Gardeners often encounter ants around their potato plants, leading to the common term “potato ants.” Understanding what these ants are, why they appear, their impact, and how to manage them can help maintain a healthy garden. This article clarifies the nature of “potato ants,” their behaviors, and effective management strategies.
Understanding “Potato Ants”
“Potato ant” is a colloquial term, not a specific species, referring to various common ants found near potato plants or tubers. These soil-nesting ants adapt well to garden environments. Frequently encountered species include cornfield ants (Lasius neoniger), pavement ants (Tetramorium immigrans), and black garden ants (Lasius niger).
Cornfield ants are small, light to dark brown, often building visible, crater-like nests. Pavement ants are light to dark brown or blackish, identifiable by parallel lines on their head and thorax, and typically nest under sidewalks or stones. Black garden ants are small, shiny, dark-bodied ants commonly nesting in soil or under paving. These species share a preference for nesting in loose soil and are frequently seen foraging in gardens.
Why the Name “Potato Ant”?
The term “potato ant” arises from behaviors that draw these common ant species near potato plants. A primary reason is their nesting preference; many ants favor loose, well-aerated soil for their colonies, often found in cultivated potato patches. Ants may even establish nests directly within or beneath damaged potato tubers, utilizing them for shelter.
Ants are also attracted to potato plants as a food source, particularly through their symbiotic relationship with sap-sucking aphids. Ants “farm” aphids for honeydew, a sugary excretion, actively protecting these pests to ensure a continuous supply. Additionally, ants scavenge for food, and damaged, rotting, or exposed potato tubers can become an appealing source of carbohydrates and moisture.
Impact on Your Garden
The presence of “potato ants” in your garden can have varied implications, from neutral to problematic. While ants are generally not considered major garden pests, their activities can sometimes indirectly affect potato plants. Ants typically do not consume healthy potato plants or undamaged tubers. However, certain species, like fire ants, have been observed feeding on damaged potato tubers.
A more common concern is the ants’ association with sap-sucking pests. Ants protect and foster populations of aphids on potato plants in exchange for honeydew. Aphids weaken plants by sucking out sap and can transmit diseases, indirectly harming the potato crop. Despite these potential downsides, ants also offer benefits, such as aerating the soil, consuming other small insect pests, and contributing to organic matter decomposition.
Managing Potato Ants
Managing “potato ants” involves integrated pest management (IPM) principles, focusing on prevention and non-chemical methods. Good garden hygiene is key; promptly removing damaged or rotting potato tubers and spilled debris eliminates attractive food sources. Ensuring healthy, robust potato plants also makes them less susceptible to pest issues.
Non-chemical approaches are often effective. Applying food-grade diatomaceous earth (DE) around plants or ant activity areas can deter them. DE works by abrading ant exoskeletons, leading to dehydration, but loses effectiveness when wet, requiring reapplication. Some gardeners also use strong scents ants dislike, such as peppermint, rosemary, or cinnamon, sprinkled around plants.
If ant populations become a nuisance, targeted control methods can be employed. Placing outdoor ant baits can reduce colony numbers, as these are carried back to the nest, impacting the entire colony. Addressing aphid infestations on potato plants is also a key strategy, as eliminating their honeydew source naturally deters ants. Insecticidal soaps can control aphids, which in turn reduces ant presence. The goal is to manage ant populations to an acceptable level rather than complete eradication, as many common garden ants play a role in the garden ecosystem.