do you currently have it in conditions that it doesn't like...? I would think two years would be a great start for establishing a good root system. the upper part of the stems should be in full sun and the roots need to be kept cool, by other plants or a fence or something. we use hostas planted around the base of our superba to keep its roots cool. we also fertilize ours with diluted organic 5-1-1 fish emulsion. its EXCELLENT for putting on growth prior to blooming. we also work in alfalfa meal into the surrounding soil once it starts putting on new growth. We've had our "Superba" not even two years now and its light years above and beyond any clematis ive ever owned! growth is so vigorous and the stems have already reached the top of the trellis its growing on and its about to take over! not that thats a bad thing, the more vigorous the better, the more flowers the better!! im just saying its not going to leave much room on top of the fence for the two other clematis plants (Henri & Gravetye Beauty) trying to catch up! ha
the pic below was taken on July 2nd of last year. it had only been in the ground 18 months at the time!
