Wisteria can occasionally be a little slow coming into flower, especially where the soil is fertile.
Here, the plant seems to put all its energy into producing stem and leaf growth. To encourage flowers and to create a strong canopy, carry out regular pruning. From the time of planting select one strong top shoot to train vertically and two or three side shoots to train horizontally. In late winter cut back the vertical to within 60 cm of the highest horizontal and cut back the horizontals by one third. In spring and summer you then train the most vigorous top shoot vertically and the side shoots horizontally.