Black pines are one of a number of species that don’t naturally produce balanced growth. These pines are likely to produce strong shoots near the apex or at the ends of lower branches and weaker shoots everywhere else.
Of the many ways to balance this growth, the most effective I know of is to decandle the spring growth at different times. I start by decandling the weakest shoots, wait one or more weeks, and then decandle the strongest shoots.
If the tree has small, medium, and strong shoots, I might decandle on three different days ten days apart. If the tree has small and strong (but no medium) shoots, I might decandle on two different days two or three weeks apart.
The basic idea is that you give the weak shoots more time to produce summer growth and you give the strong shoots less time to produce summer growth (see “Decandling, an in-depth guide” for details).
I typically only do this on a handful of trees each year, and some years I don’t do it at all. If, however, I see the need and I have the opportunity, I give it a go. Here’s how this works in practice.
The black pine below has a number of really strong shoots, but the rest of the shoots are relatively weak – a perfect candidate for the multi-day approach.
Black pine with unbalanced growth
I start the decandling process by removing the smallest shoots.
After decandling the small shoots
It’s hard to see the difference between before and after this work as the small shoots in this case were much smaller than the strongest. Here’s a close-up.
Close-up showing decandled shoots and remaining strong shoots
About a week and a half later, I removed the strongest shoots and plucked some needles. I kept three pairs per shoot at the top of the tree, four pairs per shoot in the middle, and five pairs each on the lowest branches.
After decandling and pulling needles – 17″
I haven’t shared an update about this tree in a while as I’ve been rebuilding the apex for the last few years (see “Black pine – work in progress“). Now that the new branches have begun to fill in, I plan to wire the tree and refine the silhouette the next time I work on it.