Garden staff are finding more scale insects and aphids than in past years. A major infestation of lecanium scale was recently found on a large planting of bald cypress at the Garden. The population of ...

My magnolia had a problem with magnolia scale last year. Will it come back, and should I take some action to protect my tree? The leaves were covered in a black mold late last summer. — Frank Butler, ...

Q. I have half a dozen piñon trees that have scale and are looking rather brown and brittle. I have been watering these trees about twice a week for the past three weeks. When is the best time to use ...

One insect problem on trees and shrubs that seems to go unnoticed until it is almost too late is scale. It goes unnoticed because the signs are not always evident during the growing season. So fall ...

Facilities Management (FM) Outdoor Services will conduct a broadcast spray application of a dormant oil insecticide to nine oak trees over the winter break, weather permitting. These trees are ...

Maple trees in urban environments show signs of stress due to the urban heat island effect. Impervious surfaces like pavement retain heat and disrupt water absorption, stressing trees and making them ...

correctionIn an earlier version of this article, the last name of a Smithsonian Gardens arborist was incorrectly stated. He is Jacob Hendee, not Jacob Hender. The article has been corrected. Spring ...