Meadows Farm & Animal Sanctuary is a social farming project of the Shiva Trust Charity. Being a 26 acre site, they have no shortage of room or use for wood chips. Their first load of wood chips that arrived via Arbtalk was put to good use, mulching around the bases of newly planted trees. This mulch will help keep the area around the trees free from competing weeds. In addition the layer of chip will retain moisture in the soil for longer. Therefore wood chips for planting trees can be considered a dual purpose exercise, and if the chips are free, even better!
When using wood chips for planting trees it is important to get the depth correct. Piling the wood chips around the trunk will have a negative effect leading to possible fungal infections due to the constant moisture on the trunk. Conversely, not enough will allow weeds to quickly find their way to the light. As a guide, we would recommend a depth of approximately 4 to 6 inches (10 to 15cm). Keep in mind that this will settle as the wood chips break down, and will need a top up from time to time to ensure the chips do their intended job.
Using Diseased Wood Chips for Planting Trees
There is a concern that wood chips from tree surgeons could introduce fungal pathogens from other trees. According to the RHS, studies have indicated that this is unlikely to be a problem in healthy trees, due in part to the chips being restricted to top later. Care should be taken not to work them into the soil however. It is recommended that trees infected with honey fungus, Phytophtora root rot, verticillium wilt, and coral spot, are best avoided when tree planting.
There is further concern relating to allelopathy. These are naturally occurring chemicals that can in theory leach into the soil. The purpose of these chemicals is to discourage/suppress the growth of nearby plants. It is not believed that this should generally cause much issue on already established plants. One such tree that demonstrates allelopathy is Walnut so this should be avoided as there are far better wood chips for planting trees. As a side note, in my opinion Walnut chips make a very attractive wood chip for decorative purposes.
Do Wood Chips Remove Nitrogen From Soil?
Yes is the short answer. Fresh wood chips will remove nitrogen from the soil during their decomposition. In the case of using them as a mulch for tree planting, the chips are only used as a surface mulch. Nitrogen depletion with therefore only occur at the very top layer of the soil surface.
