It's so hard to throw out gardening magazines. Each has info that "might come in handy some day." So I'll post here and Google the archive when the question next comes up.
'Organic Gardening', June/July 04 has the following:
"Plants have a longer-than-average juvenile period and sometimes fail to bloom as expected....Juvenile plants should be fertilized only once a year...fertilizer with a balanced NPK ratio. Established wisteria needs little fertilizer...water only during drought and fertilize if the foliage yellows and new growth is poor. ...produces blooms on old wood...don't prune heavily in winter and early spring...prune after blooming (get a book for specifics). W...needs at least 6-8 hours of full sun to bloom best."