Tar spot of maple

Symptoms

Late summer to autumn, raised, shiny black spots up to 2 cm across (like drops of tar) form on the upper leaf surface, sometimes surrounded by a yellow halo; heavily spotted leaves may drop early, but tree health is rarely affected.

Plants affected

• Red maple
• Sugar maple

Common questions

How do I recognise Tar spot of maple on Red maple?

Late summer to autumn, raised, shiny black spots up to 2 cm across (like drops of tar) form on the upper leaf surface, sometimes surrounded by a yellow halo; heavily spotted leaves may drop early, but tree health is rarely affected.

Do I have to report Tar spot of maple?

No. Tar spot of maple is not a notifiable organism, so there is nothing to report to an authority. Treat it as a normal garden problem.

How is Tar spot of maple treated?

Mainly with biological and cultural measures — removing affected material, changing the conditions that favour it, and treating with agents approved in your country. The exact steps and their timing depend on the plant, the season and where you live: Dr. Phyto works them out in a free diagnosis.