The commercial methods of Wisteria propagation can be adapted for the home gardener who just wants to make a few extra plants.
i) Seed
Wisteria seeds (either picked or purchased) will germinate and grow easily. The best time is probably March or April, the seed can be soaked for about 24 hours in a jar of water. It can then be sown in a pot or flat of any good seedling compost and left to germinate in a greenhouse, cold frame or windowsill. After germination the seedlings can be transplanted into their own pots and grown on like any other plant for the rest of the year.
Remember Seed picked from a named flowering Wisteria cultivar will NOT produce seedlings with the same characteristics. They will vary in how long they will take to flower and in the quality of the flowers. They will be subject to all the disadvantages of Wisteria seedlings outlined elsewhere in this FAQ.
ii) Root Cuttings & Suckers.
If your plant already has suckers growing around it, these can be dug up and planted separately. Alternatively if the plant is large but has no suckers some of the root can be dug up, removed from the plant and planted separately. The root piece removed s hould be at least a foot long with a caliper of half an inch or more. It should be replanted so that the top of the removed root is just below the soil surface. It will generate new buds and send up a new Wisteria shoot.
Remember root cuttings and suckers will produce new plants that are the same as the original plants roots. If the original plant was a seedling or a rooted cutting the new plants will be the same. However if the original plant was grafted the new root cut tings will not be the same as the original plant.
iii) Layering
Perhaps the easiest if not the quickest method for the home gardener who wants a new plant that is sure to be the same as the original. A long one year shoot that can be pulled down to soil level is needed. A portion of the shoot is buried in the soil, bu t with the shoot tip still above the soil line. The part of the shoot that is buried can be wounded with a sharp knife, (a slice of bark is removed). After a year the shoot can be cut away from the main plant as the part that was buried should have made i ts own roots. This can then be transplanted to a new location.
iv) Softwood Cuttings
Some Wisterias root easily from softwood cuttings others do not. This method will work with some cultivars and not with others. Cuttings should be made from the new years wood in June, July or August. The cuttings should be about 6" long with one or two leaves, they should be nodal (the base of the cutting should be just below a leaf node.) They should be dipped in a rooting hormone with an IBA concentration of 0.5% to 0.8%. The cuttings should be stuck in a pot or flat of any good cutting compost. A clear plastic bag should then be put over the pot or flat and sealed. The whole thing can be left on a windowsill or greenhouse out of direct sunlight, if rooting is going to tak e place it will probably start within 4 to 6 weeks. It is important that the cuttings are sealed inside the poly bag to keep the humidity up and prevent them from drying out.
