Mugo pines in front of a rock face

The Mugo is one of Calgary’s star players. Attractive year round, they can be a strong feature plant or blend into the background, depending on planting site. Native of mountainous Switzerland, there are several kinds of Mugos. Most of us, when we buy one, are thinking of a variety called compacta, which is the popular tight, slow growing classic.

Unfortunately, not all Mugos are the same and, although they may seem to be at a glance, their growth patterns are different. The only way to know for sure what you are getting is through close inspection of the plant. Choose a branch at random and find the bud at the tip. Starting at the bud, scan down the branch until you find a break, by which I mean a physical change in the bark surface. We are looking for the bud scar, a ring around the branch in the bark. As each years growth expands out from its bud, a little scar or ring is left behind, staying in place to mark each yearly increment.

The distance between the bud and the first bud scar back is one year’s growth. Note the length of the shoot’s one year of growth. Keep looking down that branch and find the increment that is two years old, and then the third. How do their lengths compare? Choose another random branch on the other side and inspect it. When you have compared several shoots from different areas of the plant, you will have an accurate ruler to judge how much this plant grows each year.

This sounds a little tedious but, with a wee bit of practice, you will just see it. Annual growth increment inspection is also very useful in determining overall plant health. If a plant whose regular pattern of growth is approximately one foot per year shows a series of short increments, exhibiting bud scars that are tightly packed together, you are looking at a very unhappy plant.

(Continued in Mugo Pines 2)

(Photo credit: “Pinus mugo pumilio - Dwarf mountain pine" by Zeynel Cebeci, licensed under CC BY-SA 4.0.)