How do you prune Wisteria in windy Wellington?

There are plenty of resources out there about pruning Wisteria and some established rules/truisms. Prune back to 2-3 buds in winter to encourage flowering, prune to 5-6 buds after flowering for a repeat show etc etc.

Here’s what I’ve found in my garden in Lower Hutt, Wellington, New Zealand. My wisteria is growing over a pergola in a position where it gets the early sun and a smattering of afternoon summer sun. Windy as Wellington is prone to be. Not ideal for a plant which thrives in a sunny situation but it is a position in which I’ve been able to promote strong growth and decent flowering.

How have I achieved that? Well, it doesn’t take much to get strong growth from a Wisteria! They’re vigorous beasts. However the flowering has proved to be a trick. I prune after flowering and find that I get a repeat flowering and/or the formation of solid flower buds for the next year. Winter pruning just seems to encourage the vigorous habit, produce a whole bunch of excess growth and risks pruning off flower spurs by mistake. So prune in winter and I get a plant that goes “Yahoo!” and takes off in all directions for the other three seasons.

So, in winter I restrict myself to pruning off dead and damaged wood, cutting back excess growth including that spreading across my roof and through the guttering and pruning back some side shoots to 2-3 buds. I take off some growth from the main stems for form and shape but other than that I mostly leave it alone other than folding some shoots back into the vine. I’m careful not to make it top heavy though because I’ve learnt from experience that Strongs which we get at regular intervals can take a top heavy plant and severely knock it about. I made that mistake with a Lemonwood which I was pruning for shape, took off the lower branches and returned home on a windy day to find it blown right out of the ground!

Late Spring/Summer after flowering is when I put in the most effort. Cutting back growth to 5-6 buds, and removing spent racemes.

This approach works for me at my place and is the result of years of experimentation. It’s a great time-saver too as I don’t have to spend hours in winter pruning back the plant into fine shape consistent with generally accepted wisdom.

If you’d like more information on pruning Wisteria please see https://www.rhs.org.uk/plants/wisteria/pruning-guide