Winter Project: Growing Wisteria from Seed
From the shape and size of these wisteria seeds, I’m guessing they’re from a mature Chinese - not Japanese - wisteria. Today they’re soaking in warm water. Tomorrow, they’ll be planted.
Back in September, a friend had questions about wisteria. Her mother has beautiful vines perched on a pergola at her house. The vines were producing what look like runner beans, and she was wondering if these pods were the plant’s seeds.
The pods you see hanging by the hundreds, sometimes thousands, from a mature or even juvenile wisteria are the plant’s seed pods: each pod contains from one up to six seeds. The pods develop during summer, mature in fall, and in large numbers, burst open in October. The seeds are dispersed, and given the right conditions, germinate.
So, my friend wants to grow wisteria from these seeds. Well, I got excited too, and asked her to wait until early winter, after the pods have dried and turned brown, to pick them and share a few with me. This morning, she brought me a bag of about a hundred pods.
Although I know as much about wisteria as a UConn certified master gardener should – which is to say a lot - this is my first try at germinating wisteria from seed. I know that the hard seed capsules must be soaked first in water, preferably spiked with a little hydrogen peroxide. I know that they take some time to germinate, but are fast growers once they get going. Wisteria needs at least 6 hours of sun a day. And if you’re really committed to doing it right, you must build or buy a large, sturdy pergola for the vines to weave their way through.
I also know that it will take up to 15 years for these seeds to become fully mature wisteria vines – the magnificent kind you see in the southern part of the U.S., in places like Savannah. The flowers hang like fairy lights on large tendrils, and depending on the variety of wisteria floribunda you have, are a combination of soft purple, white, violet, yellow, and/or pink.
The Japanese variety features more pink in the flower, and a lighter bark with spots of white. The Chinese variety is almost purely purple and white, with a darker bark. Based on the shape of the seeds my friend gave me, we have the seeds from a Chinese wisteria. But I asked her to bring me a summer photo of the flowering plant so I can confirm that. She has one and is going to send it my way.
I’ve placed about 20 of the seeds in a glass of warm water. They’ll soak until tomorrow, and then I’ll go with the plastic bag method of germination. I’m going to stratify another 20 or so seeds in the refrigerator until late spring, when I’ll plant them in pots outdoors. And I think I’ll take another 20 or so and nick the hard seed shell, then soak, and then plant in soil.
This will increase threefold my chance of successfully germinating the seeds. And although this is a long-term commitment, and I will likely never enjoy the vines in their glory, someone else will, and that’s good enough for me.
Live in peace.