Question
dear dr vann

my small magnolia tree appears to have diseased leaves;
the underside has several bits of what looks like white rice grains (cooked)
the other side has a browning but also a blackening

i have some digital photos i could send to you.
my thinking is it may be scale insects, but i'm not sure.

can you help? and how can i treat it?

i live in the east of england, lincolnshire on the coast
and the tree is in a sheltered corner, with a clay soil
i've used sulphate of potash earlier, because it didn't flower much this year.

yours

philip jones

Answer
Philip:
A photo may be helpful for an ID.  Try to get as close as you can to make the photo and be sure the image is crisp and in focus by reviewing it on your computer before you send it.  A blurry photo is of limited value.

The black stuff that you mentioned- take a wet paper towel and wipe the leaf.  Check to see if the black comes off with a little wiping.  If it does, this is sooty mold, a fungus that grows on the sugary excretement of an insect. The cure for the sooty mold is controlling the insect.

You may have an insect, but getting a positive ID will help find a satisfactory remedy.  Are these "white things" too numerous to remove just the leaves that have them present?

Regards
Steve