Mulching

Mulching with woodchips is the closest that planted trees will get to being in a woodland.

In a woodland there is a carpet of leaves and other tree detrius, that composts down to feed the Soil Food Web with organic matter. As man /machine/chemicals have not been near this area, there is present a healthy Soil Biology that helps compost down the organic matter. This in turn supports Mycorrhizal fungi that symbiotically extend the root system of trees.

This is why woodchips / leaf matter is vitally important with the health of soil/trees.

When applying, do not place it around the trunk (the tree needs the trunk clear of soil buildup/woodchips) and spread it 10cm (3 Inches deep) as wide as you can, ideally upto the spread of the canopy or further.

If you have several trees, do this with half and leave the others and see the benefit.

Mulch will create upto 15 times the Mycorrhizal Fungi activity over that which is found with a grass finish.

Do not use bark, it is too slow to compost down (and is more expensive), use Landscape Mulch, where a whole tree has passed through a woodchipper. Local Tree Surgeons sell this, ask for well composted (so the tannins have leached out and not too much Conifer (slightly acidic).