Tackling invasive rhododendron in the south Lakes

Volunteers help clear invasive rhododendron in the south Lakes, Cumbria

Rhododendron are loved for their spectacular, bright displays but in the wrong place, they are aggressive competitors to our native species and they love high rainfall so thrive around here!

A non-native invasive species, rhododendron prevents native flora from growing due to its dense evergreen shade. It colonises an area through stem layering and by producing millions of seeds, and thanks to its 'tenacity of life', is difficult to remove, making it the bane of conservationists like our rangers.

A nasty peice of work

Rhododendron damages the habitat it invades by dominating the area. It spreads laterally through branch layering creating dense, impenetrable growth which prevents light from getting to other species. Its leaves and buds contain toxic chemicals making it unpalatable to grazing animals. These chemicals may also act as an inhibitor to the growth of competing species further adding to its domination.

Facts about this feisty flower

  • 1760s When the first Rhododendron were grown in the UK
  • 58 days How long our rangers & volunteers spent clearing it in 2016
  • Poisonous Its honey is poisonous to humans and bees

The rangers are ready and armed

Much work has been done by the rangers in recent years to remove rhododendron and improve woodland flora and bio-diversity. But the successful eradication of rhododendron requires a programme of managed removal, monitoring and control over a number years - aka Rhody Bashing!

How do we tackle them?

There are several ways to tackle rhododendron. You can pull up the seedlings by the roots, dry the roots and snap the stem; saw off branches at the base and treat the stump with herbicide; spray the leaves with herbicide where there is no risk of over-spray effecting surrounding flora or contaminating a watercourse; or use mechanical flailing.

Taking drastic action

Given our number and the location of our rhodies, plus the type of the terrain and potential risk of over-spray, our method of choice is often to cut and saw the branches down to the stump, leaving about a foot standing with a few leaves sticking up to act as a flag. This is to help locate the stump and treat it with herbicide at a later date. The cut branches are then piled up ready to be burned.