HI, my Wisteria plant is looking poor, It was planted in 2018. I have enclosed a picture to show the leaves.
Any guidance is much appreciated. we live in North York
Thank-you for contacting Toronto Master Gardeners with your question.
The most commonly planted wisteria is the widely available, Chinese wisteria (Wisteria sinensis), followed by Japanese wisteria (W. floribunda). There are also North American native species becoming available, Kentucky wisteria (W. macrostachya) and American wisteria (W. frutescens).
While generally strong-growing and vigorous, all of the above types of wisteria vines can experience problems. I am unable to make a diagnosis based on your photo, but here is some general information and a couple of sources you can check out to help you determine the exact problem.
As is often the case, the most common problems are under- or over-watering. There was a sudden hot, dry spell in the Toronto area a week or so ago, following on from a cold wet spring. It is possible that your vine was growing quickly just as this mini hot spell occurred. A good, thorough watering should revive it if this was the case. More common, however, are problems due to over-watering. Wisteria requires a fast draining soil. Excessive moisture frequently results in root rot. As well, crown gall and canker are not uncommon problems with wisteria.
Wisteria is also prone to a particular pest, the wisteria borer, an insect that attacks the woody portion of the vine.
The following links take you to some articles which should assist in your investigation:
The following article gives some general information on wisteria:
Hopefully these will be of some use to you.