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Pest identification

What's eating my border forsythia?

Aphids

Signs: Dense colonies on new shoots produce sticky honeydew and cause leaf curl and stunted growth.

Control: Knock off with a water jet; introduce or encourage aphid predators. Apply insecticidal soap if colonies persist.

Four-lined plant bug (Poecilocapsus lineatus)

Signs: Circular sunken brown or tan spots scattered across leaves; worst in late spring in northeastern US.

Control: Hand-pick nymphs in early season; remove affected foliage. Pyrethrin spray as a last resort — damage is mainly cosmetic.

Deer

Signs: Stems and buds stripped, particularly in late winter and early spring before bud break.

Control: Deer-repellent sprays reapplied after rain; physical caging of young plants; plant inside a deer fence.

Keep border forsythia pest-free

Healthy plants resist pests best. Get the basics right:

Border Forsythia pests — FAQ

What is eating my border forsythia?

Border Forsythia is a robust shrub but aphids colonise soft new growth, and four-lined plant bugs cause characteristic brown sunken spots on leaves in US gardens. Deer readily browse young stems and flower buds before they open. Overall pest pressure is light; forsythia is considered one of the more pest-resistant landscape shrubs.

How do I get rid of aphids on border forsythia?

Dense colonies on new shoots produce sticky honeydew and cause leaf curl and stunted growth. Knock off with a water jet; introduce or encourage aphid predators. Apply insecticidal soap if colonies persist.

How do I get rid of four-lined plant bug (poecilocapsus lineatus) on border forsythia?

Circular sunken brown or tan spots scattered across leaves; worst in late spring in northeastern US. Hand-pick nymphs in early season; remove affected foliage. Pyrethrin spray as a last resort — damage is mainly cosmetic.

How do I get rid of deer on border forsythia?

Stems and buds stripped, particularly in late winter and early spring before bud break. Deer-repellent sprays reapplied after rain; physical caging of young plants; plant inside a deer fence.