Q & A: What to do with my silly Wisteria arch?

We're starting a new, occasional column where we attempt to answer questions sent in to PSG. And when I say "attempt" I mean that if we don't know the answer we'll ask our panel of experts. And when I say "panel of experts" I mean my dad, a Renowned Horticultural Professional who has Written Books and Stuff. Could be fun, eh?

Question: "We have a yard that is overflowing with green and my husband and I have historically been overwhelmed by taking care of it. We are planning to moderately redo our backyard so that it's less high maintenance for us. The original owner of the house was a sort of putterer, and he constructed this very silly archway out of metal pipe, and put wisteria, grapes and morning glories on it. Fast forward at least 50 years, and we have a tangle of beautiful vines that grows out of control.

I've been told that wisteria is very valuable and wanted to ask your opinion. I don't know where else to turn and know that you are an expert. Is this something I could sell? Do you have a recommendation for how to handle this?"

- Meredith in San Francisco.

Answer: A mature Wisteria that flowers (this can take decades) is valuable to the owner of that plant - they're very pretty as you know! But the reason Wisterias are expensive to buy is that they must be grown for many years before they bloom, which is an added cost to the nursery.

Sadly, Wisterias do not transplant well, so moving a large/old one that's attached to a structure is a huge endeavor that is likely to fail. Also, similar to large palm trees they're likely to cost more to move than they are worth in general. (The huge cost of buying a big palm tree is not usually a factor of their intrinsic value, but the great expense of moving them around!)

My suggestion is to enjoy your Wisteria, and if need be hire a landscaper to remove the arch and replace it with something nicer (this may or may not be possible). If you can't live with the arch or the mess or the expense, whack the entire thing down and start afresh!

Additional answer: Great question and on this side of the pond (UK), it is a very common one.

I am assuming you are growing an Asiatic wisteria (W. floribunda from Japan or W. sinensis from China ) as these are the best in gardens. The first thing to find out is: does the vine bloom well and are the blooms up to scratch? In the oldendays, wisterias were sold as seedlings and many of them were not garden-worthy. This was largely because they hardly produced any flowers or those they produced were chunky and drab and not the long elegant trails we love. Nowadays the best kinds are grown from cuttings and some have flower stems up to a yard long.

So if it’s a good’un why not prune it back maybe over two seasons then keep it in check by shortening back the long new growth in early summer so that it concentrates on making flowers at the base of the new growth. A high potash feed would help it flower better. But maybe you want an easier life and then you might be better cutting it off at ground level and planting something more restrained.

- A Renowned Horticultural Professional

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If you'd like to submit a question to our Team of Experts, please send it to the Head Gardener in an email. Please note that this service is free, and the advice is worth probably at least as much as you paid for it! Should anyone disagree with these opinions please add your comments below and between us all we can help our dear readers.