Forestry Commission entomologists recommend that horse chestnut leaves are removed to lower incidence of leaf miner. However, Patch said contractors should not remove organic matter from soil in the following year.
He said: "Before using pest and disease control as an excuse for blowing leaves away from shrubberies, think about the pests and diseases that may be affecting the trees. For example, oak mildew will not be affected by gathering fallen infected leaves because the fungus overwinters behind the bud scales of the host tree.
"Leaves also provide overwinter protection for beneficial organisms, some of which are food for birds and mammals that do not hibernate."