When collecting deciduous trees, we usually end up with nothing but a trunk. Well, so it seems. For most species, nothing could be further from the truth. You see, one of the fascinating things about the growth of woody plants is that they produce buds, from which come shoots that become branches that in turn produce their own shoots that become branches. There are a few types of buds, namely terminal, axillary and adventitious. For the collected deciduous tree, the axillary and adventitious buds are absolutely vital to recovery and ultimately the creation of a bonsai.
Here’s one of this year’s collected hornbeams. The trunk base is 3″ and it’s almost 16″ to the chop. I can easily see a very nice bonsai in this specimen. But there’s only a trunk and buried, chopped roots. Can we really expect a whole tree to emerge from this beginning, and if so how?
That’s where the humble bud comes in.
Though they’re barely visible to the naked eye, this trunk features dormant buds just waiting for a hormonal signal to emerge. In this case the bud is properly termed adventitious, though it actually appears at a spot where the original seedling had a single leaf. In its first manifestation, this bud was an axillary bud because it appeared in a leaf axil. As the tree grew, that leaf fell away and the shoot that emerged grew in length and thickness. But there remained at that spot the hormonal potential for new bud formation. And in many such cases, you can actually find on a mature tree these tiny buds lying dormant.
Is it a sure bet this bud will emerge and do its thing come spring? Assuming the tree is going to survive, yes, it’s virtually a certainty. This is one of the ways that woody plants ensure their survival. You’ve probably seen many examples of trees that have been pruned – or pollarded like crape myrtles. The adventitious buds reliably activate so the tree is able to recover and continue to survive.
Here’s a second example, the American elm I harvested earlier this year. As with the hornbeam above, all I’ve got is a trunk. In order to end up with a bonsai – a representation of a complete tree – I’ve got to rely on adventitious buds.
Here’s one of the numerous buds already emerging on this American elm. What’s really exciting about this one is its location. Can you picture the new apex of this tree developing from this bud? I sure can. Not only that, it’s on the right side of the trunk to continue the subtle movement that will make this a really nice specimen.
Every rule has an exception. Bald cypress does not feature obvious dormant buds. Rather, its dormant buds lie beneath the bark – so-called epicormic buds. This doesn’t make bald cypress any harder to collect than other species; you just don’t have any idea where the new shoots will emerge. Of course, bald cypresses tend to produce so many buds you don’t really miss the ability to see where they are.
Here are two buds that have broken through the bark. The top one is barely visible – you pretty much need a magnifying glass to see it. The bottom one is nice and green, and with a few warm days will continue swelling until it begins to extend from the trunk.