I'm not sure I understand your question. Are you asking if pruning will help develop your whip into a multi-trunked specimen? If so, no. Multi-trunked trees are not manipulated into that form, they come by it naturally. Or, you can plant multiple whips in adjacent planting holes to create the appearance of multiple trunks. Similar planting of multiple seedlings/whips in a single container or planting hole is a relatively common nursery practice, as in the "clump" river birches, etc. Some species are more suited to this practice than others.

But if your little tree at 30+" hasn't already developed multiple trunks, it's never going to.

Agreed. But, that doesn't mean the tree will not create some sidebranching lower on the trunk. The only disparity being that they will look like branches when the do grow and not trunks. There will always be a caliper difference between the two. If the appearance of multiple trunks was important to you, you should have asked for a tree with that form when acquiring it. Now, consider that the caliper of your one trunk will grow faster in diameter than if it competed with multiple trunks and the effect or appearance of older bark will appear sooner. Not such a bad deal.

Gardengal does have a point about clumping multiple specimens together, but at the price these things go for, it would hardly seem economical. If you could afford it thought, a small stand would be aweseome or maybe you could combine other colored bark specimins in close proximity, say Winter Lightening, Phoenix, Silver Vein, White Tigress. Just to name a few.

I would wait to see how the tree progresses this year and if you want a shrub, keep the top growth pruned back and hopefully you get some lower branching. Once you get some side branches you can prune the leader back some more, but I would not do that yet.

MJH

I had a paperbark maple that I wanted multiple stems on also. It was a seedling about 2' high. I fertilized it with a liquid fertilizer weekly in the spring and then pinched the top out. It did develope into 2 nice trunks. There was an indepth discussion on this forum a couple of months ago on this subject. You might do a search on this forum under paperbark maples(griseum) and see if you can find it. It might work for your maple variety as well.

Something you can try: If it's prone to suckering, it can be manipulated into putting out more stems if you put moist soil or mulch over the root flare. This is the crown of the tree. You can recognize it by the stripe it produces. This stripe seperates the roots from the trunk. Now, I don't know if your plant is prone to suckering. I looked it up in Michael Dirr's Manual but all he said was A. tegmentosum and those in its family are small trees or large shrubs. Sometimes large shrub means multitrunk. Sometimes it means branching near the soil line. So, anyway, you can try to cover up a bit of the lower trunk and see if adventitious buds form.

Hi all, thanks for all the thoughtful comments! I should have been more clear when I posted my question-- low branching habit would be just as good for me. I have now a specimen of A. tegmentosum 'Joe Witt' and one of A. pensylanicum 'BAN select' (from the wonderful Broken Arrow Nursery in Connetcticut--- (they also offer a specimen called 'Erythrocladum' in which the bark has white stripes on a greenish backround which turns red in the winter-- that's next for me!). I will try griseum's suggestion on one of them and see what happens! Both were topped previous to their purchase.

While we're on the topic, what about the phylogenetic relationship between tegmentosum and pensylvanicum? Some say they're identical, some say not...

Thanks again, Hobbes

You all have good taste . I dig them all and have them all . Everyone has good points . I got my original 'Joe Witt' from Heronswood . It is around 40" and still in a pot after 3 years . I am now in the mood to start planting more . If you want it to have more of a multi stem appearance try leaning it to one side to encourage newer growth to come from down low .That might work , but that is not its nature to be multi stem . I never really see them that much , because most people don't even know what it is . I have two 6' tall A. penn. 'Erythrocladum' and they are gorgeous . The striations are better than A. c. 'Phoenix' , but 'Phoenix' is just brilliant . The one to get is 'Bump' by far more white than anything out there. It makes 'Joe Witt' look tan . No one ever has any for sale . I have two 6-7' that will make you drool . 'Silver Vein' is a clean purple . Most growers are taking as much scion wood as possible due to the demand and difficulty . I hear A. penn. 'Erythrocladum'is about as easy as trying to put a diaper on a wolverine . Wedge grafts tend to look better as long as they are not side wedge grafts . I see growers putting two scions on one rootstock . To answer your question , I would plant more than one like MJH said . That would be cool to have two different colors . Acer negundo 'Winter Lightning' looks so dang good right now , especially with low afternoon sun . The original tree was spotted on I-24 near Chattanooga some years ago by Pat McCracken . He actually tried several times to get it going . Then finally during a rain storm , his umbrella got hit by lightning , hence the name . Cool! I would say close but I don't have a machine that measures DNA .thanks