The Japanese or Soulange magnolia, also called tulip magnolia, is a deciduous tree that grows up to 6-8 meters in height and produces large fragrant flowers in spring that resemble tulips. Due to the particular type of growth, it is very important that magnolias are pruned carefully, with the right tools and knowledge. Even one year of poorly done pruning can block the development of this beautiful shrub and prevent it from flowering. However, the correct way to prune magnolia trees is simple and easy to learn.
Steps
Part 1 of 2: Pruning to Strengthen and for Appearance
Step 1. Prune the magnolia once a year, in early spring
Soulange magnolias do not require extensive pruning, but rather some selective cutting when the tree is young, while an annual cleaning will help the tree develop stronger branches and a more pleasant shape.
Tulip magnolias should be pruned in the spring, after flowering. Never prune a tulip magnolia after early July, as the new flower buds for the following spring have already formed
Step 2. Always use sharp tools to prune a magnolia
The type of tool to use depends on the thickness of the branches.
- Small branches with a diameter of up to about one and a half centimeters can be pruned with manual shears that cut with an action similar to that of scissors.
- Larger branches (up to 5cm thick) should be pruned with anvil type pruning shears. A pruning saw should instead be used for branches over 5 cm thick.
Step 3. Prune the tree immediately after planting it
If the tulip magnolia is purchased as a bare root tree and some of the roots are damaged, prune about 1/3 of the canopy immediately after planting to help compensate for the reduction in healthy roots.
- Do not cut the tip on top of the leading branch or main trunk of the tree. Sharp hand-held shears can be used simply to cut branches about 1/3 of their length.
- Let the tree grow without pruning over the next two years.
Step 4. Prune the tree again two years after planting it
Two years after the tree is planted, some branches may need to be removed to improve the shape and structure of the tree.
- Take a few steps back and look closely at the spacing of the branches along the trunk and their angle. In fact, they should be evenly distributed along the length of the trunk.
- If some branches need to be removed to balance spacing, prune branches that have corners with tight bifurcations first. These tend to be weak and to detach easily from the tree in case of strong winds or ice build-up.
- Ideally, the branches should grow out of the trunk at an angle of 30-60 °.
Step 5. Use the correct pruning technique
Always cut just beyond the branch collar, which is the slightly raised area at the base of the branch. Do not score or cut the branch collar.
- Prune growing branches at the correct angle only as needed to balance spacing.
- Small green shoots can grow where the branch has been removed. If they appear, simply tear them off by hand, or pinch them off with your thumb if they are very small.
Part 2 of 2: Prune Damaged or Diseased Branches
Step 1. Prune damaged branches throughout the year
Branches that are damaged or broken need to be pruned whenever you notice them throughout the year. Remove the entire broken branch completely up to the collar.
It is not necessary to seal the cut with something. The tree quickly forms a natural barrier, and paint or tree wound dressing products can interfere with this process
Step 2. Remove the diseased branches
While tulip magnolias typically aren't attacked by common tree diseases, they can occasionally develop ulcers or cancers.
- When ulcers or small patches of discolored or oozing bark are present on a branch, the entire branch should be pruned completely to the collar.
- Remove the branch when the weather is dry to help prevent the spread of the disease.
Step 3. Disinfect the tools after clearing the diseased branches
Disinfect the shears with household disinfectant or a 10% bleach-in-water mixture before and after using them on the diseased branch.
- This will prevent the disease from spreading to other branches or even other parts of the garden.
- Always remove the disinfectant or bleach solution with water from the shears before using them.
Advice
- If you are pruning a young magnolia to create an espalier (a horizontally sized plant to be used as a decorative element for landscape architecture), it is important that you are diligent working on the shape of the plant when it is still young and tender. You should remove branches that do not fit the pattern you are creating with extreme injury, to allow the shrub to produce new growth in the correct areas.
- The emphasis is on choosing the right branches to cut when working on the shape. Choose branches that have wide rather than narrow angles, and encourage the plant to strengthen itself by using a suitable fertilizer and watering criteria.
