|my mopheads (golden cypress) are turning brown. I thought it was from harsh winter, but has been getting worse all summer and spreading to others. Diagnosis? Treatment?
|'Gold Mops' false cypresses are susceptible to winter burn if they are situated in a site that receives afternoon winter sun. Usually the damage is trimmed off in the spring and the plants recover. If you have a problem that is spreading, it might indicate an insect or disease problem or a root problem. Be sure to carefully inspect the foliage for signs of insects or disease spores. If you see none, the problem is most likely a root rot and the only way you'll know is if you dig around the root system. Sometimes you can simply prune out the dead and damaged roots and the plant will recover - unless the damage is severe. I wish I could positively diagnose the problem, but it's nearly impossible to do so without an opportunity to examine the plant and its roots. Dig down and check the roots - healthy roots are creamy white inside; dead or damaged roots will be brown or rusty colored inside and may be mushy. I hope you can determine just what's going on with your false cypress.