Famous for their highly fragrant flowers, honeysuckles are popular garden plants that are rarely seriously affected by pests or disease. Easy to grow and versatile, they include many species and varieties of climbing vines and deciduous and evergreen shrubs. Aphids, powdery mildew and honeysuckle leaf blight occasionally pose problems, especially for stressed plants growing in unsuitable conditions.
New shoots on honeysuckles are sometimes attacked by aphids, attracted to the soft, lush growth. Aphids suck sap from shoot tips, distorting growth and excreting sweet, sticky honeydew that then develops unsightly black, sooty mould. Honeysuckle aphids are small pale green or cream insects that cluster on shoots, living their whole lives on the plant and shedding white skin casts as they grow. Non-chemical controls include squashing small colonies with forefinger and thumb, and leaving to garden predators, such as ladybirds and hoverflies. Organic and chemical pesticides are also available, but aphid infestations are unlikely to harm established honeysuckles.
Honeysuckles with dry roots are susceptible to powdery mildew attack. A group of fungi that cause white, powdery coverings on leaves, stems and buds, powdery mildew species attack specific plant groups. Early symptoms show as small patches of white on leaf surfaces. Honeysuckles planted in dry areas next to walls and fences are especially at risk. Keeping honeysuckle roots moist by mulching with organic matter, such as garden compost or rotted leaf mould, helps prevent attacks. Once an infection is established, pruning out infected areas, removing dead plant matter, and frequent watering can help limit damage. Fungicides containing chemicals such as myclobutanil or difenoconazole are suitable controls.
A disease first reported in the UK in 2000, honeysuckle leaf blight causes pale leaf patches that turn yellow-brown, then silvery. A white bloom appears on the under leaf surface and leaves become distorted, often falling early. Stems aren't affected. Most widespread in the south of the UK, honeysuckle leaf blight appears in spring on new leaves as they emerge. Control involves improving air circulation by reducing congestion and overhanging foliage, removing dead leaves and spraying with copper fungicide.
Strong plants growing in suitable conditions are least likely to succumb to attacks from pests and diseases. Honeysuckles prefer well-drained soil and grow in full sun and partial shade. Honeysuckle vines growing in shade are less prone to aphid attack. For strong growth, feed plants every spring with a slow-release balanced chemical fertiliser or blood, fish and bone. Prune honeysuckle vines and shrubs to ease disease-prone congestion and remove damaged and dead growth.