Question
I have started a sweet potato vine inside of my home and most of the leaves are covered with tiny white specks about the size of sugar or salt grains. I cannot find any insect and the specks, which are easily scraped off appear to be damaging the leaves and spreading quickly. When I scrape the leaf with my nail, the specks appear to disintegrate and sometimes they appear to be turning black or at least leaving a black spot. Can you tell me what they are and how to treat them? Thank you.

Answer
Jeanne,

I think this may in fact be salt, which will leave black spots on leaves. Plants will sometimes exude salt if too heavily fertilized or if the roots are diseased. Try cutting back on the fertilizer especially if you are using liquid fertilizer.

Post a follow if you have questions.

Jack DeAngelis
http://www.livingwithbugs.com