Dense colonies of aphids may be found along stems or on the underside of a leaf. They are drawn to succulent new growth. Several generations may occur and populations can build up quickly. Aphids are sucking insects which draw great quantities of sap, causing leaves and stems to become distorted. This distorted growth may be mistaken as herbicide injury.
Some plant sap is excreted as honeydew, which makes the plant sticky.
Sidewalks, cars, and patio furniture may become wet with honeydew. A sooty mold often grows in the honeydew and blackens stems, leaves and any other surface. Aphids may transmit plant pathogens. Wash off aphids with a steady stream of water. Avoid heavy applications of nitrogen fertilizer which can encourage succulent plant growth.