So you have ants. But is it an ant or an aphid problem? Usually an ant problem is a symptom of an aphid infestation so check your plants for aphids and by controlling them, reduce the antsí food source. They feed on sugary food such as honeydew produced by aphids, scale, mealy bugs and leafhoppers. Aphids can be washed off with the hose, but if you do have ants, they may carry them back. Arenít they clever! For organic control of both ants and aphids, courtesy of Christchurch Polytech organic course students, see the Answerfile.
More Ant info .
Myrm's Ant Nest: UK website written by amateur ant enthusiast and Naval medic. Lots of detailed info based on personal research.
Henry Double Day Research Association: Ant Fact Sheet - "Ants can be, literally and metaphorically, irritating, but they are not a major pest. They have some beneficial characteristics: they eat small insect pests and have a part to play in the recycling of plant and animal wastes."
I spoke with a composting specialist, he recommended that I start a worm bed, he said you can get them with a spigot on the bottom. If you pour off the liquid from the worm bed, it makes an excellent foliar fertilizer. He said he used it on his roses and not only did the plants love it but it got rid of all of his aphids. He said it worked as a systemic, I donít know if it killed the aphids or just drove them away, but he said it worked well.