Neem oil time is just starting, or rather the application of the nutty smelling oil is just starting. It took me a little while to understand this use of natural product, when to spray, how much, etc. As an oil it has a relatively low setting temperature, around 17 celsius, so its pretty solid for a lot of the year. My belief is that the time to use neem is when it is in liquid form, no need for microwaves or hot water, and the insects that attack our plants and pets are just getting "started" for the season.
My citrus trees have aphids as do the roses and orleanders. A general tell-tale is that there is much more wasp activity around the tree and small shiny parts on leaves. I will spray this afternoon/evening around 7pm -- it is much more effctive to spray in the afternoons, however wind can be more problematic. I will use 60ml neem oil mixed with 50ml of potassium soap for a 16 litre back-pack sprayer and make sure the plants get a good soaking. The addition of the potassium soap works as an amulsifier so pathways and drives don't get slippy with the application of an oil, or gravel doesn't stain with the tiny droplets of oil that are airborne when spraying. The same process will be repeated in around 14 days, this time, however, it is to combat Californian scale or piojo rojo de california