Why Ants Invade

• Ants could build a nest almost anywhere in the yard or garden, but flower pots provide easy-to-tunnel dirt and the perfect conditions to "farm" insects. They carry aphid, mealy bug, whitefly and scale insect eggs from other locations into the pot, where they hatch and begin to multiply. The insects produce a substance called honeydew, which the ants feast upon. The ants not only bring the insects to the plant, but furiously protect them from natural predators.
  
  

Harmful Effects

• Even though ants don't actually eat potted plants, they can still wreak havoc in a short period of time. The insects that they protect cause extensive damage to the plant, especially since the ants make it difficult for natural predators to thin their numbers. They constantly move dirt in the pot which may uncover delicate feeder roots, causing them to dry out. If this occurs wilting and death of the small roots may follow.
  
  

Safe Eradication

• It is possible to eliminate ants from pots, but it must be done in a way that doesn't harm the plants. One effective method involves filling a container with a solution of insecticidal soap and water, then submerging the pot deep enough to cover all of the soil. Soaking the pot for at least 20 minutes will kill the ants, though it's a good idea to check the pot regularly to make sure their relatives haven't staged another invasion.
  
  

Prevent Reinfestation

• The best way to discourage ants from returning to potted plants is to create an inhospitable environment. Making sure that no food or drinks are left on the porch or patio is a must, as ants are always drawn in by free food. Existing colonies in the yard or garden can be eliminated by dousing with boiling water at the point of entry. Placing ant baits or borax mixed with honey in areas with high ant traffic is another effective way to eliminate the insects.