The benefits of mulch are well known. It helps to retain moisture, keep weeds at bay and contribute organic matter to the soil. On the other hand, too much mulch around the tree trunk can be a bad thing and here's why:
- Bark plays a crucial role in the overall health and function of the tree. Prolonged contact with mulch means, over time, the bark gets soggy and breaks down, allowing insects, fungi and other diseases to penetrate the tree.
- Smothering the tree with too much mulch can suffocate the roots. When the roots can't breathe, they can grow into the mulch rather than through the surrounding soil. This can lead to a shallow root system, reducing the tree's stability and ability to access soil nutrients.
- Tree roots can circle the tree trunk when there's too much mulch. This can eventually constrict the tree's vascular system, making it difficult for it to get the water and food it needs to stay healthy.
How to properly mulch a tree
- Before you mulch, remove all the weeds from around a tree.
- Instead of piling mulch against the tree, you want to create a mulch doughnut about 60-90 cm wide and no more than 5-7cm deep.
- Mulch should not touch the bark at all.