A Week of Weeds - Ivy

Ivy (Hedera helix) ascending and carpeting

 Controversial, I know, because this is a "native" plant that affords food and a home to many life forms. But you can get too much of a good thing.  We have a local nature reserve which is the remnants of the wooded land in this part of Edinburgh, the bits that were found to be unsuitable for housing due to rough terrain and access problems. It is a valuable conservation area but overrun with ivy.  Reputedly it takes 30 years for ivy to reach the top of a host tree. Well thirty years have passed:

On the plus side ivy flowers late in the season, from September through to November. This helps sustain a whole host of insects in the run up to winter. It is also a refuge for birds and small mammals.  But boy does it take over.  The danger to trees is more one of increasing their wind profile rather than strangulation as ivy takes up water direct from its own roots.  At ground level it deprives competing plants of light as well as water and elbow room. 

Walls or trees its all the same to ivy

 The term monoculture springs to mind, whereas biodiversity is the sign of a thriving landscape.  Human intervention may be undesirable from a nature conservation point of view but the landscape which undeniably has been formed by both nature and man, has become a playground for this successful plant to the exclusion of many others.  It's status as a native (and consequential large number of benefiting fauna) ensures that war has not been declared on it, as it has for Japanese knotweed, for instance.  It's a bit of a bind!