w/o a pic.. its impossible to know what the problem is.. as such.. it is not advisable to apply any kind of chemicals.. or organic solutions ...

and it would sure help to know what plants your are talking about.. where you are .... and other pertinent info ...

just saying you have spots.. really isnt enough info ...

ken

ps: i cant think of many spot issues.. that involve bugs.. so ... at this point in time .... there is no pest.. to kill with pesticides .... [and listen you nattering na-bobs ... i am talking the usual common suspects .. no need to list all the exceptions to my general comment... lol]

Ken is right in that we need images and further information about your plants and your location before we can be of much help.

Ken, any product used to control a pest of any kind is correctly called a pesticide. Under that umbrella term are fungicides, insecticides, herbicides, miticides, rodenticides.....you get the idea.

Pinkrose is wondering about a pesticide that might be applied to control diseases that may be lurking in her garden.....a fungicide.

Pinkrose, it's not advisable that you apply a fungicide to deciduous plants about to lose their foliage. Fungal outbreaks are rather normal at that time; the leaves have already been cut off the supply system in preparation for leaf drop. Your best recourse is to clean up carefully around the plants as fallen leaves can carry the spores of fungal and bacterial diseases. This is also a good time to make sure that the cultural conditions are as they should be.

Common plant diseases build up resistances to fungicides quite quickly, making it all the more important that pesticides be applied only when absolutely necessary and only after the ID of the plant AND the disease is known.