The magnolia is a beautiful spring tree known for its fragrant, lush pink or white flowers. The tree is native to southeastern Asia and the eastern United States. The magnolia is fairly easy to grow and comparatively pest-free, but it has an odd root system. Many trees have root systems that mimic a tree's canopy, branching out into smaller, thinner roots and supporting the tree by becoming as wide underground as the tree is on top. The magnolia's root system, however, is unusual and consists of only a few thick roots with little branching.
The Structure of the Magnolia Root System
The magnolia tree's root system is unusual but well-adapted to its native environment. In the southern forests it calls home, the magnolia tree typically is surrounded by layers of leaves decomposing atop its shallow roots. The roots take nutrients from this natural compost and sit quite close to the top of the ground, accustomed to a damp and nutrient-rich environment.
Establishing a Magnolia Tree
To effectively establish a new magnolia, it is important to consider the tree's root system. Choose your location carefully, since magnolias are very hard to move. Depth is not much of an issue, but the roots will spread out as wide as the crown of the tree, as much as twenty to forty feet wide, or wider. (The roots of old, well-established trees can radiate out hundreds of feet from the base, in all directions.) So plant your magnolia tree far away from the house and any sidewalks or driveway.
Plant new magnolia trees in the fall in southern climates and in the spring in northern climates. Spread a layer of mulch over any newly established magnolia and water it regularly.
Moving a Magnolia Tree
Magnolias do not like being moved. A tree's roots are how it gains moisture and nutrients, and tampering with the root system can kill it. If your magnolia tree has a trunk no larger than four inches wide, however, you may be able to move it successfully. Because the roots of the magnolia are shallow but spread out very widely, try to dig a hole as wide as you can to capture as much of the root system as possible, before you move it. Replant the tree in a wide, shallow hole, in a spot where the roots will have plenty of room to spread. Water thoroughly as it reestablishes itself, because moving a tree is a shock to the root system.