[header] How to control aphids [title] Spray the plants with a strong stream of water. [step] Use a hose to spray the plants affected by aphids with cold water-this should knock the aphids right off. A hard rainstorm can also wash the aphids off of the plant. 
[substeps] While you want there to be water pressure, make sure you don't damage the plants by setting the pressure too high. Repeat as needed to remove aphids when they crop up.