Training a shrub into a small tree

I have a couple 15-gal Vitex agnus-castus and one 15 gal Chilopsis linearis which were just planted, and I would like for them to become small trees eventually instead of shrubs (they all have very shrubby forms right now). Any tips on when I can start to prune out lower branches to help encourage them to be more tree-like? Should I leave them shrubby for a few years while they establish, or can I start training them now? Thanks for any advice!

I have pruned my Vitex all times of the year. Even if you prune the lower portion of it now, chances are you'll have to again by summer. They're pretty tough once established.

Mine's not established yet--that was why I wasn't sure if it was OK to do any significant pruning on it yet. It's dormant right now so this would generally be the time of year that I would prune it, but since it was just planted a few weeks ago I wasn't sure if it would be better to leave it alone for a year to let the roots get established, then start pruning it.

I mowed my Vitex down with the lawnmower for two years in a row before I realized what it was. They sucker like crazy so they are somewhat stubborn to train into a tree. I wanted mine to have three trunks but I think it ended up with about six of them. Personally, I can get a better idea of how I want it to look when it is leafed out. When they are dormant they just look like a bunch of sticks and it's hard to tell which ones to cut.

I would let the Vitex grow this year, but like e-guy says, it seems one can prune them anytime. They grow like crazy here, and our city horticulturist is using them as primary trees on city property. They present quite a show in August down here. They take the city traffic pollution very well. I like the multi-trunk look, and I think it may prove to be a challenge to limit it to a single trunk. They are also very easy to propagate.

These two are new to me, and the chilopsis is out of my range, but I read that both bloom on new wood. Plants seem hardier to me when they're left to do their own thing for a year in the ground before trimming. That also helps you to see what direction the plant you've got wants to grow in. I have read that is the way to train butterfly bushes into standards for example. So that is what I would do, only cutting out dead or damaged branches for the first year, and then shaping it as it fills in, the following summer.

It's strange that you should mention butterfly bushes, because when Vitex are young, they are commonly , mistakenly identified as butterfly bushes. They flourish in our area.

You could probably get some good info on the Chilopsis in the southwest forum.

Yes peony, I also read that they are sometimes mistaken at first glance to be marijuana plants! Due to their foliage.

PG5, You are correct, and much more courageous than I ('course I live in Alabama) in bringing it up!!!:))

ecrane3. Did you see the Jeff Beck's photo in the plantfiles. Now that is a vitex tree! I had my doubts about your project, but I think I will plant another vitex shrub this spring and have a whack at it. They do very well on Nantucket. They give us good Aug. color. Vitex, Chaste Tree, Lilac Chaste Tree, Monk's Pepp PF Pictures 6 490 2006-12-22 18:40:17 Jeff Beck Patti

This message was edited Jan 3, 2007 1:32 PM

I have my doubts about the project sometimes too--the Chilopsis I'm pretty confident I can train into a tree because most of the ones I've seen are that way, but most often I've seen Vitex as a shrub, although there are a few exceptions. I like the Vitex no matter how it ends up, being a tree would be a little better from the landscape design perspective because as a shrub it'll eventually crowd out the things planted around it, but I don't care that much either way. Sounds like the consensus is I should let them settle in a bit first before I prune, so I think I'll leave them all alone this year and then prune them next fall/winter. And if the Vitex fights and wants to be a shrub, I'll let it do what it wants!

I would like to try the same thing with a purple leaf sand cherry (they're very common here). I think it's probably best to wait a year, but not too long. How are you going to go about it?

I was just going to start removing the lower branches at the base and see what happens--probably just do a few the first time to make sure it doesn't trigger a massive attack of suckers, and if those branches go quietly I'll do a few more, then as it gets taller I'll just keep removing the lowest branches until everything's where I want it. I figure it'll take several years to get it looking anywhere close to how I want. Not sure if that's the best way, maybe someone who's done this before will have some good tips!

Ecrane, I think that's the best approach.

Sounds like a plan! I'm with you, ecrane, if it doesn't work, I'll have a nice shrub.

ecrane, I don't know how commonly available vitex is in your area but it would be helpful if you could choose one that has not already been topped or is less shrubby to start off. That's what I did. Mine had one trunk that branched out at a decent height when I bought it as a gallon plant. It's grown considerably and it getting very tree-like now with no suckering. Since I like it's shape I haven't pruned it much. Most of the plants I see in gallons are already shrubby in form but it is possible to find one with a single strong leader.

They are very commonly available here, but I already have the plants--the landscapers ordered them and planted them so it's too late to pick my own! They are all pretty shrubby looking now, but have a couple of main branches, so I may not be able to get all the way down to 1 trunk but I think I have a pretty good shot at 2-3 trunks as long as they don't sucker like crazy from the base.

Oh that is excellent advice! Thanks. I meant as far as picking one with a strong central leader to start with. ecrane, isn't vitex multiple trunked anyways? That is what I saw when I googled it.

http://horticulture.missouri.edu/starbuck/list9/vit_neg.htm

This message was edited Jan 3, 2007 8:53 PM

Here's a photo I found of a Chilopsis tree.

http://images.google.com/imgres?imgurl=http://www.desert-tropicals.com/Plants/Bignoniaceae/Chilopsis_linearis.jpg&imgrefurl=http://www.desert-tropicals.com/Plants/Bignoniaceae/Chilopsis_linearis.html&h=267&w=200&sz=18&hl=en&start=9&tbnid=ZClo8f_4Tyu_CM:&tbnh=113&tbnw=85&prev=/images%3Fq%3Dchilopsis%26svnum%3D10%26hl%3Den%26lr%3D%26sa%3DN

I've got plenty of Vitex seeds. If anyone wants some just let me know.