Get some ladybugs in your garden, they will eat all the aphids.

dawn dish soap,(or any liquid dish soap) a 1-2 teaspoon in a spray Bootle rest plain water, shake and mix well. spray on any item in garden also works great on roses too. not harmful to plant or humans. just rinse veggies well before eating

1) Ladybugs, you can buy them from biological supply companies 2) Put/place a plant with insecticidal properties in the vicinity of your chives and onions

Spit tobacco juice on the plants, works every time....Mail pouch is a good brand name!

Malathion

two good methods. 1) Ladybugs, They love aphids. 2) Take a cigarette and break the tobaccoo into a pint of water and let it sit for a couple hours, then spray it on the plants, aphids hate tobaccoo.

Aphids usually aren't much of a problem on onion family or veggies unless there are flowers involved. Don't use any poisons on them as that can only make it worse, especially for your next years crops. And Malathion itself isn't highly toxic, but if it gets into the human body it changes and becomes malaoxon, which is toxic. It's what made me chemically sensitive since 1977 just from one use in our pigeon and chicken house. And it isn't as safe as the government has been telling us. This page is pretty scary! http://www.chem-tox.com/malathion/research/ So, anyway, to remove your aphids, first try very strong sprays of water to knock them down. Often that is all that is needed. If they are persistent, a fine spray of soapy water solution made by mixing a teaspoon of dishwashing soap with a quart of water will hamper their ability to breathe through pores in their abdomens. Overwintering eggs of fruit tree aphids can be destroyed with the application of a dormant oil spray after fall leaf drop is over. Edit: THought I would add something about natural pest control that works for more than aphids. * Squashing a few aphids around the infested plants releases a chemical signal that makes the other aphids drop from the plants and leave. * To foil aphids: flatten a square of aluminum foil around the base of plants to bounce light on the undersides of leaves. This also helps the plants in giving them more light. * Try a barrier of powdered charcoal, calcium dust or bonemeal to keep them away from your plants. * Stinging Nettle Spray: Aphids & Thrips - Cover 1 quart nettles with water, cover and ferment for 3 weeks. Mix 1 part nettle tea with 7 parts water. Spray. * Spread out a barrier of tansy around the base of the plant to stop those ants. * Use a spray made from a tea of tomato or potato leaves and water. * Chop 12 or so tomato leaves and 1 chopped onion in 1/2 cup of of 70% isopropyl alcohol for a few minutes. Apply the mixture directly on aphids with a cue tip or paintbrush. * A forceful spray of water is often enough to knock the aphids off the plant and may discourage the ants, well sometimes. * Put a bright yellow plastic pan in a strategic spot in the garden. Fill it a third of the way full with water. Aphids are drawn to the yellow color, land on the water, sink and drown. * A soap spray can be used to strip them of their protective wax coating, dehydrating them. Mix 1 tablespoon of Castile soap to 1 gallon of water, spray. * Garlic oil spray can kill aphids and other soft bodied pests. * A dusting of diatomaceous earth is lethal to aphids. Wear a mask when using DE. * Teas made from elderberry or rhubarb leaves can act as a deterrent. Oxalic acid is the compound present in these plants that makes a spray effective. It is poisonous. * Place banana peels at the base of infested plant. The peels give them a shot of potassium too! * For wooly aphids on apple trees: grow the trailing type nasturtiums training them to wrap up and around the tree trunk to ward off these pests. Very attractive too! Note: nasturtiums will specifically attract the black aphid while repelling others.