How to Stop English Ivy

English Ivy loves to grow in western Oregon.  It has been destroying habitat here for at least the last 40 years. Once ivy gets started, it will cover the ground so thickly that native plants get smothered out.  How does it get started?  Well, sometimes people still plant it on purpose, but at least you can’t buy it anymore.  In 2010, finally, the state of Oregon designated English ivy (Hedera helix) as a Class B noxious weed, meaning its sale, transport, and propagation are prohibited.

But ivy is still being transported and propagated by birds.  Birds eat the berries and poop out the seeds.  However, English Ivy will only flower and make berries when it climbs up a tree (or anything else it can climb).  Hardly ever will it make flowers and berries on the ground.  So, if we can keep it from climbing, we can really slow the spread.  Another reason to keep it from climbing trees is that eventually it kills the trees.  The ivy leaves will smother the tree leaves and the weight of the ivy can make the tree fall down.

It doesn’t take much time to kill the ivy that has climbed a tree.  All you have to do is cut through all the ivy vines all the way around the trunk so that the ivy is no longer connected to the ground.  It is best to cut a section out of each vine (an inch is enough) so that the ivy cannot grow the cut back together.  For thinner vines, use clippers or a lopper.  For thicker vines, use a pruning saw, reciprocating saw, or small chainsaw (some ivy vines are more than 4 inches in diameter!).  It can take several months for the ivy above the cuts to die, but it will die.  It is very satisfying to spend 20 minutes cutting old growth ivy on a tree trunk and later see all that ivy dead.   Cutting ivy on tree trunks can be done at any time of year.  We usually bring our tools when we go camping at the coast and spend some time cutting ivy on trees in campgrounds.

If you want to pull ivy on the ground, it is best to do that work in the winter while native plants are dormant.  All the ivy that is pulled up needs to be put somewhere off the ground so it will dry up and not re-root.  We have tried composting it, but that did not work.  A ring knife (aka safety knife) is very handy for cutting ivy vines while pulling it off the ground.