Do Mugo Pine Need to Be Pruned?
There are two main reasons for pruning mugo pine: to limit the tree’s size and to shape the tree. If you do not want to do either of these things, there is no need to prune your mugo pine. Mugo pine is a small, pyramidal shrub that can grow between 4 and 10 feet (1-3 m.) tall. If yours looks like it will be on the taller side and you want it shorter, you’ll need to prune it to keep it small.
How to Prune a Mugo Pine
The principal rule when it comes to mugo pine pruning is this: do not prune in the fall. Pines do not produce new buds from old growth. That means that the tree will stop growing from any pruning points if you cut branches out of season. Instead, prune mugo pine in spring and only trim the new growth. Tender new growth on mugo pines appears as “candles” on the branch tips. To keep the mugo pine from getting too tall, cut the mugo pine candles in half in springtime. This reduces the size of the new growth that will achieve in the season. Done annually, this keeps the mugo pine to a reasonable size. It also makes the shrub/tree’s canopy thicker. If it gets too thick, you may want to remove some exterior candles.
Pruning Mugo Pine to Shape
The ideal shape for mugo pine is smooth and rounded. If your mugo pine had holes in its canopy, you can correct them by shape pruning. Pruning mugo pines to shape involves not pruning candles in areas where more growth is required. Figure out which candles can grow to fill in a canopy hole, then skip these when you are pruning.