Posted on by Maryland Grows
Basil downy mildew arrived in the U.S. (Florida) in 2007 and has been devastating Italian sweet basil crops in Maryland and other states ever since. The disease (technically a water mold) can only survive on live basil plants so it…
Read MoreCategory: Food Gardening Tags: Author:Dave Clement, Author:Jon, Basil, downy mildew
Posted on by Maryland Grows
Until last summer most people in Maryland weren’t aware of the new fungal disease infecting boxwood called boxwood blight. In 2011 professionals in the green (landscape and greenhouse) industry were informed of the disease but the outbreaks were scattered and…
Read MoreCategory: Lawn & Garden Tags: Author:Dave Clement, boxwood blight, diagnose plant problems, Diseases, trees and shrubs
Posted on by Maryland Grows
The group of small ornamental shade trees lumped under the name Japanese maples, Acer palmatum and A. japonicum, and their many hybrids, are very popular with gardeners and plant enthusiasts. Most of the questions we receive about problems with Japanese…
Read MoreCategory: Lawn & Garden Tags: Author:Dave Clement, Japanese maples, landscaping, plant care, Trees
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Leyland cypress (x Cupressocyparis leylandii) has a lot going for it. It’s fast-growing with evergreen, feathery foliage and a pleasing, slender profile. It makes an excellent specimen tree or screening plant. A cross between two Pacific coast species, the Leyland cypress thrives…
Read MoreCategory: Lawn & Garden Tags: Author:Dave Clement, brown branches, Leyland cypress, winter damage
Posted on by Maryland Grows
Dr. Dave Clement, University of Maryland Extension Plant Pathologist, explains two common diseases of this popular evergreen tree. Colorado blue spruce trees, although not native or adapted to Maryland, are commonly planted in landscapes for their attractive color and shape….
Read MoreCategory: Lawn & Garden Tags: Author:Dave Clement, Colorado blue spruce, conifers, evergreens, Trees
Posted on by Maryland Grows
We’ve recently received inquiries about oak trees declining and dying. People usually want to know if this is caused by oak wilt. Importantly, oak wilt is not known to occur widely in Maryland. Two common leaf diseases of oaks in…
Read MoreCategory: Lawn & Garden Tags: Author:Dave Clement, oak leaf problems, oak tree decline, oak wilt, oaks, Trees
Posted on by Maryland Grows
Southern blight is a plant disease that is active now in hot summer weather. It is caused by a fungus called Sclerotium rolfsii. This fungus has a wide host range including woody plants, vegetables and herbs, and ornamental perennials such as…
Read MoreCategory: Food Gardening, Lawn & Garden Tags: Author:Dave Clement, Diseases, Southern blight, Wilting