Gardeners often assume ants near strawberry plants are directly responsible for damage. However, the relationship is usually indirect, with ants acting as a symptom of a larger issue. While ants can cause some direct harm, their greatest negative impact stems from their association with destructive sap-sucking insects. Understanding this dynamic is key to protecting your strawberry harvest and maintaining plant health.
The Primary Concern: Ants and Honeydew Pests
Ants are most commonly found on strawberry plants because of honeydew, a sugary substance excreted by sap-sucking insects like aphids, mealybugs, and scale insects. This residue is a desirable food source, and ants actively seek out these pest colonies to harvest it. This interaction creates a mutualistic relationship: ants gain food, and in return, they provide protection to the pests.
Ants defend these colonies from natural predators, such as lady beetles and parasitic wasps, essentially “farming” the pests for their secretions. This protection allows pest populations to grow unchecked, increasing damage to the strawberry plant. As pests feed, they extract sap, causing leaves to curl, shoots to stunt, and overall plant vigor to decline.
These protected pest populations can also transmit plant viruses as they move between plants. Furthermore, honeydew coating the leaves and fruit encourages the growth of sooty mold, a black fungus that reduces the plant’s ability to photosynthesize. Thus, the ants are not the primary attackers but rather the bodyguards that enable the true destructive pests to thrive, leading to crop loss and plant stress.
Direct Physical Damage to Plants and Roots
Ants can cause direct physical damage to strawberry plants through nesting activities, though this is secondary to their role as pest protectors. Certain ant species establish nests within or immediately adjacent to the planting area, often in well-drained soil. The process of tunneling and excavating soil to create their nests disrupts the fine, shallow root systems of the strawberry plants.
This tunneling activity can lead to excessive aeration of the soil, causing rapid drying around the crown and roots, potentially stressing the plant’s underground structures. When a large ant mound forms close to a plant, the physical displacement of soil can also compromise the plant’s stability and access to moisture and nutrients. The direct impact on crop yield from root damage is generally minor compared to other threats.
Ants may also directly feed on the fruit, although this is almost always secondary damage rather than a primary attack. Ants lack the mouthparts to break the tough, intact skin of a healthy, unripe strawberry. Instead, they are opportunistic feeders that target berries already compromised by other pests, such as slugs, snails, or sap beetles, or fruit damaged by rot. By consuming the breached, sugary fruit, they accelerate the decay process and render the harvest inedible.
Targeted Control Methods for Garden Ants
Effective ant control focuses on eliminating the underlying cause of their presence rather than just the ants themselves. The most targeted approach involves removing the honeydew-producing insects that attract the ants. A strong blast of water can dislodge pest colonies like aphids from the undersides of leaves, immediately removing the ants’ food source and discouraging their attendance.
Gardeners can also apply insecticidal soaps or neem oil to eliminate the sap-sucking pests. Once the honeydew source is gone, the ants will quickly relocate because the strawberry plants no longer offer a reliable reward. This method addresses the root of the problem without needing to target the ant colony directly.
If direct ant control is necessary, physical barriers and targeted baiting offer safe solutions for an edible garden. Applying a light dusting of diatomaceous earth (DE) around the base of the plants creates a physical barrier that dehydrates and kills ants that cross it. For established colonies, a targeted ant bait station placed away from the strawberry patch is effective. Worker ants carry the slow-acting poison back to the queen and the nest. These methods minimize the risk of chemical contamination on the fruit while safely managing the ant population.