Statements about the roots of apple trees cannot really be made across the board for all apple varieties. Depending on the respective growth form as an espalier tree in a pot or as a free-standing wild apple, the roots can reach very different dimensions.
What are the roots of an apple tree like?
Apple tree roots are predominantly shallow-rooted and sensitive to waterlogging. Root depth and circumference vary depending on tree size and variety. General rules of thumb regarding root size only apply to a limited extent, as the crown has often been influenced by pruning.
The apple tree as a shallow rooter with an aversion to waterlogging
Even if the roots of the apple tree do not usually run directly along the surface of the earth, it is still predominantly a shallow-rooted tree. Therefore, when planting your garden, you should also make sure that you do not plant rose plants and strawberries directly near the apple tree trunk, as they would grow poorly here. Apple trees are sensitive to waterlogging, which is why they should only be watered at weekly intervals, even in summer.
Rules of thumb regarding root size only apply to a limited extent
An old popular rule of thumb is that the depth and circumference of tree roots can be roughly determined by the size of the tree crown. In times of special breeding and stock forms, this only applies to a very limited extent. The roots of a small apple tree or a bonsai apple tree can reach a surprising size. Since the crown of the apple tree has often been trained into a specific shape through targeted pruning, the circumference of the roots can hardly be read from it.
Replacing an old apple tree
After a maximum lifespan of around 100 years, most apple varieties have reached their maximum. If you want to replace an old apple tree with a young specimen in the same place, this requires a relatively large amount of work. Since pome fruit does not grow well when planted after pome fruit, for such a project the entire tree root must be dug up and removed, and then the soil must be filled with new humus. Without heavy equipment, such an undertaking involves a lot of physical work, despite the rather shallow root depth of apple trees.
Tips & Tricks
Apple trees often need to be replaced not just because of their age, but because they do not produce the desired yield. It might be worth trying to graft the branches of high-yielding apple varieties onto the existing tree. In this way, the growth size of the existing tree can be used as a basis for several new apple varieties.
