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 ...

If your lime tree is indoors, the floor under the potted plant may become sticky. Also, honeydew may cause a plant disease called sooty mold. If left unattended, scale insects can cause leaves to ...

Q: I just bought a cherry tree and found it has red shiny spots on most of its leaf stems. I sprayed with a fungicide but see no result, those spots look permanent. Are they OK? Is there some ...

Q: I have a mature palo verde tree in my back yard that has what appear to be some kind of white scale on the trunk and several main branches — it almost looks like cement or mortar. On some of the ...

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 ...

We have a lime tree that we winter indoors. In March, the tree developed about 60 limes. Also during that time, the tree developed scale insects. We purchased a nontoxic solution, which somewhat ...