I posted this photo last December of a Sweetgum (Liquidambar styraciflua) I had been growing in the ground for a few years. The tree started out as something just beyond a seedling, in a nursery pot. I was developing it in the pot, using directional pruning techniques to create taper and movement. But the tree just wasn’t fattening up as I wanted it to. So I put it in the ground, knowing that the fastest way to make a smaller tree into a bigger tree was to give it room to grow.
This photo shows one classic way to get thickening in the base of your tree: letting a low shoot run. And boy, did this one run! In the process, I now have a 3″ trunk base whereas I started with a 1″ base just a few years ago.
And so, on May 1st I sawed this tree out of the ground. Here it is with its root mass and soil ball (I shook off what I could). It’s grown like a weed, as you can see.
First I gave the root mass a good washing off. I don’t want any native soil, as it’s not needed. The tree will go into a fast-draining coarse bonsai soil, which will promote regrowth.
I also cut back the long leaders; they aren’t necessary at this point.
Take special note of the branch growing from beneath the large cut. This is important to ensure I don’t get any dieback into the root from this area. I was careful to leave the branch collar when I chopped the big leader, also for this purpose. But this branch is my insurance policy. I’ll leave it for a year or so (though I will keep it cut back while developing the structure of this tree).
The next step. All of the foliage is gone now. This is absolutely vital when collecting deciduous trees that are in leaf. If you fail to do this, the tree continues transpiring moisture through the leaves and will literally dry out.
I’ve also cut back the roots in the first stage. You can see one of the coiling roots that will need to go.
You can also see the trunk line of this specimen and the massive taper from the base. The trunk measures 3″ across above the root zone – so I’d say my ground-growing effort succeeded.
Now I’ve got the root zone cut down to size. Notice how much smaller it is in this photo than in the previous one. It’s a common mistake to leave too many and too long roots on a collected tree. Remember two principles when working on the root zone of a newly collected tree: 1) the roots need to be cut back enough so that they will fit in a bonsai pot in the future, including cutting them shallow enough for that same purpose; and 2) they need to be 2-3 diameters long so you can build taper in them when smaller roots sprout from the cut ends.
What’s the best front for this tree? I have at least a couple of options, and I don’t have to choose now.
Should the trunk be chopped back farther? I can see a likely spot for a chop. But again, I have options and don’t have to choose now.
After a good dusting with rooting powder, here’s the tree all potted up. All cuts 1/4″ and over were sealed with cut seal. This has to be done every time you collect a tree.
And a third possible front. I’m thinking this is my favorite.
Sweetgums are great to work with. They grow fast and will regrow from chops very well. It does take some time to build ramification and get some leaf size reduction. But all in all, they are one of my very favorites.
Today this tree is showing signs of pushing new buds, so it looks like the harvest was successful.