Whist-eria

Guest post by Carmen Leskoviansky 

My second visit to Crataegus Bonsai was in the spring of 2018 for the spring Seasonal. It was a glorious day in late May, and after some tea and rousing conversation around the dining table, I headed outside with my compatriots to get to work. 

Sitting in the studio, perfectly centered in a beam of sunlight shining down from the heavens (skylights) was a wisteria late in bloom. Its tendrils were reaching out to us, beckoning us to come take a closer look while its flowers perfumed the air and its leaves rustled softly in the spring breeze. There was much exclaiming of “ooh” and “ahh”. Michael followed us out to the yard a short time later and gave us our first directive – cut off all the flowers. Then, defoliate it.

Chinese “Whist-eria” in 2018 during Carmen’s second Seasonal

Such is the nature of bonsai – ephemeral and constantly changing. And, this nature is one of the many reasons I love bonsai so dearly. If you don’t pay attention, you’ll miss it. “It” being everything and anything from the extension of root tips, to the unfolding of leaves, to the bloom of a flower. One must be present and engaged at all times with nature and the nature of change which I find both soothing and, well, engaging. 

Yet, beyond the philosophical reasons for removing flowers from and defoliating wisteria, there is a practicality to it. It takes a whole lot of energy for a plant to create fruit. This energy could be spent elsewhere on new branches, new leaves etc. Removing the flowers, thus preventing a tree from fruiting, reroutes the energy to leaves and branches.

Additionally, the ramification of wisteria comes from buds that form at the base of the flower stalks. Wisteria has two kinds of growth – tendrils and branching which comes from buds at the base of the flower stalk. The tendrils, if left to their own devices, will climb anything and everything they touch. The more delicate branching, what we want for refined bonsai, is much more elusive. Cutting back to the leaves/buds at the base of the flower stalk will create the branching that leads to refinement. To further refine a strong wisteria it can be defoliated by cutting each compound leaf back to two leaflets after flowering. The wisteria will then re-flush with new shoots, leaves, and, with any luck, a few more flowers. 

Same Wisteria in 2024

I spent a couple of summers during college working at a high-end retail plant nursery, and I was often faced with the question from frustrated gardeners “How can I get my wisteria to bloom?!” I would start by asking all of the initial questions, “Does it get enough sun? Have you pruned it recently? When did you prune it? Have you been fertilizing?” If none of those answers seemed to clarify the problem, I would switch to the more advanced questions, “Have you tried hitting it with a baseball bat? Running over it with your lawn mower?”

In all seriousness, wisteria can be rather temperamental when it comes to flowering whether in the ground or as a bonsai. The best bloom I have seen so far has come a year after the bonsai almost died and then spent a summer growing wildly to recover. A second wisteria in the yard has been weaker this year than in the past, so I look forward to seeing if the trend continues with a bumper bloom next spring. If that’s the case, perhaps taking a baseball bat to the wisteria isn’t as ridiculous an idea as it seems. 

Yet, it’s unlikely that a near death experience caused the excessive flowering, but rather the opportunity to grow unrestrained for a season. So, try full sun in the spring with part shade in the hottest parts of the summer and plenty of water and fertilizer. Protect your wisteria from severe cold, preferably in a greenhouse or cold frame, but if you have mild winters, sitting on the ground should suffice. If all else fails, throwing it from the roof is always an option.