Sphaeropsis Knot Fungus on Holly Trees

If you have any holly trees in your landscape you are encouraged to check them for Sphaeropsis tumefaciens – a fungus that causes galls to form on twigs and branches and witches brooms.  If let alone, can cause tissue necrosis and die back of growth, and in severe cases, death of holly trees; especially East Palatka varieties.  This disease starts on the lower branches and proceeds upward to the crown.

So how do you control it?  Fungicides don’t appear to be effective.  The best treatment requires removal of infected branches well behind infected tissue.  You must also disinfect your pruning tools between each cut by dipping the cutting blades in either bleach or alcohol.  Failure to do so can easily spread this disease.  It is also best to treat your plants when they are young.

Click here to learn more about this growing problem.

About AskthePlantMaster

I have 50 years of horticultural experience, am currently a Master Gardener in Central Florida. In addition, I'm a Horticulture Instructor and retired Parks Manager and Arborist. I love plants and would love to help you with yours!
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