Generally ALL wisteria is grafted, as seed grown wisteria can take years to ever produce flowers. But it is only other vining wisteria rootstock - often seedling - that named cultivars are grafted to, not any type of tree. A tree form wisteria is merely a regular grafted wisteria vine that has been trained over time into a single stemmed, tree-like shape. How tall the tree form (aka. a 'standard') will get depends on how long/how high it is trained vertically with any lower shoots or branches removed. As the plant ages, the 'trunk' will thicken and become self-supporting, eliminating the need for continued staking.

Since the wisteria is only grafted onto another wisteria rootstock, the growth is the same as if you were just growing a regular wisteria vine. This is a very aggressive vine with regards to shoots eminating from the root system, which on a mature vine can be very widespread, often shooting up yards away from the mother plant.

Thank you Gardengal, that explains what I've been reading about training the vine into a tree. =) I hadn't realized they are all grafted, though I did know seedlings can take many, many years to flower.

Would you recommend against either buying one or attempting to train one, then? Many accounts I have read have stated they are seemingly not all that difficult to control for a vigilant gardener. And there aren't that many places in our yard it could sprout that I wouldn't notice and nip. Neighbors' yards are pretty blocked off by physical barriers, though if the roots managed to travel that far then get under them I suppose it would be possible.

My two big concerns asking about root system are these:

a) I live in an area with a lot of steep hills and granite rock under soil that's not all that deep. The granite is exposed on a lot of the hills and most homes are on steep slopes, as is ours. Anything that requires a deep root system is probably not going to thrive in my yard.

b) The area I am thinking of planting has utility pipes in the vicinity, a few feet away. I want to make sure I don't get anything that would damage them. I have checked with town utilities and shallow rooting plants are fine in this area, we have Weigela, Inkberry and Hydrangea even closer and in one case directly over them at the moment, and an Arborvitae about 4 feet away. Would a Wisteria Tree be an inappropriate plant for this area?

Ditto everything gardengal said.... I don't know the answer re the utility pipes (but my Chinese wisteria has been growing above utilities for 10 years or so and there are no signs of problems... crossing my fingers.... :-)

I grow the Chinese one as more of a large shrub than a tree. It displays nicely that way when it flowers. The young Japanese one we're keeping to a more upright form to allow more space for the flowers (which are on longer racemes) to display nicely. I was hoping it would bloom last year but it didn't. Maybe this year....

You can see pictures of mine and read my maintenance notes about them at the link below. Wisteria are beautiful but a nightmare if not maintained. Think seriously whether you will maintain it diligently - and how long you plan to live there (the next owner may curse your name! :-)

Here is a link that might be useful: my garden's maintenance manual - wisteria

Training a vine into the tree form is very time consuming....what you see for sale in this form are plants that have a good number of years behind them. If this is what you are looking for, then I'd bite the bullet and purchase one already done.

The utility pipes should not be a problem as long as they are in good condition and you do not plant directly above them. And the vine can take some rough soil conditions as well - in fact, I think it blooms better if given tough love :-)

Hi, just thought I would pipe in here to say I just bought a wisteria tree from cottage farms. They sent me a stick on a stake. I put it in a container and it is just now starting to come to life. Ive read that keeping it in a container will allow more control. I think the website said it will grow up to 6 feet tall.