I have read that neem oil as a foliar spray works to get rid of aphids. I have some neem oil, but am not sure how to prepare it for spraying. My sweet pea plants are infested with aphids.
Should I mix the oil with water or some other carrier?
Yes, you can mix the neem oil with water plus a little soap to allow the oil and water to mix. Add approximately four teaspoons of neem oil per gallon of water, plus a few squirts of mild dish soap. Simply shake and spray.
Also, it's best to apply in the early morning or evening to avoid burning the foliage in the bright sunlight.