I know what you mean. I just had to have a deep blue morning glory that was covering an arbor at a local nursery. I ordered two because they were out of them. The clerk asked, "You mean one, don't you?" I said no, that I wanted two to plant on either side of a trellis. He assured me that one would be more than enough, but I insisted on two. My neighbors on either side of my garden wish I had listened to him. All three of us are constantly yanking them out. Wherever the vine touches the ground, another plant grows up and over the shrubs and trees.