Explore Plants

Share

Ask Mr. Smarty Plants

Ask Mr. Smarty Plants is a free service provided by the staff and volunteers at the Lady Bird Johnson Wildflower Center.

Search Smarty Plants
    
 

Can't find the answer in our existing FAQs, submit a question to Mr. Smarty Plants.
Need help with plant identification, visit the plant identification page.

rate this answer
Not Yet Rated

Tuesday - December 16, 2008

From: Pasadena, CA
Region: California
Topic: Trees
Title: Trees resistant to Armillaria mellea, root fungus
Answered by: Nan Hampton

QUESTION:

We had to bring down a 200 year old oak which root system was compromised by Armillaria mellea. We were told the fungus is still present in the soil & it's advisable to plant a resistant species. We're looking to find a native (or non-invasive) faster growing tree that will do well in the hotter and hotter climate of the region and be able to shade the south east face of our house. Any recommendations?

ANSWER:

First of all, here is information about Armillaria mellea and similar fungi from the  U. S. Forest Service, Forest Pathology.org and the Integrated Hardwood Range Management Program of the University of California Extension.  The U.S. Forest Service and Forest Pathology recommend removing stumps and as many of the roots as possible of affected trees before planting new trees.  All three of the sources above agree that the use of resistant species is one of the most effective means of controlling the fungus.

The University of California Davis has a list of plants that are highly resistant to Armillaria mellea and there is an extensive list showing plants that are resistant, or susceptible, to Armillaria mellea from Chase Horticultural Research.  Many of the plants on these two lists are not native to California and North America and we would not recommend any of those.  However, here are ones that are native and occur in Los Angeles County, or an adjacent county, that we would recommend:

Acacia farnesiana (sweet acacia)

Fraxinus velutina (velvet ash)

Arbutus menziesii (Pacific madrone) and photo

Prunus ilicifolia (hollyleaf cherry) and photos

Sambucus nigra ssp. canadensis (common elderberry)

Shepherdia argentea (silver buffaloberry)

 

 

 

More Trees Questions

Norway Pine vs. Norway Spruce
April 28, 2010 - Dear Mr. Smarty Plants, Is a Norway Pine the same species of tree as a Norway Spruce?
view the full question and answer

Tree roots under concrete from Ft. Worth TX
February 10, 2013 - We bought a house that has 2 trees (I believe ornamental pear trees) within a concrete patio. I found info that said basically, remove the concrete. We can't do that now (although I have encouraged...
view the full question and answer

Need tree suggestions for a long, narrow strip in Folsom, CA.
January 18, 2012 - I live in Folsom, Ca. I have a long strip (50') of planting area about 2.5' wide at the top of a retaining wall to the fence behind it. I would like to plant alternating (2) trees down this strip to...
view the full question and answer

Dwarf golden cypress outgrowing their space
December 28, 2008 - I planted two dwarf golden cypress on opposite sides of a dwarf alberta spruce in a small bed by the front door. After 4 years I have to severely prune back the dwarf cypress in spring as they will sp...
view the full question and answer

Evergreen trees for Long Island, NY
September 20, 2007 - I live on across from the water on the north shore of Long Island. I would like the names of some hardy trees that are both native to Long Island and also NOT deciduous! I am finding it easy to find...
view the full question and answer

Smarty Plants's Facebook profile Support the Wildflower Center by Donating Online or Becoming a Member today.

Mr. Smarty Plants wants you to be his Facebook friend. Click the Facebook icon to add yourself to Mr. Smarty Plants list of friends.