One of our cherry laurels developed some white stuff (I believe the gardner said it was spider mites) and some of the leaves lost color so he cut them off. The bush not has leaves only at the top. Will the others grow back as it looks funny now. The white stuff has gone to other cherry laurels. The gardner said he sprayed them with horticulture oil. Is that enough or should he spray them with something else ? How can I tell if he sprayed the other bushes as they look more white now than before while the origonal looks less white? Will the other effected bushes lose their leaves during winter or do I have until spring to address it,
Baltimore County Maryland
Based on your description this sounds like you may be dealing with white prunicola scale, a sucking insect. This insect is often found on cherry laurel. Here is more about it http://extension.umd.edu/hgic/plants/armored-hard-scale-trees-and-shrubs
This insect is often found on cherry laurel. Here is more about it http://extension.umd.edu/hgic/plants/armored-hard-scale-trees-and-shrubs
Here is some information on control. Prune out any dead or dying branches. You can scrub off the white scales with a soft brush. You can spray with a dormant rate of horticultural oil to manage light infestations which it sounds like you have done.
You will have to check for crawlers starting in May (there may be three generations and they are salmon colored) before you spray. Wrap some of the branches with double-sided sticky tape to monitor for crawlers. When you see the crawlers, spray with a summer rate of horticultural oil. Follow all label directions. Do not spray when temperatures are in the high '80s in hot weather.
If this is not what you are noticing send us photos of the whole shrub, affected foliage, and the white stuff.