Looking at older pictures, I’ve started to notice how much this tree has been swelling at the base (left side), mainly due to sucker shoots which I constantly remove during the growing season. I don’t think there’s much I can do about it, so hopefully it doesn’t become too grotesque.
Yew are pinched in the spring to balance the energy of the tree. If they are not pinched, the outer growth will become coarse and the inner growth weaker. Pinching helps maintain or develop finer branching. Yews are not pinched to promote backbudding – they don’t need any encouragement to do that (if anything, they produce too many buds).
Whole-tree pinching as shown here should not be done on trees in development! It is counterproductive to weaken the tree when you are trying to build a foliage mass and grow out branches. I’ve been developing this tree from nursery stock since 2006 and this is the first time I have pinched the whole tree.The last six or so years have been spent developing the roots and basic branch structure.
This is also the first year in which I have held back on heavy spring fertilization – I just gave a little bit of mild organic (chicken manure) to help it bounce back from the pinching. I am not planning on fertilizing it again until late summer/early fall, once everything has hardened off. Too much fertilizer will make the second flush too vigorous. Bud selection and wiring will also happen in late summer/fall.
This tree does still need some branch development, but nothing major. It is often helpful to look at a tree from above to see design weaknesses. Most trees should have a pretty rounded crown when viewed from above. This tree has some noticeable gaps, but they should fill in pretty soon.
This little thuja was put into a nice Shibakatsu pot last week. This is one of my favorite pots and it suits the tree better than I expected. The major work on this tree is now done – both above and below ground. Now it is just a matter of pruning and pinching to develop the foliage pads. As I refine the foliage, I will slowly scrape the dead bark of the old top jin while trying to maintain the detail of the deadwood. This will be a slow process.
In keeping with the larch posts, I thought I would talk about what is perhaps the most infamous pest of Larix laricina – borers. Borers are insect larvae that chew on the living tissue of trees as they tunnel around inside the trunks and branches, invisible to the naked eye. The parent insect (usually beetles or moths) lay their eggs inconspicuously on the bark of the tree and, upon hatching, the little demon-spawn chews its way in.
One interesting thing about borers is they are usually only a problem on weaker trees with a subdued systemic defense. Strong trees with a heavy sap flow are better able to restrain a potentially disastrous borer infestation. What does this mean for bonsai growers? Borers are most likely to gain the upper hand on recently collected trees, or very mature and slow-growing bonsai. In other words, borers pick on the weak and the elderly, making them complete assholes. This source says that “the chewing of some [borer] species may be heard by someone standing near the tree”. Ok now that is just scary.
Most often, a borer infestation is not identified until the damage is done. Just one enterprising borer could potentially girdle a trunk or a branch, causing the sudden death of a huge part of your tree.
Nick Lenz is a veteran of the borer wars, and describes in detail his approach to dealing with them in his book Bonsai from the Wild (2nd Ed.). If you live in the North East and grow any native species, especially larch or cedar, you need this book! Essentially, Nick’s approach is to bag and fumigate every larch he collects, assuming it is infested with borers. I have not been this aggressive with my collected larches (yet), although I have been treating them proactively with a systemic insecticide (imidacloprid). Hopefully I don’t regret my complacent approach in the future…
What Nick does not talk about in his book is perhaps the most alarming cases of borer damage – that on mature and established bonsai. My friend and bonsai mentor has experienced this problem this spring in a big way. Here are some pictures of what you hope to never see on your larches.
Fortunately these trees have not yet shown any signs of branch dieback due to the borer damage, although the scars alone are rage-inducing. He treated the infected trees according to Nick Lenz’s prescription outlined in his book.
While I have not personally seen borer damage on my larches, my friend’s experience here has definitely raised my level of vigilance and hopefully yours as well.