Ants in the Garden

Have You Ants in Your Garden? 

Many will know about ants as pests when they come indoors, and lines of them are found trailing into our larders and over kitchen work surfaces. But when ants are outside in the garden they may not be recognised as a pest.

Small numbers of ants in the garden are normal and will probably not be doing any harm. However, some invasive species can form very large colonies of many nests and some species can be significant pests in the garden, as well as when they find their way into the home or other buildings.

Ants as Garden Pests

• Farm Sap Sucking Pests - Ants in the garden can be pests when they ‘farm’ sap-sucking insects such as aphids, scale insects and mealybugs. These ants protect and encourage the sap-sucking insects in return for the honeydew that the sap-sucking insects produce. The honeydew is a sugary liquid from excess sap that provides the ants with an energy meal. The sap-sucking insects may proliferate under the ants’ protection and cause significant damage to the plants whose sap they are sucking.
• Kill Beneficials - Some species of ants, including Argentine ants, are pests because they attack and kill competing invertebrates in the garden, including beneficial insects. The reduction in insects and other creatures that would predate on sap-sucking pests, or that help in the decomposition and the natural breakdown of leaflitter, is damaging to the garden environment.
• Damage to Plants - Some ants will damage plants such as vegetables directly by chewing on soft leaves or roots.
• Bites and Stings - Some ants sting and/or bite and can be irritating when working in the garden. Thankfully such ants are not common in New Zealand; e.g. Argentine ants bite. There is a risk that other more harmful ants could be imported into New Zealand; the red imported fire ant has been found and eradicated on several occasions.
• Tunnelling – Ants tunnels can undermine plant roots, lawns, paths and driveways causing subsidence. However, the tunnelling can also be beneficial; moving nutrients deeper in the soil.

Controlling Ants in the Garden

If you have ants in the garden that are being pests in one or more of the ways above, you may want to control them and/or prevent their damage.

• Prevent Farming of Sap Suckers – The application of Kiwicare LawnPro Protect around the roots of plants acts as a barrier to ants climbing the plant and also controls the sap-sucking insects directly because the systemic insecticide is taken up by the plant roots and kills the sap-sucking insects as they feed. PLANThealth Spectrum spray can also be applied to the foliage.
• Protect Beneficial Creatures – Getting rid of ants, or keeping their numbers down, will encourage beneficial creatures such as ladybugs, earthworms and hoverflies. If ant nests can be identified, apply NO Ants Ant Sand to the nest entrance and about 1 metre around. NO Ants Ant Sand is non-repellent and will not cause ant colonies to leave the nest and spread.
• Prevent Damage to Plants - The application of Kiwicare LawnPro Protect around plants will act as a barrier to ants and protect the plants.
  Note: Insect Hit Granules should not be applied to the roots of cropping plants but it can be applied in a ring outside the roots of the plants.
• Stop Bites and Stings – Wear gloves when gardening in areas where biting or stinging ants are found. Shake out clothes, gloves, boots and shoes after they have been sitting in ant-infested areas. Insect repellents will also help keep ants away.
• Stop Undermining - Apply NO Ants Ant Sand to the nest entrance and about 1 metre around.

To stop ants entering your home or other buildings follow the Kiwicare 1-2-3 Ant Control Programme.

David Brittain
Kiwicare