Aphids attack hibiscus plant, adversely affecting flowering

Hibiscus plants are ideal for those who cannot spend much time gardening since they flower daily.
However, a major problem which few mention, is that aphids can attack the plant, due to which the flowers do not blossom
They usually only attack the top most part of the plant , with the buds.
Soap water is considered to be one of the most effective ways of getting rid of the aphids.