Green caterpillar infestation devastates boxwood plants across Denmark

A surge in demand for pest control products has followed widespread reports of the box tree moth caterpillar stripping hedges and potted plants, Danish broadcaster DR reports.

Garden centers in North Jutland are fielding desperate inquiries from homeowners after the bright green larvae—growing up to 4 cm long—have defoliated boxwood shrubs in a matter of days. Martin Holmriis, co-owner of Gug Anlæg og Planteskole in Aalborg, told DR that sales of the insecticide Larvex have tripled compared to last year, with shelves nearly emptied.

“It’s been completely wiped out in these past weeks,” Holmriis said. “Right now, we’ve got maybe two boxes left.”

The caterpillar, identifiable by its vivid green color and black stripes, can consume half a mature boxwood plant in under 48 hours. Mild infestations may allow recovery within a year, but severe damage leaves plants leafless and stunted for multiple growing seasons.

Holmriis advises affected gardeners to blast caterpillars off plants with cold water or apply Larvex—if supplies remain. For long-term solutions, he suggests replacing boxwood with alternatives like bloombux, a hardier ornamental shrub.

“Given how aggressive this pest has become, boxwood might not be the future of Danish gardens,” he said. “The question is whether we accept some damage as part of biodiversity or double down on fighting it.”