Are Oak Leaves Bad For The Soil?
Q: I want to make my own leaf mold. I plan to mow my leaves and collect
them for the winter to break down into leaf mold. But most of the trees are
water oaks. I’ve heard that oak leaves release certain chemicals that make it
hard for things to grow.
A: I’ve often read English garden experts extolling the value of ‘leaf mold’. I
understand your concerns but there are three common myths about tree
leaves/needles. Lots of folks believe pine needles acidify the soil. They don’t:
pine trees simply tolerate poor, acid soils better than other trees. You have no
doubt heard that walnut trees kill other plants growing in the vicinity. This too
is doubtful. Experiments seeking to prove the deleterious effects of walnut
leaves have not been definitive and do not represent real life conditions. Your
oak leaves have no bad effect on soil. You can pile them up and let them rot
with no worries. The resulting crumbly, black humus is leaf mold. This
material is simply compost made from decomposing leaves only, no lawn
clippings, no kitchen waste and no other green material is added to the pile.