Several shrubs and trees have died, slowly, over the last two / three years – viburnum, ornamental plum, mallow, japanese maples, fuschia – photograph shows fungus on the mallow, no sign of honey fungus fungi, bootlaces etc., – other symptom is deep cracking / splitting along branches. All are in the front garden and relatively close. Starts with die-back of parts of shrub/tree and continues. Any ideas or suggestions?
For instance, viburnum could have gone with dieback, plum with canker, maple with coral spot, mallow with lavatera dieback.
These diseases cannot be prevented and it is common to lose occasional plants. That they are in the same spot is more than likely a coincidence, unless the soil and site conditions tend to be wet, which favours these disease pathogens.
Another possibiltiy is the raising of the soil around existing shrubs which can encourage dieback.