A Mugo pine is an evergreen that can be as small as three feet and almost as large as 20 feet tall. They are easy to prune and control and are often pruned as bonsai. This type of pine naturally grows very low and very wide. Pruning efforts should retain the natural shape of the shrub and keep it strong. It grows slowly so it will likely only need pruning every couple of seasons. That said, the more often you prune your Mugo, the tighter it will grow together and the fuller it will look. When it comes time, here’s how to do it:
Prepare your tools. Make sure your pruning tools are sharp and clean when you begin. This will make for clean cuts and promote the health of the Mugo.
Prune at the right time. Mugo pines should be pruned in the springtime when new growth is forming. Mugo is the only pine that you MUST prune when it’s growing. Prune it in the fall and the parts you prune will not grow again. This may seem like it makes the process easier but what it actually does is make the shrub sparse.
Promote good growth. Remove any dead limbs as well as those that have become damaged. The idea here is to leave only live material that will continue producing needles. Dead parts of the plant either don’t have needles or they have needles that are a rusty red. When you cut the secondary branches, make sure you are cutting on a bias at about a 45° angle. Think of it this way: you can cut back to any shoot that has green needles or buds but leave the live parts alone if possible.
Make sure it gets good sun. You will want to remove at least two thirds of the buds (also called candles) from your Mugo. The best way to do this is to remove the largest ones first then let the plant rest. A week later, come back and remove the smaller ones. This allows more sunlight to penetrate the plant and promote a hardy, vibrant pine.
Just take a little off the top. It is very important to understand that unless you are removing dead material, you don’t want to prune past the candles if you can avoid it. Even if you do it in springtime you could irreparably damage the plant and even kill it completely by cutting too far in.
Following these simple steps will yield a healthy, vibrant conifer that will compliment any lawn or garden where it resides.