I have these ‘foam’ bubbles/clumps on my roses and yarrow. Are they harmful or should I remove them. The majority of my plants are native 90% and organic.
You have the very distinctive signs of Spittlebugs (Philaenus spumarius) which leave these frothy clumps on plants. According to the University of Wisconsin Horticulture, these bubbles are left along the stems by the nymphs which combine air with their secretions. The adults look like a little leaf hopper and can cover significant distances. The nymphs and the adults suck the sap from the plant, although usually do not do very much damage. It is recommended to use a strong spray of your hose to wash away the insects and the froth and keep an eye on the plant for their return. As with any plant, top dressing it with some compost and keeping it well watered during the hot days of summer will also help keep your plants healthy and strong.
June 3, 2024