When ants invade your home or lawn, it can be tempting to reach for poisons or ant baits to nuke the invaders into oblivion. But when it's your vegetable or flower garden that the ants have moved into, bug poisons may not be the best solution. Those poisons can wind up in ant tunnels that wind around the roots of your plants, and eventually in the fruits or vegetables you eat. A better solution may be organic pest control. There are several organic methods to remove ants from your garden.
Fill a stock pot with 3 gallons of water and bring it to a rolling boil over a stove. Pour the boiling water directly over the entrance to an ant colony. The boiling water will kill all ants that it comes into contact with. This method works best in the early morning hours or right after a rainstorm when the queen of the colony is likely to be in the top two feet of the colony's tunnels.
Sprinkle a line of flour, cinnamon or boric acid (such as the kind found in Borax) around your plants. This creates a moat that ants will not cross to get to your plants.
Squirt vinegar around your garden or over your vegetables whenever you see an ant trail. Ants hate the smell of vinegar and the smell will drive them away from your garden.
Sprinkle powdered corn meal around the entrance to an ant colony. Ants will take the corn grit back to their colony and feed it to their queen and eat it themselves. The grit expands in the ant's stomachs and kills them. This method may take some time to kill the colonies. Corn gluten may be commercially purchased as an ant insecticide to accomplish the same result.
Release biological controls to reduce ant populations in your garden. Parasitic nematodes such as Steinernema spp., parasitic insects such as straw-itch mite, phorid flies or Strepsiptera and parasitic fungi such as Beuvaria bassiana are all solutions for fire ant control. You can purchase biological controls for ants at many feed and farm stores, garden centers or organic pesticide retail outlets online.