Biological control of aphids

To naturally control aphids, encourage predators such as ladybirds, lacewings, ground beetles, earwigs, parasitic wasps, and hoverflies into your garden. Plant nectar-rich, flowering plants to attract them, such as buddleia, calendula, sedum, stock, sweet William and wallflowers. Get a head start by growing a small patch of nettles to shelter predators. Cut the nettles back when aphids appear in other parts of your garden to encourage the predators to seek them out.