Aphids breed like crazy. One aphid can produce over 70 offspring within a week. They can destroy a plant before you even notice a problem. They need to be removed and quickly.
Tip #1. Spray the plant down with a strong surge of water. Once aphids are detached from a stem or leaf, they have a difficult time getting reattached. Blast the host plant 2 or 3 times within a few days.
Tip #2. Hand squish several aphids. This releases a chemical signal to the others, warning them of eminent danger. They will drop off your plant as a result. This will not rid your plant of all the aphids, but it will slow them down.
Tip #3. Create a bio diverse environment. Introduce insects that are predatory to aphids. The two best insects that will devour the aphid is the Lacewing Larvae and the baby ladybug. Both infant insects can eat aphids by the hundreds in just a few days time.
Tip #4. Cut off colonies by simply pruning the plant where the bulk of aphids are collected. Without resorting to a more powerful insecticide you may just have to amputate a portion of the overwhelmed plant.
Whatever methods of removal you choose to use, don’t wait. Any evidence of aphid invasion must be controlled as soon as possible, before an infestation can develop.