There are various types of buddleia but for the purposes of this factsheet we shall focus on the most common type which is Buddleia davidii. This non native plant is extremely popular to gardeners due to its bright coloured flowers and its attractiveness to butterfly’s; which is said to have a ‘magnet’ like effect in drawing them in. Within the garden, if well managed, this plant causes not significant problems however Butterfly bush has escaped the garden and is becoming a common feature within waste grounds, roadsides, alongside railway lines, urban areas and quarries.

This spread has occurred due to its ability to thrive in harsh environments that have very limited nutritional value; therefore Butterfly bush has been found on top of bridges and high buildings, it also can grow to heights of 3 metres. Each plant can produce an amazing 3,000,000 seeds which are distributed in the wind and can germinate with tiny amounts of soil and moisture. These facts present a serious risk to structures were seeds germinate, grow and cause cracks which allows water to enter. This creates a freeze thaw process which causes significant structural damage; once the plant has taken hold it is difficult to eradicate due to the amount of seeds it produces and their ability to germinate and grow in harsh conditions.

Appearance

Flower

Narrow, upright spikes of deep purple (most common), pink, yellow or white flowers, each spike 7 to 20 centimetres long, individual flowers small with four petals. This plant produces around 3,000,000 seeds per plant and thousands per flower.

Twig

Moderately stout, very angled twigs, initially green, later turning light brown, large white pith, small buds.

Leaves

2- 7 centimetres with finely serrated edges.

Butterfly Bush Treatment and Control