Pure Neem Oil will retain its potency much longer if stored at about 40° F in a low light area such as a refrigerator.
 

Do not mix anything with Neem oil until you are ready to use it. Mix only the amount of Neem oil you will use in 4 to 6 hours.
 

A new batch of Neem oil, water and a little soap (according to the label) should be mixed each time you are going to spray.
 

The soap (dishwashing detergent) is used to help emulsify the oil. If no soap is used the Neem will not mix into solution with the water and spraying will not be effective.
 

Spray the complete plant including the top of the potting media. Spray benches, walkways and any surface over which an insect might travel.
 

A mixture of 1 oz. to 1 gallon of water should be used for spraying. A weaker solution may be used as a maintenance spray. It is impossible to give a definite schedule for spraying, however a "close eye" will help each person to adjust a timetable to maintain clean plants. You will probably not have to spray as often with Neem as with toxic insecticides.