Are there any bark mulches that deter pests

Gardeners often assume bark is merely a blanket against weeds, yet certain species carry hidden armour that unsettles unwanted visitors. Cedar is the celebrated example; its volatile oils release a sharp, resinous perfume that confuses moths, beetles and even the occasional slug seeking a midnight feast.

Fresh pine carries terpene richness too, though results are subtler. When spread thickly, the acidic crust deters vine weevil larvae and creates an uncomfortable crawlspace for cats and foxes. Cypress, much like cedar, contains natural thujone compounds credited with reducing mosquito activity around patios and paths.

Texture matters as much as chemistry. Finely shredded bark packs tightly, forming a splintered mat that earwigs dislike and which frogs find difficult to navigate; larger nuggets leave airy corridors where insects may regroup. A mixed grade, available through AHS LTD, lets you tailor the surface, sandwiching fragrant cedar fines beneath weighty pine chips.

Remember, pest deterrence is never absolute. Rain will leach oils, summer heat will scatter aromas, and populations may adapt. Renew the mulch each spring, rake it lightly after storms and resist smothering beds beyond eight centimetres, otherwise roots may suffer. With observant care, bark becomes both ornament and quiet sentry for the season ahead.