Why Does My Heather (Calluna) Look Unhealthy?

Are the leaves distorted, yellowed, and stippled?

Are the leaves and stems covered with small bumps?

Do the leaves and flowers have holes?

Are the leaves yellow and dropping, growth is poor?

Do the leaves have reddish or pale yellow areas on their upper side and dusty orange blisters on the undersides?

Are the leaves covered with white powdery patches?

Are your Heathers growing leggy?

Leaves stippled with yellow are caused by mites. These tiny, spider-like pests feed by sucking sap from the underside of the plants leaves causing yellow flecking on the upper leaf surfaces. You can control spider mites by spraying plants thoroughly with water 2-3 times a day for several days. For severe infestations, spray plants with insecticidal soap.

Leaves covered by small bumps are caused by scales. These tiny, shelled insects often feed on the undersides of the leaves, causing an unhealthy appearance with yellowish blotches on the upper leaf surfaces. Scrape off minor infestations with your fingernail. Prune out badly infested growth, or use a soft brush and soapy water to gently scrub the scales off the stems. Control scales by spraying insecticidal oil during the growing season.

Holes in leaves and flowers are caused by Japanese beetles, pests that can seriously damage Heather foliage. Adults of these insects devour leaves, stalks, and flowers of nearly 300 plant species. Their larvae feed on the roots of the plants. Handpick adult beetles into a can of soapy water but make sure to wear gloves as Japanese beetles are blister beetles. Apply parasitic nematodes to the soil to limit beetle grub populations. Use pyrethrin powder or neem oil as a last resort.

Yellow leaves that die and drop usually indicate Root rot in Heather plants. This disease is caused by both fungi and bacterias. Poorly drained, overly wet soil promotes rot so choose well-drained sites and add organic matter to improve drainage. Remove and destroy infected plants. Solarize the soil before replanting.

Likely cause for these symptoms is a fungal disease - Rust. Provide good air circulation around plants by thining them. Avoid making leaves wet when watering. Remove and destroy all garden debris before spring. All infected leaves should be removed. Spray leaves with sulfur early in the season to prevent rust or to treat mild infections.

White, powdery coating on the leaves is caused by a fungal disease Powdery mildew. Powdery mildew usually appears in damp places. Encourage good air circulation around the affected plants by thining any surrounding plants. Water plants from bellow to keep foliage dry. Any affected leaves should be cut off and removed. Any commercial fungicidal spray will protect your plant from further infections.

If the plants grow leggy and weak, it may indicate soil that is too fertile for Heathers. These plants thrive in poor soil that forces them to develop deep, sturdy root systems. Too much nitrogen in the soil results in weak root systems and excessive vegetative growth. Do not fertilize heather plants.

If the whole plants have been eaten, most likely culprits are animals like rabbits or deers. Deer may leave only stalks where beautiful foliage once was while rabbits usually prefer nibbling on the young shoots. Barriers provide the most reliable long-term protection from animals.