What's eating my yarrow 'moonshine'?

Achillea 'Moonshine' is exceptionally pest-resistant — its aromatic silver-grey foliage deters most insects and mammals. Aphids are the most likely pest, targeting soft new growth. Powdery mildew (a fungal disease) is actually a bigger risk than insects in warm, dry summers. Deer and rabbits largely avoid it.

Occasional colonies on tender new flower stems and shoot tips, producing sticky honeydew; rarely serious as yarrow's aromatic oils limit large build-ups. Spray off with water. Yarrow itself is a companion plant that attracts aphid predators like lacewings and hoverflies, so natural control is usually sufficient.

Grazing on young spring foliage emerging from the crown; silvery slime trails and irregular holes. Damage is minor — mature aromatic foliage is largely avoided. Apply ferric phosphate pellets around crowns in early spring. Remove leaf litter and debris nearby. Slug damage rarely warrants chemical intervention on established clumps.

Ragged holes in leaves and petals, feeding at night; frass (dark droppings) visible on and around affected flowers and foliage. Set trap pots (flower pots filled with straw, inverted on canes) to collect and relocate earwigs. Low populations can be tolerated as earwigs also prey on aphids.