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 ...

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 ...

I noticed a wet appearance on a portion of my deck under a magnolia, and also a black growth on its leaves. The branches of the tree seem to have lumps on them. What is this, and what can I do to help ...

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 ...

Purdue Landscape Report: Christmas tree growers have been struggling with an invasive scale pest called Cryptomeria scale (Aspidiotus cryptomeriae), which is a serious pest of conifers. The scales ...

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 ...