Answer to February
Horticulture Challenge

Wood-chip mulches tie up soil nitrogen and cause deficiencies in plants.
True or False

ANSWER: False. "Wood-chip mulches will not reduce the amount of nitrogen available to existing plants, whose roots are primarily below the mulch/soil interface.
This conclusion is validated by many studies demonstrating that woody mulches increase nutrient levels in both soils and plant foliage. Compared to the various other mulches studied, wood chips are superior choices in terms of the improved establishment and survival of urban trees and shrubs
Source: Chalker-Scott, L. 2010. "The Myth of Nitrogen-Nabbing Wood Chips." In "The Informed Gardener", 157-159. University of Washington Press, Seattle, WA

(contributed by Marie)