Magnolias have a compact habit with a beautiful and dense crown. At times they can also form various bizarre growing shoots. Depending on the variety, magnolia trees reach an impressive height and width as they age. Corrective cutting is sometimes necessary. A cut back is then quite possible and not particularly difficult. However, a few things should be considered so that the beautiful natural growth habit is maintained and the tree is not damaged.
Pruning magnolia tree
Reasons for a cut
Normally, magnolias are quite hardy to cut. However, pruning can cause problems with wound healing, which in turn can lead to pathogens being able to quickly invade. Ideally, magnolias, such as witch hazel or various types of snowball, do not necessarily have to be cut back. However, there are sometimes reasons where a corrective cut is appropriate, such as:
- Tree has grown too tall and wide
- Lack of space, impairment of buildings, lack of light, etc.
- after storm or other weather damage
- in case of illness
- to quickly increase the flowering splendor
- Pruning immediately after planting
time
As with all other flowering shrubs, pruning, if at all, right after flowering to take place. At this point, the plants are full of sap and leaves. Wounds caused by the cut then close quickly, so that pathogens such as spores and fungi have no opportunity to penetrate the wood. The best time is
- early summer just after flowering
- depending on the variety from the end of May to the beginning of July, late bloomers to late summer
- in the fall only in an emergency after damage
Cutting back in early spring before flowering should be avoided at all costs, as frost damage can still occur. Most of the time, the magnolias recover only with great difficulty. Autumn is not good either, as the plants here have a hard time coping with pruning and cut wounds do not close for a long time. Furthermore, the formation of flowers may not occur in the following year.
No annual cut
Magnolias are very slow growing. The abundance of flowers increases steadily into old age. The reason for this is their acrotonous growth. New shoots are constantly formed from the end and upper side buds of the branches, which at the same time leads to an even crown structure with strong branches in the outer crown area. After four to five years, an optimal flowering stage is usually reached and then becomes obsolete very quickly. In principle, therefore, should all three to five years one taper cut take place, which ensures a new flowering splendor. However, an excessive maintenance cut must also be avoided here. It would just rob the magnolia of too much power. If several twigs and branches are to be cut off, several years should be planned for this. Of course, however, diseased and dead branches can be removed annually.
tip: Magnolias in pots must not be cut back. Only dead and diseased branches are removed here.
Sharp cutting tool
Always use sharp cutting tools to cut magnolias. The branches must not be crushed and cut surfaces must be smooth to prevent the ingress of pathogens from the outset. Best suited are:
- Pruning shears for small branches
- Pruning shears larger branches and clearing of the tree crown
- Pruning saw for thicker branches
- gloves
- eye protection if necessary
- fungicidal tree wax for wound sealing
tip: The cutting tools must be clean and sharp. Before and after pruning, these must be thoroughly cleaned with pure alcohol or a special disinfectant.
Maintain natural growth form
With every cut, care must be taken to ensure that the natural growth form of the magnolia is preserved. Therefore, restraint and caution is required. A pruning should strengthen the magnolia for the new flowering period and at the same time bring the wood into shape. Before starting the cutting work, it must be precisely determined which branches and twigs are to be cut. Removing too much can have fatal consequences for the tree. You shouldn’t just start cutting, but you should pay attention to a few things such as:
- only a limited number of new shoots sprout from old branches
- Avoiding one-sided stress on the tree, always cut symmetrically
- Cut off branches directly at the trunk so that the wound healing mechanism can start
- do not leave any branch stumps (avoid the penetration of spores and fungi)
- always cut to "astring" (slightly curved tissue directly on the trunk)
- If possible, cuts should not be larger than a two-euro piece (otherwise the wound will take a long time to heal)
- Wound closure with fungicidal tree wax for larger cut surfaces
- regular check of wound closures, close again if there are tears
- Do not crush shoots and branches
- Thin out the crown only slightly
- Cut away all inward and crossing branches at the base
- Either remove older branches completely or cut them off behind vital side branches
- Completely remove steep shoots (water shoots).
- Cut away competitive shoots to the main stem at the base
- in young plants never cut back more than a quarter of the leaf volume
- Remove dead and diseased branches regularly
- longer shoots can be diverted to lower ones (formation of new flowering shoots, plant receives more light)
- Using clean and sharp cutting tools
Excessive pruning can cause holes in the tree's habit. These then never close properly again. Stronger shoots should also never be trimmed to a certain length. Over time, more and more new branches would form here at the end of the shoots. Their direction of growth is uncontrolled in all directions. Ultimately, this would only further compact the crown.
tip: Shoots left over from pruning can be used to propagate cuttings.
Radical cut only in extreme emergencies
A magnolia does not easily forgive a radical cut. It should therefore only take place in emergencies and always remain an exception. A radical pruning after storm damage or in the event of an infestation may be necessary. The procedure is as follows:
- Scaffold shoots are all cut to three to a maximum of five shoots
- Cut away all shoots that are crossing and growing inwards
- leave more and more shoots on thick branches
- Wound sealing with fungicidal tree wax
- Use of sharp and clean cutting tools
After severe pruning, older branches must sprout again. This takes a long time. In general, this slows down the growth of the tree even further. In the worst case, even a radical cut cannot always save the magnolia.
tip: It can sometimes take two to three years or more for the tree to recover. In the following year there is no flowering.
Pruning after planting
It is advisable to carry out a pruning immediately after planting a young magnolia. This stimulates growth and natural branching. But even a cut to build up must be carried out professionally so that the tree is not damaged. Only a few steps are necessary.
- Pruning takes place in the spring after planting
- Shortening of all main shoots by a third to a maximum of half
- Cut a few millimeters above the outward-pointing shoot bud
- thus the extension of the main shoot does not grow into the interior of the crown
- Cut side branches back to one eye
- Do not squeeze branches
- Using clean and sharp cutting tools
tip: The branches are still thin, which ensures good wound healing.
Magnolias as standard
Over the years, magnolias reach a stately height and width. This should be considered before planting. However, you don't necessarily have to do without these enchanting spring flowers in small gardens. On the one hand, the specialist trade also offers small varieties and on the other hand, a magnolia can also be grown as a standard. However, it is a bit more labor intensive and requires extensive maintenance:
- regularly remove all shoots along the trunk
- form shoots
- Removal of all branch stumps
- regular formation of unwanted new shoots (water shoots) on leftover branches
- if necessary, permanent removal of these water shooters
- Wound closure with fungicidal tree wax
- Shape the remaining branches over the trunk to a crown by regular pruning
- Regular pruning, especially for young plants
- Do not crush branches
- use sharp and clean cutting tools
tip: The specialist trade already offers tulips, purples and standard magnolias as tall stems.
Tulip Magnolia Magnolia soulangiana
Is a pruning necessary?
Ideally is usually no pruning at magnolias necessary. By cutting, the natural and beautiful growth form of the tree is disturbed. Of course, dead and diseased branches are an exception. You should remove these immediately. Improper pruning can affect the growth of the tree. In the worst case, it will slowly die off.
Without pruning, the abundance of flowers increases slowly, but steadily until old age.
Magnolias always develop new shoots with a heavily branched crown on their terminal and upper side buds. After four to five years, the optimal flowering stage is reached. After that, it also quickly becomes obsolete. After this time, if desired, a rejuvenation pruning can be carried out to rejuvenate the flowering shrubs, which will lead to new blooms. However, a pronounced pruning is not absolutely necessary.