One of the best plants for butterflies, moths and bees at this time of year has got to be Buddleia. There is, however, a dark side to this plant and it is very important that homeowners and landowners alike understand how to use it successfully without leading to negative impacts to our British countryside.
Buddleia species provide fantastic nectar resources between June and October throughout Britain but, as the name suggests, these plants weren’t always present within our countryside and were, like a lot of flowering plants, bought over to the UK from Asia in the late 19th Century.
Their importance as a nectar source stems from the amount of nectaries present in each flowering plant. The availability of sugars as nectar encourages a great variety of invertebrates to feed on these bushes, at a time when our native resources may not be as available or might well be over competed. A study funded by the UK Insect Pollinators Initiative called the Agriland Project (a partnership in pollinator research with Bristol, Leeds and Reading universities, DEFRA and CEH) discovered that along with other introduced species, buddleia plants have one of the highest densities of nectar available.
So whats the problem with Buddleia? Although these plants are great for wildlife in our gardens, once seed dispersal moves them into native habitats like grasslands, woodlands and areas of scrub these species soon over shade and out-compete our native vegetation, changing the habitat dynamics and potentially leading to eradication of some sensitive species.
So what can we do to stop the spread into the wild? The best method to reduce the risk of Buddleia escaping your land is to remove the flowering heads once flowers start to die back, this will remove the seeds before they are naturally dispersed. Further pruning in October will encourage Buddleia to regrow with greater density in the spring, this is recommended as long as the seed heads can be managed easily.