Yesterday, I went to check on my four tropical Hibiscus plants (Hibiscus rosa-sinensis), and I discovered to my chagrin, that my peach-flowered plant had aphids. I immediately removed them all from their spots in the window and brought them to my bathtub, where I sprayed them liberally with a soapy water solution. Even though only one showed signs of infestation, they are grouped close together, so I knew I had to treat all four. I decided to let them stay there overnight, and I would rinse them with clear water in the morning before returning them to the window.
So this morning I enter the bathroom, and I'm greeted with three out of the four in bloom:
Apparently being sprayed down with soap and being kept in total darkness for several hours is no deterrent to them putting on a cheerful show.
Here are a couple of closeups:
Interestingly enough, the orange highlights on the second flower are not visible to the naked eye, at least not my naked eyes. They only show up in photographs. In person this plant's blooms always appear to be a plain bright red.
I do have an Hibiscus with orange flowers; that is the one that didn't bloom, though it does have buds. Maybe tomorrow.
And for what it's worth, I don't find aphids as easy to eliminate as some folks say. A strong spray of water won't do it. Soap, either dish or insecticidal, works, though it usually takes repeated treatments. Occasionally, I follow-up with a systemic insecticide in the soil.