I want to plant a thorny security hedge to prevent badguys from climbing over a 4-foot-high yard wall. The length would be about 15 feet. I know about firethorn and blackthorn and their nasty thorns (which I want), but they aren't native. I have a full west unobstructed exposure. Any suggestions? Thanks.
While your interest in using a native is a good thing, there aren't native plants that would really fill the bill and do what you want here.
We'd suggest that the firethorn (pyracantha) is a good choice.
It's not native, that's true, but it is not considered an invasive plant which spreads all over.
Thanks. I was leaning to pyracantha anyway because it has the added advantage of being a very attractive plant. I want a hedge because my yard is pretty small, and the Fort Apache--style wooden palisades favored around here can be claustrophobic.
Yes, pyracantha does make an excellent hedge. The following is a publication from Clemson, even though this publication is not from Maryland it contains some good information. Look for disease resistant cultivars like Apache and Mohave. You should be able to find them in a nursery in MD.