My Poor Lemon Tree

[roscoeroscoe]

So, for the winter I moved our Meyer lemon into our little greenhouse under a grow light, and made the mistake of putting some of our hanging baskets in there too. Some days later, there's an explosion of gnats and the lemon's leaves are covered with black spots, the flowers are trashed with black fuzz, etc. Any suggestions? What could it be? I got rid of the gnats with neem spray and natural insecticide, what can I do to get the lemon back to healthy?

Signed, desperate in Albuquerque