I'm finally ahead of the ants! And since ants bring aphids I'm a bit ahead of them too. When I see that the ants have moved onto a plant, evidenced by them walking up and down the stems, I simply clear away the leaves around the stem where it meets the soil and glob some Tanglefoot on the stem just above the soil line. Tanglefoot is a waxy sticky mix of goop that they can not cross because their feet get stuck to it. Next thing ya know they're marching off to find another place to live.