The normal flowering pattern of a wisteria vine is March however it at times also flowers in July but this bloom period is short owning to rising temperatures. Wisteria vines can be propagated easily through air layering. Mr. Khalid based is Lahore has the same specimen of Wisteria which he sells at reasonable rates and can be contacted at 0333-4371711.
The air layered ones propagated by Mr. Khalid take 3 years to flower if grown in a site having full sun with good drainage.
The wisteria he offers tend to flower within 3-4 years if planted in full sun in the ground. His wisteria's are guaranteed to flower whereas the wisteria's offered by Lahore Nursery do not flower for 10-12 years. Indeed he's a very nice guy who sells plants at very reasonable rates. He also has a fragrant variety of Clematis (Sweet Autumn) whose clusters of white flowers flower around September and this variety flowers profusely.
Thanks. Now that u mention lahore nursery. I m more disturbed by how they run their business than what they sell. I recently visited them a few times and as a test case each time inquired about the price of the grafted prunus nigra that they got(local grafting). The salesman with white hair n moustache(name?) once quoted 1500/plant. Then at another occasion few days later 2500/plant. Ali, who is there as well quoted 1000/plant. At another occasion Ali tried to sell a murraya penniculata (local, bigger leafed) for 6000 calling it Australian marwa. And the next day the white haired salesman said its for 1000. I have come to distrust all of these gentlemen incl the owner haji Sb