Winter Care of Wisteria
This is my second winter for my wisteria & I am not sure what I should do with it before winter. It grew a lot this summer & I don't know whether I should let it be & go dormant or trim it back. What type of mulch should I use?
Mulch the soil with shredded bark or woodchips to moderate temperature extremes, conserve moisture, and reduce weeds. No additional mulch is needed for winter survival for Japanese wisteria (Wisteria floribunda) growing in zones 4 or 5 to 9, Chinese wisteria (Wisteria sinensis) in zones 5 to 8 and Kentucky Wisteria (Wisteria macrostachys) in zones 4 or 5 to 8 or 9.
Wait until late winter to prune the plant. Hopefully you cut the plant back to 30 or 36 inches above the ground at planting. This encourages side shoots to develop. The strongest two should have been kept and trained over the arbor or trellis. This year, prune back the main stem to about 30 inches above the upper most side shoot. Save two additional side shoots to help cover the arbor. Shorten the side shoots by one third. Repeat this each year until the support structure is covered.
Once established, prune in summer to help control growth and promote bloom. Side shoots and laterals (stems growing off the main stems) are pruned back just above the fifth or sixth bud from the main stem. In late winter these same branches are pruned back to within 2 to 3 buds of the main stem.
If you haven't done any pruning, you may need to modify the pruning steps. Gradually establish the structure over the next few years. Northern gardeners should consider using the flower bud hardy Kentucky wisteria when adding new wisteria plants to the landscape.