Keeping in mind that Neem Oil products are harmful to Lady Beetles the best method of control of Aphids is understanding their life cycles. Aphids can overwinter in plant litter, cold does not kill them off. As a rule Aphids are more attracted to plants with lush green growth although they can also be found on other plants. The Aphid can start to produce live young almost as soon as it is born itself (Aphids as a rule have a total life span of 30 days except those that hibernate over the winter). The single most bestest way to control Aphids on plants is with a sharp stream of water, knock the wee buggers off your plants and they, being as they are quite dumb, will die before they figure out from whence they came.
You will see Aphids again, as the next generations move in to replace those that you knocked off and they can also be knocked off the plant with a sharp stream of water, but do not use a lot of pressure which can do damage to the plants foliage, as some have discoverd when they sprayed their plants with water under 45 plus pounds per square inch.
There are some that may tell you that because Lady Beetles are not listed as a target species of Neem Oil producyts it does not harm them. Lady Beetles are not listed because they are not targets and no one would test these poisons and then tell you that they will kill these beneficial insects, but research has been done and Lady Beetles were significantly harmed with very low applications of Neem Oil products.

Would you mind linking us to those studies, Kimmsr? I can't find anything that indicates anything like that and would certainly be interested in seeing the research.

Mind you, we aren't talking about soaking the beetles in Neem, are we? Or boiling them. ;-)

I have done that. We are not talking ridiculous nonesense such as soaking anything in, or boiling anything in, Neem Oil solutions.

Introduce some green lacewing larva to you aphids. Be prepared to say goodbye to your aphids. Easy, quick and natural..;-)

Thank you for your replies. I had not heard that neem oil was harmful to the lady beetles. I have discountinued using it while I'm releasing them. I haven't seen anymore aphids so far. Luckily I had onions planted around the collards I pulled out which I think may have helped keep them contained to that area. I have let out some lacewing larva out as well :-D

Research indicates that neem oil, when used properly, does very little damage to non plant eating insects. Just as we don't spray insecticidal soaps or even strong streams of water on our ladybugs, avoid doing so with the neem.

Neem needs to be ingested by the plant eating insect in order for it to work.

But, it should be used only as one tool in the quest over aphid control. Good horticultural practices, plant grooming, and other gardening techniques can all work to manage the pests. But don't be afraid to use the neem when the population seems to be tipped hazardously in favor of the aphids at the sacrifice of the plants.

http://www.neemamerica.org/PDF/Organic_Gardener-May1996.pdf

Here is a link that might be useful: Here's a good fact sheet about Neem

Research at Washington State University indicates that Neem products are toxic to Lady Beetles, especially in the larval stage. There are, of course, some people that dispute these findings, but we should always err on the side od caution. When carefully, and properly, used Neem can be an effective pest control, although the best pest control is to get the soil the plants are growing in into a good healthy condition so you will grow strong and healthy plants that are less susceptible to insect pests and then will not need to use these poisons.

Here is a link that might be useful: Neem and Lady Beetles