conifers, causes them to flower poorly and leads to decline Where large patches grow outside of a woodland habitat it could well be a sign of a ‘shadow wood’, a vanished wooded landscape.
Threats to English bluebells come from multiple directions: habitat loss; being trampled underfoot; and hybridisation with the non-native Spanish bluebell (H. hispanica). In 1981 it was made illegal to pick or dig up bluebells from the wild and garden centres began selling the Spanish form. This contributed to the problem of Spanish bluebells escaping from gardens into woodlands, where they produce a hybrid bluebell, H. x massartiana, which outcompetes the native species.
Where English bluebell is a rich blue – occasionally white and rarely pink – the Spanish form is significantly paler. English bluebells have narrow bells on a curving stem; Spanish ones have wider bells and a more upright habit. The hybrid form is much harder to distinguish from the native plant.
As one of the earlier flowering British plants, bluebell is a key food source for butterflies – including brimstone, orange-tip, and peacock – and long-tongued bumble bees, who are perfectly adapted to extract the pollen and nectar from the long, narrow flowers.