Andrew Salisbury, Principal Entomologist for the Royal Horticultural Society (RHS) has shared how to keep aphids under control in a 2019 video for the RHS. Andrew said aphids are “sap-sucking insects” which can be found on almost any plant. They range from just one to seven millimetres in size but can cause considerable damage.
“Of course, earlier in the summer these aphid colonies can build up to large numbers and can actually cause plants to wilt and lack vigour.”
If you can see aphids on your plants, you may be able to remove them by hand.
However, bigger colonies may need a more aggressive treatment.
Andrew continued: “Aphids that are exposed on shoot tips and flower buds can be removed by hand.
Some organic sprays recommended by the RHS for aphids include natural pyrethrum, fatty acids or plant oils.
Plant oils and fatty acids are also less likely to impact aphids natural predators such as adult ladybirds.
You may have to apply natural pesticides repeatedly to keep your aphid numbers under control.
Always follow label instructions when using pesticides to ensure you don’t damage your plants.
For edible plants and crops, make sure the food is mentioned on the label and follow instructions closely.