A forceful stream of water, such as from a garden hose, can wash aphids or spider mites from foliage. You need to repeat this spraying because many of those pests will return. Do not use this method on tender plants.
A hose-end sprayer filled with a mild detergent or insecticidal soap will remove many insects. However, this process must be repeated frequently to be effective. And you must be careful not to over-water because excess moisture can create a disease-promoting condition.
