by gardening_guru » 01 Nov 2008 21:51
Hello Ben,
From what you have told me, I would suspect that your conifers have been attacked by some kind of air borne fungul spores that will probably have entered through any wounds on the plants such as pruning cuts.
Make sure your secateurs are sterile, then cut out the dead bits. Promptly cut out any further brown shoots that develop and if it is such a fungul disease you might save the plants by cutting out the affected shoots quickly.
George aka The Gardening Guru