British Columbia: Help with Wisteria

I need help. I have just bought my 4th wisteria and planted it yesterday. I built an arbour the summer of 2008 and planted two one gallon wisteria from Triple Tree Nursery in Maple Ridge - one on either side of the arbour - that fall. One has not grown at all and the other might have gained 8 inches in height. Both plants produce leaves in the summer. I have heard such stories of and seen wisteria that have really taken off - but not in my garden. I planted each in well prepared holes - with a touch of bone meal and compost. I water the wisteria by hand in the summer. I bought a five gallon wisteria last week from Art's Nursery in Langley - hoping to get a jump on the one gallon fellows. I planted it in a well prepared hole - bone meal and well rotted manure and compost mixed into the soil. (The forth wisteria rotted off at the base - planted under a hydrangia - too shady - live and learn). If all three of the surviving wisteria take off I may be in a bit of trouble but that does not seam likely if history keeps repeating itself. Any help or suggestions out there!!!!!!

 

>I planted it in a well prepared hole - bone meal and well rotted manure and compost mixed into the soil<

That might have something to do with it.

Amended backfill has markedly different characteristics
than surrounding native soil; it is more porous and water will wick away to the finer-textured native soil.
In the summer, moisture within the planting hole will be depleted by the plant but not replaced by water
held more tightly in the native soil. This results in water stress to the plant unless the planting hole is kept
irrigated, a costly and often unrealistic practice. During wet seasons water will move quickly through the
amended soil only to be held back by the more slowly draining native soil. The resulting bathtub effect,
wherein water accumulates in the planting hole, floods the roots and eventually kills the plant.

http://www.puyallup.wsu.edu/~linda chalker-scott/Horticultural Myths_files/Myths/Amendments.pdf

Note: Ignore the second paragraph, with the silly bit about roots exploding into the amended backfill, only to later turn back(!) when they reach the unfriendly planting hole walls

Same site also has a PDF on bone meal.