Question
I planted my weeping cherry tree in April and it had grown beautifully until about 3 weeks ago; first noticed curling leaves--thought it might be aphids so sprayed with organic insect killer. Now other leaves are turning yellow (some tiny black spots on them); began picking them off in beginning but now there are so many, it would take awhile to pick them all.  Please help as this tree was a special gift from my daughter.
Thank you.
Yes, we've had a very try summer but we've been careful to water our flowers/plants and everything else around the tree is doing fine.

Answer
I would use a product called Bayer Advanced tree and shrub Protect and Feed. This contains an insecticide that will kill the aphids and a fertilizer to increase the overall health of the tree. You apply it to the soil around the tree and the roots will carry it to the foliage an twigs and when the insect feed they are killed. Here is a web link to this product--check with your local garden type store for it.   http://www.bayeradvanced.com/tree-shrub-care/products/12-month-tree-shrub-protec