FOLIAR FUNGAL DISEASES
This spring we had a long stretch of cool, very damp weather. This usually results in a number of fungal leaf diseases, including anthracnose in sycamore and ash trees, white oaks and sometimes in maples. We have also seen it this spring in linden trees.
Although anthracnose can cause a lot of leaf loss, or failure of leaf expansion, it is not a life threatening condition. It is a nuisance, with the necessity of cleaning leaves from your yard in the spring. It leads to concern among homeowners when the tree is quite defoliated, like many of the sycamore trees this year and when they pick up leaves with black spots and distortion.
In the great majority of cases, trees with significant defoliation will put out new leaves and by mid-summer will have a normal or near normal complement of leaves.
We do have some antifungal injectable agents that may speed or enhance re-foliation. Sprays are not advised because they could only work as a preventive application if applied before any disease development, not as after the fact applications.
PHOMOPSIS TIP BLIGHT IN JUNIPERS
This fungal tip blight has been more severe than usual this year, for the same reasons as noted above. Management can include pruning out the blighted tips and preventive fungicide sprays in the spring.
SOFT SCALE INSECTS
So far this year, we have seen some pockets of soft scale infestations in shade trees, both lecanium and cottony maple scale and some magnolia scale and fletcher scale.
Management of soft scale should be systemic, by trunk injection or soil application. Sprays could actually make the problem worse and will usually not make it better.