While I love using collected trees for bonsai more than any other source, I also grow trees from cuttings and seeds. There’s really nothing at all wrong with bonsai grown from cuttings and seeds. After all, our goal is to create the impression of a larger and older tree in a small package, and this can certainly be done using material from any source.
I began growing material for bonsai in the ground some years ago. Ground growing results in quicker thickening of the trunks of your young trees, which of course helps them look larger and older. With the exception of the tiniest bonsai, the mame and shohin sizes, it’s really best to start with a basal trunk thickness of one inch or more. Growing small trees in the ground for just a few years can get you the thicker trunks you need. All it takes is a little guidance as the material grows out.
Here’s a good example of what you can achieve in just a few years. This is either a willow oak, Quercus phellos, or a water oak, Quercus nigra. It seems to have leaves of both species. Regardless, it grew as a volunteer in an old garden area I used years ago for vegetables. Isn’t the twin trunk awesome looking! With a trunk base of 1.75″, this tree could be lifted as early as next year.
I’ve had this blackgum, Nyssa sylvatica, in the ground for two years now. The trunk base is 1″ in diameter, and it has nice taper into a trunk line I’ll cut to next season. I plan to leave it in the ground for a while longer, as I’d like to fatten up the trunk some more before lifting it.
Next is a sweetgum, Liquidambar styraciflua. I had this tree in a nursery container up until two years ago, then decided to put it in the ground to thicken it up. I’ve cut it back a couple of times, then let it grow out wild. The trunk base is now 2″ in diameter. You can see I also have a secondary trunk growing out near the base, which I can let continue growing to further thicken the trunk. What I need to do while this is going on is to manage what will ultimately be my desired trunk line. So I’ll do some judicious pruning in 2016.
Last but not least is this Chinese elm, Ulmus parvifolia. I grew it from a cutting made a couple of years ago, and planted it out this year. The trunk base is just under 1″, and this has been largely achieved by leaving alone the long and thick main trunk you can see taking off to the right. I’ll remove this leader next spring, while allowing the one lower down the trunk on the left remain and grow untrimmed. This one can then be removed in another year or two, at which time I’ll have both a thick trunk along with very good taper. Then the tree can be lifted and grown from a bare trunk.
Thanks for the replies.
When, if, time permits, can you document and share the Sweetgum 2016 pruning? Some of the pruning you do may reflect what we’ve been discussing….or provide new insights to techniques.
Thanks for the suggestion, John. I’ll try to capture some pruning of in-ground material in 2016 to show some details of how it’s done and why.
Answer number 4. To clarify my large grow box. The size I usually use in 12″ x 16″ x 5″. Cedar wood. Is that an okay tactic?
That should work fine. The extra depth should be a big help.
I’m not sure how you can explain answers to my questions. Perhaps visuals with red lines would help. Ground growing does indeed increase the trunk….and every other branch as well in the process. This also creates very large scars that need time to heal or cover over. When you talk about that next hard cut…the trunk being ready…I have these first questions:
Is the trunk at the diameter you wish or less than thickened fully?
Do you continue ground growing after the hard cuts to accelerate wound heal over?
When you hard cut to that trunk, do you cut those thick branches flush to the trunk(slight indentation)?
Do you leave branch stumps…such as cutting like 1/2″ away from the trunk?
Do you plant this new trunk in a larger trying box? If yes…..For how long?
If you dig up the trunk you lose roots….does this root removal hinder cut healing or further growth if the trunk is not at the desired thickness?
Most of my trees are in the ground growing. About two or three are nearly ready for digging. Trunks are about 3.25″ diameter now. Others, slower at growth, are 2.25″ to 2.5″. The hard cuts would bring the trees down to about 18″ to 20″. There are scars to finish healing over. The trees ready are American Elm and Hachberry (Celtis Sinensis).
Perhaps what I’m asking for is a continuation of the article over the winter months with next-step thoughts and visuals. If it’s possible.
Let’s see if I can answer these questions in order:
1. When I mention the next hard cut, this is done with the tree in the ground with the intention of leaving it in the ground for the next round of growth. The grow and chop process can continue for some time; it all depends on how thick you want the trunk to be and how many turns you want. The limitation is, more or less, patience.
2. The wounds heals over faster with the tree in the ground. When it comes time to lift the tree, the wounds you have will take longer to heal with the tree in a pot.
3. It’s best to cut the branch just outside the branch collar, to ensure you don’t get dieback. Once you get past the initial healing phase you can carve the wound back to make it more flush.
4. Once the tree is lifted, it usually goes into a regular nursery pot for growing branches (deciduous trees) or developing branches (evergreen conifers). I don’t generally go from the ground to a large grow box; I don’t see much point in that, as it isn’t needed for branch development.
5. When you lift the tree you lose all those far-flung fibrous roots. These regrow in the confines of the pot. Wound healing and trunk thickening slow.
I’ll post follow-ups as I can to illustrate the process of ground growing for trunk thickening and development.
Thanks for a quick reply Zach. Excellent thorough answers.
Answer number 3. That’s great to know! It does make sense. I can visualize the cut leaving the collar. I think that’s been one of my problems over time….thinking that I had to cut deeper and carve it out always. I have had die back with the deeper cut creating difficulty, an a long time, in healing over. Sometimes I’ve had to go and cut again deeper because of that die back zone. What I see as problematic though is that left over bump created by the collar and extra branch material. How can I tell the initial healing when the branch stump is still there?
Maybe one of your follow-ups on this post might sneak in a visual of that technique.
You’ll be able to see the initial healing after branch removal because the callus tissue will start rolling over. You can tell there won’t be dieback below the cut by the tissue rolling over at the bottom of the cut (the critical area). In time you can come back and carve any unsightly bump, because the sap pathways from roots upward and crown downward will have routed around the cut. But you have to be patient before performing this operation.