Signs
Clusters of tiny black, green, yellow, white, or pink dots
Sticky residue on leaves
Treatments
First, isolate plant to prevent spread of aphids and repot with new soil
Most effective strategy: spray directly with 70% isopropyl alcohol (rubbing alcohol) every day until bugs disappear
Wash aphids off with a strong blast of water
Introduce ladybugs into your garden to predate upon harmful insects
Apply diluted neem oil to affected plants and keep out of direct sun until it washes off
Spray affected plants with soapy water (1 tablespoon liquid soap in 1 quart of water) daily until bugs disappear