Magnolia trees are beautiful and dense, and can reach towering heights. You may be tempted to prune a heavily grown magnolia, but this plant generally doesn't respond well to heavy pruning. Removing too many branches can stress the plant, weaken it and make it susceptible to disease. If you need to cut dead or unsightly branches, do it in the spring or summer after the first flowering. Otherwise, avoid removing too many fronds to protect your tree from damage and disease.
Steps
Part 1 of 3: Remove Dead and Diseased Branches
Step 1. Prioritize dead or diseased branches over healthy ones
When dealing with a magnolia tree, removing healthy - even if not good-looking - fronds can cause more damage than anything else. You should never prune more than a third of the tree at a time, so always start with the branches that are dying or already dead.
When in doubt, act cautiously about what to cut. Magnolias are very sensitive to pruning. Excessive removal of the branches can damage the plant, reduce the flowering of the following year and make the magnolia more susceptible to disease
Step 2. Wait for the tree to bloom for the first time
Depending on the climate in your area and the variety of magnolia, the first flowering may occur in spring or summer. The next moment is the only one in which you can proceed with a more intense pruning.
- Do not prune your tree in winter or early spring, as this could prevent the magnolia from producing flowers the following year. Additionally, it may become more susceptible to disease.
- If you notice a diseased branch at a different time of the year, you can remove it to try to combat the disease. Be careful, in any case: this can still damage the tree or make it more vulnerable. Try to manage the disease before proceeding with thinning.
Step 3. Disinfect the shears before and after pruning
Clean the shears with disinfectant alcohol and wait a few seconds for them to dry. If you have to cut several plants, disinfect the shears between one pruning and the next.
Step 4. Cut off any dead branches near the trunk
Dead fronds are fragile and often do not produce leaves or flowers, even when the rest of the tree is in bloom. You may also notice slight differences in color from the rest of the shrub. Use cutting shears to remove the branch about 2-3 cm away from the trunk.
Dry branches need to be removed, no matter if they are large or small
Step 5. Look for any branches showing signs of disease
Discolored leaves and bark, dangling fronds, and rotting wood are all signs of disease. If the disease is limited to 1 or 2 branches, remove these branches where they originate from the trunk.
- If there are ulcerations (open cracks in dead wood) on the main trunk of the tree, it may be too late to carry out recovery treatments. Ask an arborist to check out the magnolia. It is likely that you are forced to remove the entire tree.
- Some common diseases of magnolias include wilted verticillium, fungal leaf diseases, or algal spots always on the leaves. In addition to removing the diseased trunk, you may also need to apply an anti-fungal spray or neem oil.
Step 6. Use a hand saw to remove branches that are larger than 5cm in diameter
Make a cut under the branch, about 45 cm away from the trunk. Only cut about a third of the branch diameter. Make a second cut starting from the top, about 2-3 cm further out than the first. If the branch gives way while you are cutting it, these cuts will protect the shrub, especially the bark, from damage.
- Once you have made these cuts you can remove the branches just above the branch collar. Leave approximately 2-3 cm of margin above the frond collar to protect the magnolia.
- The only time you should cut the branches so much is when they are dead or show signs of disease. Do not remove large and healthy fronds: it can damage the tree, causing the growth of weed shoots called "suckers" or "suckers".
Part 2 of 3: Controlling Growth
Step 1. Select the young and lower branches if you want to control growth
You may not be able to control the shape of the tree, but you can occasionally remove the younger fronds to prevent the plant from developing too much. Locate the plant's lowest fronds, which are 2-5cm in diameter.
- Watch out for branches that grow strangely or intersect with other branches. They are most likely to be removed.
- Firm branches or those that develop on top of the tree must be removed only if they are dead or sick. Removing large and healthy leaves can damage the tree and inhibit flowering.
- Since magnolia is so sensitive to pruning, it is a good idea to spread any remodeling or pruning activity over a period of 2 or 3 years. This requires a little patience, but the long-term results will totally pay off the wait.
- You can prune healthy branches immediately after removing dead and diseased ones following the first flowering.
Step 2. Trim new shoots with pruning shears for a more open tree
Look for small, young shoots that grow sideways from the main branches. They are usually very thin, tending to be less than 2-3 cm in diameter. Cut them off where they originate from the main branch.
Cutting off these new shoots makes the tree less dense. This way you will have a more open and beautiful magnolia. That said, only pick the small and young ones
Step 3. Cut the branches close to the trunk with cutting shears
Follow the length of the branch until you get to the trunk. Make the cut right above the branch collar, which is a slightly wider area where the trunk and branch meet. Leave approximately 3 cm above the branch to prevent disease.
Do not cut the branches to the end. Magnolia tends to produce "suckers," which are dozens of small shoots and fronds whose growth cannot be easily controlled. In addition, this germination can result in a shrub with an unpleasant appearance when compared with a magnolia that grows normally
Step 4. Remove the suckers from the tree
They are long, uncultivated shoots that grow where a branch has been pruned or broken, often developing in unsightly clusters. To remove them, remove the nascent ones with your hands before they do any damage.
Part 3 of 3: Perform Safe Pruning
Step 1. Wear protective gloves and goggles when pruning
The gloves will protect your hands from scratches and cuts, while the glasses will prevent splinters of wood from getting into your eyes. You can purchase these two items at a garden store or hardware store.
If you climb a ladder, you should also wear a helmet and ask someone to stand down there to check
Step 2. Prune the tree when the weather is dry, to avoid disease
Diseases can quickly infest a freshly cut branch, particularly if it is damp or wet. To prevent this from happening, opt for cutting the magnolia on a sunny, dry day.
Step 3. Ask someone to check on you, in case you need to use a ladder
Some varieties of magnolia can grow very tall, so you may need a ladder to reach the branches. In this case, make sure there is someone available to watch you so that you can be safer if you accidentally fall or get hurt. This person should also be careful not to position themselves where a branch could fall.
Make sure you climb a ladder in total safety. Respect the weight limits and make sure the ladder is safe and well placed on the ground before climbing
Step 4. Contact an arborist if the magnolia has many dead or diseased branches
You should be able to cut the lower branches yourself, but it may be a good idea to hire an arborist to take care of the tallest or thickest branches. A professional can certainly solve any type of problem that the tree may present.
- If more than one branch shows signs of disease, an arborist can help you care for the tree without having to remove too many branches.
- Arborists may also advertise themselves as pruners or landscapers.
