Redwoods browning out

[mikewhite85]

I treated these redwoods with Arborfos about 6 months ago. The hillside had been heavily irrigated for some time and I assumed it was root rot. I had quite a difficult time peeling away the thick bark in order to get to the xylem. The capsules did drain though so it seems that the tree did take the medicine...

Just wondering what your thoughts are. The trees did not improve at all. Maybe it was misdiagnosed? Definitely not bark beetles because we removed 2 adjacent redwoods and the wood shows no sign of them.

The trees are in Hollywood, CA. They are not native to the area but I do see a lot of healthy redwoods around.

 

[sac-climber]

Mike....if irrigation is the issue, that needs to get fixed first. Arborfos isn't a silver bullet. Also consider high soil salinity from nitrogen fertilizer or boron toxicity. What does other vegetation surrounding look like? Redwoods have the same symptoms for a plethora of abiotic issues. Drought stress to phytophthora basically look the same.

 

[mikewhite85]

Thanks, sac-climber. I did recommended turning down the irrigation when I first treated the trees. There are Xylosma and ivy underneath (healthy looking).

 

[sac-climber]

Thanks, sac-climber. I did recommended turning down the irrigation when I first treated the trees. There are Xylosma and ivy underneath (healthy looking).

Xylosma and Hedera are, unfortunately, poor indicators of landscape health. They both thrive in a variety of conditions.
Is this a residential or commercial client?

 

[CalTreeEquip]

Redwoods love lots of water. They love cool, foggy, wet climates and do not respond to smog well. It might be just too hot for them in that particular spot. Or maybe a neighbor is poisoning them. I have noticed in the last few years, cases of RW's showing signs of stress. This is very unusual.

 

[sac-climber]

Redwoods love lots of water. They love cool, foggy, wet climates and do not respond to smog well. It might be just too hot for them in that particular spot. Or maybe a neighbor is poisoning them. I have noticed in the last few years, cases of RW's showing signs of stress. This is very unusual.

They don't like lots of water in the root zone. They are highly susceptible to Phytophthora. While they thrive in a natural environment high in moisture, keep in mind that comes with eons of thick forest soil high in organic matter that regulates soil moisture.

I wouldn't say this unusual at all to see in an artificial landscape setting. Bare compacted soils & overzealous watering programs are the perfect prescription saturation. I could walk out my door and find about 10 examples in my own neighborhood.

 

[2dogs]

I live in an area within the redwood zone (Santa Cruz) where redwoods will not grow well at all. The soil here is only 18-24" deep and lays on top of a thick layer of clay. The root system is weakened and the trees suffer. What is the depth of your soil?