The first and most important thing that I learned from my studies with Boon was that the health and vigor of the tree were preeminent. Without a strong tree, all of the wonderful technique that I was learning was of no use, and maybe harmful to the tree. That was a fact that I soon proved true with a very nice Subalpine Fir. I still miss that tree, as I had collected it with my Grandfather, the person who started me in bonsai. It was so long ago that I can’t accurately recollect the tree’s health before I started. I certainly styled it aggressively, but with no visible cracks or tears. After flushing out with spring growth, it promptly turned brown and collapsed. That was well before Akadama, proper soil, and proper technique, and it was planted into a tall, moisture sucking cascade pot. Since then, I have been working to identify when trees are healthy and strong and able to respond positively to any bonsai technique I apply, whether it’s bending, pruning, decandling, repotting, or even just spraying.
A question that comes up frequently is whether to repot a sick tree to get it healthier. That is pretty much a resounding NO. Think of it this way. You are having some health challenges and the doctors tells you that if you drink more water, get a little more exercise, eat a little better and drop a few pounds you will be just fine. The other option is open-heart surgery, which may or may not be successful. Which would you prefer and what would make you healthier in the end? I personally would not be choosing to go under the knife. So before you repot, ask yourself if instead you can monitor water more closely? Maybe you should be checking morning and evening instead of once a day? Or maybe just paying closer attention each time you water. If it’s lacking moisture, maybe you soak it down twice each watering session to get better saturation. Or maybe it’s backing off until the next round.
I have been able to really make a difference by paying closer attention to each plant, even the same size species in the same size pot. It really does help. That said, we DO repot in order to build up the strength of an existing tree. That might include moving a tree from a collection container, or a nursery pot into a bonsai container. It may also include moving a tree up or down in pot size to move it along in its development. But the point is to only repot a reasonably healthy tree and giving it what it needs to be successful.
Another factor in the equation is sunlight. I was in Ashland with the Southern Oregon group awhile back and a gentleman had a very large and wonderful Black Pine. I told him that it could use more sun and he admitted that his yard was mostly shade. Some folks interpreted that to mean that I was saying it was unhealthy. It was not. It was just the right shade of green, and had good buds. But the needles were longish, and more importantly the internodes were very long.
More sun will actually allow the tree to gather it’s needed resources in a smaller area, which translates to shorter needle and internode length. That also means that the quality of the solar energy the tree is collecting is much higher, enabling it to build the necessary energy to back bud and build a more compact tree. So just getting your tree more sunlight can really boost it’s energy. The problem can be that you just get way too much sun come July and August, and then it’s time to break out the shade cloth. But the trees will thank you with lush, verdant growth.
The single biggest indicator of tree health coming out of winter dormancy is the size of the new buds. Relative size indicates how much energy the tree has built up. You may have dense foliage, but if the buds are small, the tree is weak. It may have been that the tree put on some great growth the last couple of years, but at the end of last season it ran into troubles. Maybe it got to dry during the summer and weakened the roots, or not enough fertilizer, or it got shaded out. Something happened to stress it out. On the other hand, a tree might have had a rather weak showing in spring, but built up strength in its sparse foliage because the watering, fertilizing, and sun light you gave it were spot on. So, what exactly would that look like?
The clearest examples are the buds of a Japanese Black Pine. On an untrained or nursery stock tree it’s very easy to compare the branch tips. At the apex they will be a creamy white, with a nice stiff point. There will likely be a very large bud surrounded by many smaller, but equally white buds. Down towards the bottom of the tree, or on the interior, where the buds are likely weaker, they will be a darker color, maybe reddish, with a rounded tip, and much smaller size. There is also likely just a single bud. The difference is very dramatic.
Black pine apex buds
Black pine lower side bud
That differing bud strength is what we are trying to balance with our pruning and decandling techniques. So pines are really obvious, but many species are not. There are some species that I grow where I cannot see any buds or tell if the branch is alive until they start growing in the spring. That makes things very challenging, but each year my eye gets trained a bit sharper.
On deciduous trees, you will likely see large, fat buds on the tips and upper portion of the bonsai, but as you work in towards the interior, they start to weaken. You may see internode sites where a microscopic dormant bud exists, but there is no sign of them, and nothing to activate them. Take a look at the fatness of the branches. Shoots which have grown thick and coarse will have many more and larger buds than the thinner and weaker branches. This means that most of the trees strength will be concentrated in those thicker shoots. That may help us if we are trying to thicken the trunk or a certain branch. If not, it really serves to weaken the other branches if not addressed.
The good news is that those strong shoots indicate that the overall health of the tree is strong. By pruning these strong branches back to one node for opposite branching species, like maples (two buds, one on each side), or two buds for alternating species (most of the other deciduous trees) we can control and even out the branch strength. Leave the weaker branches longer and with more buds. I rarely, if ever, regret cutting out those coarser sections of branches.
For conifers, foliage is another great indication of health. Remember that you want to look at the total needle mass. That means that roughly ten needles that are 2” long have the same strength and solar capacity as twenty, 1” needles. Make sense? For trees in development, you may have areas that you decandled or otherwise pruned and end up with needles of varying length for the short term. Feel the needles. Are they crisp and cool? That’s a great indication of health, as well as their color. A deeper color relative to the species is stronger. Anything straying towards a yellow or pale color is weaker.
Strong trees are also occupying the entire pot with roots. This is a great indicator of strength. The denser the root system, the more gas in the tank the tree has for styling work. During this time of repotting, it’s a great time to examine the strength of the root system and make any corrections needed. One of the best indicators of root strength is the amount of water taken up by the tree. During the growing season, if the tree is utilizing all the water you give it at any one time, the tree is in balance and chugging right along.
Here’s to a great growing year ahead! Scott Elser