Not really a perennial and I didn't plant it...but two plant species in our garden drive me nuts. The previous owners must have thought Kikuyu Grass would be a good idea (NOT!) it has spread everywhere and sends its huge deep runners into all the garden beds and has even "escaped" onto the verge near the road...they also planted s variety of Tecoma...it suckers everywhere and is a monster to control. My plan is to eradicate the lot, but I don't use chemicals or poisons on our land...so I'm guessing I'll be at it for a while.