Root Rot

jnahnet · Jan 10, 2017

California drought has killed all of the Ponderosa Pines, Cedars, & Douglas firs. Now I'm losing Live Oaks and the Juniper to root rot. These are mature trees that are just falling over, the Juniper looked very healthy just before it toppled. The soil is full of white hairy threads. Afghan Pine seedlings have died near the Juniper. How can I replant if the soil is infected? Is there a recommended fungicide that can be used on soil and large areas.

Jason Douglas · Jan 12, 2017

Can you give us some closer pics of the tree base and the white threads?

Sounds like you are seeing mycellium or rhizomorphs of a root and butt rot, perhaps Armillaria...

Long periods of stress can certainly weaken a plants defenses to pathogens.

jnahnet · Jan 13, 2017

Jason, Thank you for your reply, it's supposed to stop raining tomorrow, I'll take close up pics. I'm afraid to start replanting until I can figure this out. I really appreciate any insights you might have.

Jason Douglas · Jan 13, 2017

Sure thing.

jnahnet · Jan 13, 2017

Jason, There are mushrooms growing near the tree, I shot samples of the dirt under them, samples of dirt at the base of the Juniper that doesn't have mushrooms and a shot of the cavity of the Juniper where it broke off, not much there but shattered wood. The whitish soil directly beneath the mushrooms has a very odd consistency (almost like styrofoam) the white treads running through the soil is from the base of the tree (not mushrooms). From what I've researched; if it's Armillaria, there's not much I can do?
Again, thank you so much for your experience, it's heartbreaking to lose 100 year old oaks and 60 foot Junipers.

Jason Douglas · Jan 14, 2017

Yeah those gilled mushrooms along with the mycellial mass looks like one of the Armillaria. Possibly another white rot basidomycete but it's kind of moot at this point.

Fungicides arent really an option so look into improving soil condition, never causing root damage and compaction in the future, and most importantly, researching tree species resistant to these fungi for future replacements.