Aphids are multicolored insects that inhabit your garden's soil and feed off your garden's plants in order to thrive and breed. The insects are commonly found in weeds, and while harmless when there are few in the soil, they can cause extensive plant damage by inhibiting plant growth including yellowing, curling and disease. The key to eliminating them from your soil requires chemical control to kill current infestations and removal of weeds to prevent more aphids from making the soil their home.
Spray the infested plants and weeds with warm water using a garden hose. Once aphids are sprayed off the weeds and plants, they will no longer be able to latch onto the plant.
Pull out the weeds to remove their natural habitat. Wear gardening gloves to protect your hands during the weed-pulling process, and burn the weeds to kill the insects.
Spray the plants with neem oil or insecticidal soap to kill adult aphids. Spray the top and underneath the leaves to eliminate aphids that are hiding deep within the weeds or plants.
Create a homemade insecticidal soap. Mix 1 tbsp. of canola oil, 1 to 2 squirts of dishwashing liquid soap and 1 quart of water in a spray bottle. Spray the solution on the plant to suffocate the insects.