The developing buds of a peony plant often display a dense cluster of ants crawling across the sticky, green surface. This sight frequently raises concerns that the insects are damaging the plant or preventing the flower from opening. However, the presence of these insects is a predictable event driven entirely by a sweet reward produced by the bloom itself. Understanding this natural occurrence can alleviate worries about the plant’s health and explain the bond between these two organisms.
The Sweet Secret: Nectar Production
The ants are attracted purely by a specialized food source the peony produces. This sugary liquid is known as extrafloral nectar because it is secreted by glands outside of the actual flower petals. The nectaries are located on the green sepals that encapsulate and protect the developing flower bud. The sticky coating visible on the buds is this nectar, primarily a solution of water and various carbohydrates. It contains sugars such as sucrose, glucose, and fructose. The plant produces this substance as the buds mature, regardless of whether ants are present to consume it. Once a scout ant discovers this accessible food source, it lays down a pheromone trail that guides other ants back to the bud for a feast.
Mutual Benefit: The Peony-Ant Relationship
Garden folklore suggesting that ants are necessary to “pry open” the buds is inaccurate. Peony flowers open naturally when they reach maturity, and they will bloom fully even if no ants ever visit the plant. The connection between the two organisms represents a case of biological mutualism, where each partner receives a benefit. The ants gain a readily available, nutrient-rich meal from the copious nectar secreted by the bud.
In return for this sugary reward, the ants provide the peony with an indirect form of defense. As they patrol the bud to protect their food source, the ants may deter or actively remove small, herbivorous insects that could potentially damage the developing bloom. They act as a security force, preying on pests like thrips and aphids. This defensive service helps ensure the peony can invest its energy into producing a healthy, undamaged flower.
Managing Ants on Peony Buds
Since the ants do not damage the plant or prevent blooming, intervention is generally unnecessary and potentially disruptive to this natural process. The ants will typically disappear on their own once the flower opens and the nectar production ceases. Applying chemical insecticides to eliminate the ants is not advised, as this can harm other beneficial insects and is an overreaction to a benign event.
If the goal is to bring cut flowers indoors without hitchhiking insects, a simple, non-toxic method should be used. After cutting the stem, hold the bloom upside down and gently shake or tap the stem to dislodge the ants clinging to the petals. For a more thorough cleaning, a quick dip of the flower head into a container of cool water will safely remove any remaining ants before the bloom is placed in a vase. In rare cases, a sudden swarm of ants might be drawn not to the peony nectar, but to honeydew secreted by a large aphid infestation, which would warrant a gentle water spray to dislodge the sap-sucking pests.