Hello, My very large maple tree has been diagnosed with ARMALLARIA and will have to be taken down. After I do this and grind the stump woud I be able to replant a Japanese Maple in it's place? A Katsura tree? An Ash? Or would the soil be contaminated and the disease would attack the new tree? I would appreciate your input and advice. WW
Ash would be a poor choice even if resistant due to Emerald Ash borer in Eastern North America. http://www.emeraldashborer.info/faq.cfm Here's a list of Resistant and Susceptible trees and shrubs. http://www.mastergardeners.org/pdf/Armillaria-list-2008-06-16.pdf
Thanks Saltcedar, I'm thinking of replacing the Armallaria diseased maple with a Katsura but I can't find it on any list. Do you have any info about a Katsura's resistance? WW
If you read long enough you find nothing is fully resistant except maybe turf grasses and yew trees. If you want another tree there you really should dig through the soil and remove all wood fragments of any size and any rhizomorphs ("bootlaces") encountered. After that I would let the spot bake in the sun for at least one summer, without mulching present - honey fungus is said to be adversely affected by drying of the soil.
Armillaria species exist in soils almost everywhere, and A. ostoyae is a pretty big issue facing the mature Garry Oaks of Victoria these days. The answer lies not in resistant cultivars, but in minimizing stress on your plant in most cases. Proper planting, adequate watering, good soil structure and nutrients, proper juvenile structural pruning, etc. Pre-emptive avoidance of Ash is completely unnecessary. Evidence that EAB will be a threat in the PNW is unsubstantiated; you have a much better chance of losing any one of our native species to a number of pressures than losing an Ash to EAB in the PNW.
We're talking about relative odds of plant necrosis in selecting a plant. The odds of EAB wiping out Ash in the PNW are lower than a newly planted Katsura being trampled by young adults coming home from the bar. I assure you, this is not the first case of insect pests that are devastating elsewhere being transported into the PNW in firewood. The insect has more than likely found its way east via shipping crates originally landing on the pacific.