Wood chip uses

Asked April 4, 2013, 2:14 PM EDT

Hi. We recently chipped up some large wood debris on our property: old oak, fir, and pine branches that had probably been sitting on the ground for a year or more. Looking for advice/caution on what to do with the chipped material. We have blueberries and wine grapevines, and we were thinking about placing chipped material around the base of each, but we're not sure if this will be helpful or harmful to the plants (i.e., if the wood chipped material is too harsh and not well enough decomposed). Looking for recommendations on best applications on our property and would love your thoughts. Thank you SO much.

Marion County Oregon

1 Response


Wood chips can be a good in-row mulch for wine grapes or blueberries to help control annual weeds (seeds don't germinate readily into the wood chip mulch) or to help conserve moisture. It is important to not put too much on at once (more than 3 inches deep is risky) as the plant roots may have trouble getting enough oxygen, leading to root death (this is especially a problem in blueberry). Another consideration is the type of material used and how it may lead to immobilization of any nitrogen fertilizer applied. Generally, wood chips have a high carbon to nitrogen ratio and thus immobilize a significant portion of any nitrogen fertilizer applied to the surface -- this will reduce the amount of fertilizer the plant "sees". For this reason you must carefully watch plant growth and add more nitrogen than you have in the past to compensate for this. In blueberries, this might be an additional 10% (as a starting point). Well established grapes don't need fertilization with N generally in our soils. Finally, blueberries prefer mulches with a lower pH; the chips you have should be of low to moderate pH so acceptable for use. In addition, note that the large the wood chips, the longer it will take for the product to decompose over time.

Best wishes,