Last year’s outbreak of Downy Mildew infected a large portion of San Diego’s Red Apple ice plant. Red Apple has been a main staple of the San Diego landscape for years. Primarily it is used on slopes along roadways and surrounding properties.
Downy Mildew is a fungus that preys on the bright green ground cover. The result is a blanket of brown, dead and dying plant material (and upset property managers) wondering what happened to their green slopes.
Some San Diego landscapers attempted to replant the Red Apple or took the opportunity to plant more drought tolerant ground cover. Others applied fungicide. This tended to prevent future outbreaks of the fungus more than cure the affected plant material.
With wetter, cooler months approaching, it’s imperative to take steps to prevent Downy Mildew outbreaks.
Preventative measures to be implemented by your commercial landscape manager:
- Minimal use of overhead irrigation during the evening hours
- Thinning nearby trees and shrubs to increase light and improve airflow. This allows the Red Apple leaves to dry faster following irrigation
- Fungicide application before infection occurs
To summarize, a proactive approach is the best way to prevent an outbreak. Landscape managers should ensure proper growing conditions. They should also apply preemptive fungicide applications in October and November once the weather cools.
If you would like help with your property’s Red Apple needs, please contact Heaviland Landscape Management at firstname.lastname@example.org