Nature provides trees with everything they need to thrive and be healthy. If you want to get the same result you need to mimic these conditions.
You should definitely mulch the magnolia. To do this, use organic mulch in a layer 2 to 4 inches thick, depending on the material you choose. Mulch the magnolia in early spring and avoid volcano mulching.
This is a short recommendation and we will cover all aspects of this topic in more detail next. By the way, I have a great article on How to Plant and Care for Magnolia in Your Garden.
Mulching is a natural process because all the fallen leaves create a cover that does a lot of good for the trees.
The main advantage of mulching is to prevent the soil from drying out quickly. In the case of magnolia, this is especially important because it is a moisture-loving tree and in hot weather, the ground can dry out quite quickly.
The second advantage is to reduce the negative effects of too low or too high temperatures on the root system. In other words, mulch will prevent overheating of roots in hot weather, and in severe frost will retain the heat near the roots, which comes from the depth of the ground.
In addition, mulch provides better aeration of the soil and prevents the emergence of weeds. Also, organic mulch is additional nutrition for magnolia.
What to use as mulch?
The best mulch is organic matter. Among organic materials, there are some that are better suited for magnolia than others.
This is primarily true of pine bark. It is a good mulching material that has a long life span and is able, among other things, to protect against weeds.
A second good material is a compost. Compost can provide the magnolia with additional nutrients as well as reduce water loss in the heat. The main thing is to choose a good supplier who offers a quality product.
Next comes the pine straw. This material has one of the shortest lifespans, but it provides good air access to the soil. In addition, the aesthetic qualities of this mulch are quite high.
Wood chips or shredded bark from other trees will also work well for magnolia. The main thing is that these materials should be free from diseases and pests.
How to mulch?
The best time to mulch is immediately after planting the magnolia. In this case, the tree will benefit immediately, although you can do it at any time of year.
The layer of mulch should be between 2 and 4 inches. The finer the mulch, the thinner the layer should be.
For example, for compost or finely shredded bark, a thickness of 2 inches is sufficient. The same goes for fine wood chips.
At the same time, for a coarser fraction of bark, you can make a layer 3 inches thick. Pine straw can be laid 4 inches thick because it has excellent air exchange.
The area to be mulched should be the same as the drip line. Simply put, the mulch circle should be as wide as the magnolia branches spread.
Under no circumstances should mulch material be placed on the tree trunk. There should be a 1-2 inch gap between the magnolia trunk and the mulch. More on this in the next chapter.
The mulch should be renewed from time to time. In the case of pine bark, this needs to be done about every two years.
Pine straw requires the most frequent replacement. This should be done once or twice a year. Be sure to remove the old pine needles before putting in the new ones.
What to avoid?
The first thing to watch out for is volcano mulching. That is, you have to avoid burying the lower part of the trunk in the mulch. Otherwise, you might have problems with the tree.
The first thing that might happen is that the magnolia will start to penetrate its roots into this excessive pile of mulch. As a result, the tree will noticeably stunt its growth for a while.
The second thing that can happen is bark and cambium disease. In this case, you could easily lose the plant.
To avoid this, leave some free space between the trunk and the mulch. There should be a gap of at least 1 inch between the trunk and the mulch.
Also, the thickness of the mulch layer should not exceed 4 inches. This is especially true for finely shredded mulch. Otherwise, the mulch will block air access to the ground surface and mold will form as a result.
Do not use inorganic materials for mulching magnolia. This applies primarily to shredded car tires. Worse material for mulching than this is hard to find.