My plums sure have taken off like gangbusters. These were planted in the spring of 2015 and most are 7ft tall. I don't have the best soil conditions on my property so I'm quite happy with the growth!
It sure is and worth the time and expense. I received cost share on the weed mat from our local NRD. I was a bit worried that we might snap quite a few of the plums off as they were about 3 feet tall and we planted them first with a 3pt planter then came back over and laid the lumite tight over top of them. I didn't want to cut huge holes in the fabric either for fear of dealing with more grass/weeds choking out the seedlings so I was careful when pulling the whips back up through the slits. I think we maybe snapped all of 3-4 off but they continued to grow.