I have rows of leyland trees as barriers on my property. I would like to buy more, but have been told by garden nurseries that there is a blight (chancres) that is affecting these trees. Is this correct? Is there any treatment against this blight for my trees? Are there substitutes for the leyland cypresses that are more resistance to such blights? I recently had to remove my ash trees because of the Emerald Asian Ash Borer. Thanks!
We never recommend planting too many of any plant because if a disease or insect gets going, it could ruin the planting. Also, if one or two plants die, the look or symmetry is ruined. A more natural planting, with a mix of species, avoids those pitfalls.
There is no particular blight effecting Leylands. They get some diseases, just like all plants do. There is no species that has no problems whatsoever.
Some evergreen alternatives to Leylands would be arborvitae (Green Giant is popular), American holly, Southern magnolias, cryptomeria, white pines and spruce.
You might consider a tree that does not get as tall as Leylands, too. They get tremendous and cast a lot of shade.