Shoe's right though.
Suddenly a PI patch appeared in my front flowerbed. I cut it all the way back to the ground. It appeared again, I cut it back again.
This happened several times a year for about 5 years. I have a lot of heirlooms planted in that front bed so I refused to douse them with chemicals. I never gave the PI a chance to form more than a leaf or two before cutting it back.
It didn't appear at all this year, I figured it gave up and went elsewhere.
I think I might have won that battle.
It's like a lot of other things, if it doesn't get energy from the sun, it gives up, goes away, but it's important that it's cut back to the ground. Luckily it doesn't like me either, so I'm not usually bothered by it.
