I would think that the quantity of neem oil needed to treat heavily foliaged shrub/trees like crape and loropetalum would make it cost prohibitive.
With the aphids on crape, generally a strong water spray with a bit of detergent added can be done more frequently and with more effectiveness as it also washes off that 'honeydew' that attracts the black fungus that is so unsightly.
Be careful, whatever you do during this extremely hot weather when the plants are already stressed.

Okay, thanks.

A landscaper came by last night and looked at my crapes. Funny I didn't notice it, but he saw they were loaded with aphids and black spot immediately. He told me what to do they next couple of weeks to get them back perky again. He said they'll be alright.

He said they (his family are growers) do a light mix of oil and pesticide combined, and they always look great. Must work for them 'cause they sell a ton of shrubs and trees.

I mix a small amount of Neem Oil with water and bio-soap. I don't use it full strength. Don't spray it on any fuzzy leaves, tender leaves or blooms. Some chartreuse leaves may be too tender, too. I wouldn't use it on hydrangea leaves, for example. The glossy, thick leaves such as on a rose bush or crape are fine. Only spray late in the evening to prevent burning from the sun. Lightly. Very lightly.

Cameron

Thanks for the tips.