I have a 30 year old Pyracantha hedge along the side of my house, which we keep nice and tidy. Over the last few years, a bramble has taken hold, the roots of which are located between the hedge and my house. I've tried various weed killers, but if I get some of them on the Pyracantha, it kills of the localized leaves yet doesn't seem to do anything with the bramble. We can't get to the roots, as they are at the back of the hedge against the house. I have been recommended to use Roundup, but I am concerned this may also kill my Pyracantha. Any ideas?
Certified GKH Gardening Expert
You can use Round-up, but only in a very localized fashion. Cut the bramble back as best you can and then paint the fresh cuts with Round-up. The bramble will suck the Round-up into its roots and this will go a long way to killing the roots. You may have to repeat 2-3 times, but every time you do it, it will weaken the bramble.