A frequently asked question at Wyatts Nursery, and nationally, is “What has happened to my conifer hedge, tree or bush? It has turned brown and does not recover.”
Recently planted conifers could be dying for a number of reasons, most likely water- related, but the main cause of death of conifers within the family Cupressaceae is the aphid Cinara Cupressi. Although the aphid is mainly associated with Leylandii, it can attack other conifers as well; namely Chamaecyparis, Cupressus and their cultivars.
The aphids attack the plant in Spring and are difficult and costly to control with aphicides. On small or medium sized bushes and trees it may be worth using an aphicide as soon as the pest is seen and well before yellowing of the foliage that precedes die back.
Research is being done by the RHS and the Conifer Growers Group to look at cultural ways to control the spread of this virulent pest. I suggest the following course of action:
• Make sure your conifers get a really good feed.
• Make sure your conifers are not short of water.
• Delay clipping until July.
• Change your choice of hedging to Thuja or a deciduous plant if starting a new hedge or replacing an existing hedge.
• PRAY for COLDER WINTERS!
For more help and advice or a site visit call John Wyatt on 07816 068323
Why are our conifers dying?
