When fig leaves start looking sad in late summer we get a lot of questions about what can be done. Figs are susceptible to a fungal disease called Fig Rust and it is not uncommon to see symptoms of this fungus on stressed trees.

 

 

 

Fig Rust symptoms begin as angular yellow-green flecks on the leaf. The spots become more yellow and eventually turn a yellowish brown.

 

 

 

 

 

 

 

 

On the underside of the leaf  the spots appear as small blisters from which reddish-brown spores are released at maturity. 

 

 

 

 

 

 

As the disease progresses the leaves become more yellow and the edges of the leaves become brown. In severe cases the trees may defoliate fully. 

 

 

 

 

 

What can be done?

Clean up, clean up, clean up! The best thing to do for all foliar fungal diseases is to rake up and bag diseased leaves on site. Dispose of them in a land fill or burn them. Do not compost. Remove any severely affected leaves and bag as well. 

Do not allow overhead lawn irrigation to wet the leaves, as this will spread the fungus. 

Remove dense growth in the center of the tree to improve air circulation. 

Reduce stress on the tree by maintaining mulch 2″-3″ deep beneath the canopy and practice infrequent deep watering that does not wet the leaves. Keep mulch pulled back 6″ from the trunk.

Few fungicides are labeled for rust on Fig trees, and once you see the disease it is too late to treat it anyway. Since this is rarely a fatal disease, no chemical treatment is indicated.