Why Does My Firethorn Look Unhealthy?

Are the leaves, stems, and buds distorted and sticky?

Are the leaves pale and mottled?

Are the leaves stippled, covered with fine webbing?

Is the foliage covered with small bumps, cottony masses may be present?

Do the leaves and stems have holes?

Do the flowers have holes, and the leaves are rolled up?

Do the flowers and shoots wilt suddenly in spring?

Do the leaves and fruits have black patches?

Distorted stems, buds, and leaves are caused by aphids. These tiny insects can vary in color, green, pink, black, gray to completely white. They cluster under leaves and on growing tips where they feed on plant sap. Leaves, stems, and buds get distorted and later leaves and flowers drop from the plant. You can control them by washing them off the plant with water spray. Insecticidal soap should be used with severe infestations.

Lace bugs are flat, dark-colored insects with lacelike wings that feed on the undersides of leaves. They cause leaves to turn yellow, then brown, and eventually die. Treat plants with a commercial pyrethrin spray or dust if the damage is severe. Prevent problems by covering plants with row cover until they blossom.

Leaves stippled with yellow and webbed foliage is caused by spider 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, or pyrethrin as a last resort.

White, cottony masses, or brownish bumps on foliage and stems 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.

Webworms are major pests on firethorns. Webworms are caterpillars that feed on leaves and spin silken webs around leaves and stems. Young plants may die and the older ones can be seriously weakened. Break up and remove the webs and spray plants with BTK as soon as hungry young caterpillars are visibly feeding on it.

Rolled leaves are caused by Rose leafrollers caterpillars. These dark to light green or cream to yellow caterpillars feed on the enclosed leaves and buds. If the infestation isn't severe, handpick the rolled leaves with caterpillars. For severe infestations, spray plants with BTK as soon as hungry young caterpillars are visibly feeding on it.

Fireblight is a bacterial disease that causes new shoots to wilt, turn black or brown, and die suddenly in late spring. Between November and March, cut off affected branches at least 3 inches below the damaged area on affected firethorn shrubs. Discard diseased branches in the trash. Before each cut, disinfect the pruning saw or shears with a spray of household disinfectant. Plant resistant varieties of firethorn such as 'Lalandi'.

A scab disease caused by a fungus sometimes disfigures firethorn leaves and fruits. Spray berries with Bordeaux mixture when buds begin to swell and open and again 10 to 20 days later.

A severe windburn may damage firethorn foliage during the winter. Minimize damage by surrounding plants with a protective material such as burlap or agricultural fleece. Spray leaves with anti-transpirant to retard water loss.