The Best Time to Prune Magnolias So They Look Beautiful All Year Long
A flowering favorite that grows in most regions of the country, magnolias can be stately trees or smaller and shrub-like plants. Most types are generally low-maintenance, but once in a while they may need a little pruning. For instance, you might be repairing storm damage to a mature Southern magnolia, or maybe you need to shape a young sweetbay magnolia so it doesn't crowd a pathway. However, if you prune at the wrong time, you can lose flowers for the year ahead. Here's what you need to know about when to prune your magnolias so they'll look beautiful year-round without sacrificing any blooms.
When to Prune the Top Types of Magnolias
Among the most ancient flowering species, magnolias were keeping company with the dinosaurs. They've had a lot of time to evolve, so there's quite a bit of variety in the family. Some magnolias have multiple stems or trunks, and others, like the Southern magnolia, have just one trunk. Some are deciduous, meaning they drop their leaves for the winter, and some are evergreen. Although there are thousands of different magnolias, you’re probably growing one of these four that do best in home gardens. The pruning rules are based on when each of these magnolias flowers.
Hardy in USDA Zones 6-10, Southern magnolia (Magnolia grandiflora) does everything in a big way. It can reach 60-80 feet tall and it has enormous white flowers that can reach a foot in diameter. It grows symmetrically so little pruning is needed to shape it. In fact, it's best to leave the lower branches in place so they touch the ground and cover the dead leaves that this evergreen tree naturally sheds almost every day. If you do need to trim it, wait until after it finishes blooming in summer.
Saucer magnolia or pink tulip tree (Magnolia x soulangeana) has multiple stems and gets about 25 feet tall and wide in Zones 4-9. It's best to decide how many trunks you want to keep when this tree is young, and shape is so the trunks and branches don’t cross each other. Its pretty flowers appear in spring, so time any pruning to happen after the blooms have faded. Once this deciduous tree has matured at about 20 years old, prune as little as possible because it heals slowly.
Star magnolia (Magnolia stellata) will grow to 15-20 feet tall with multiple stems in Zones 4-8. It loses its leaves in the fall, and in spring the star-shape blooms appear on bare branches (plant it in front of evergreens or a dark-colored wall to really help the flowers stand out). Prune your star magnolia after it blooms to help shape it within the first five years after you plant it.
Sweetbay magnolia (Magnolia virginiana) doesn’t bloom until the summer. Another multi-stemmed magnolia that will need pruning guidance as a young tree, it’s the exception to the usual pruning time rule for magnolias. You need to catch this one at the end of the winter, before its growth spurt. Once it starts growing in the spring, you run the risk of pruning off the summer flowers for that year. Sweetbay magnolia will grow in Zones 5-10; it can be a small 15-foot, deciduous tree in New York or it can shoot up to 60 feet in the deep South, where it tends to be evergreen.
Pruning Tools and Tips for Magnolias
Your magnolia probably won’t ever need major surgery, unless a storm hits it hard or it got off on the wrong foot in its youth. With young magnolias, make cuts with pruning shears. If a small branch doesn’t fit easily inside your open pruners, you should use loppers instead, and be sure to grab a pruning saw for branches over one inch in diameter. And if you need a little extra help with this project, BH&G Local Services pros can help!