Although the native English bluebell and the larger Spanish bluebell are often grown in gardens, they can multiply and become a nuisance, requiring control. Spanish bluebells can also hybridise with the native form so are best controlled in gardens close to woodlands where the English bluebell is growing.
What are the species of bluebells?
While many gardeners welcome the native bluebell (Hyacinthoides non-scripta) in their gardens, it can become a nuisance. The larger Spanish bluebell is also pretty, but can become a problem too, not just because of its spreading habit, but also due to its ability to hybridise with the native English form. The hybrid forms could potentially oust the natives and we advise against growing Spanish bluebells in rural gardens.
The difference between English and Spanish bluebells
Flowers of native bluebells are narrowly bell-shaped, with straight-sided petals, deeply curled back at the tips. The majority of flowers droop from one side of the stem. The anthers are creamy-white and the leaves narrow, usually between 0.7-1.5cm wide (about ¼-¾in), although occasionally up to 2cm (¾in).
Spanish bluebell and hybrid
The bell-shaped flowers of Spanish bluebells and the hybrids between this and the English (known as H. × massartiana) open more widely than on English bluebells, with the petal tips just flaring outwards or curling back only slightly. Some flowers may droop from one side, but most are arranged all around the stem and held more erect. The anthers of Spanish and hybrid bluebells are usually pale to dark blue, and the leaves are wider, up to 3-3.5cm (about 1¼in) across.
Bluebells can spread rapidly, sending out underground runners, on the end of which new bulbs form. They also seed freely and often hybridize when grown together.
The bulbs can also persist in garden compost heaps.
Plants that out-compete other more desirable plants or simply invade half the garden are classed as weeds and require control.
It is best to dig out bluebells while they are in leaf, as the bulbs are almost impossible to find when the plants are dormant:
- Loosen soil around the bulbs to a good depth and remove all the bulbs and underground runners
- Where shoots appear from underground runners among clumps of low-growing garden plants, carefully insert a garden fork to its full depth close to the shoot. Work the handle of the fork to loosen the bulb then, grasping the shoot, gently ease the bulb out of the earth
- Choose moist soil conditions to carry this out and firm in disturbed garden plants
Caution: do not dispose of bulbs by adding them to the garden compost heap and never discard unwanted bulbs in the countryside. Consign them to a black plastic sack and leave for a year before composting.
Bluebells are strongly resistant to weedkillers and it appears that no garden weedkiller will kill them or even check their growth.