Armillaria is commonly called honey fungus, oak root fungus or shoestring root rot and attacks the roots of a wide variety of plants including azaleas.

It is usually spread by direct contact such as when the roots of an uninfected plant touch the roots of an infected plant or mulch that contains the fungus. In some areas, native trees carry the disease.

The best cure is prevention. This fungus is opportunistic and invades plants that are weakened by drought.

The best control is to make sure the disease is not spread to uncontaminated areas. Remove any diseased material and destroy it. Do everything possible to keep uninfected plants healthy. There is no chemical method of control according to every reference I have found.

If an area is heavily infected, it is often necessary to avoid planting susceptible plants such as azaleas, rhododendron, viburnum, rose, privet, apple and Prunus species. I have never heard of an azalea that is resistant to armillaria.

If you look into it eventually it boils down to almost nothing being resistant. Large colonies may cover acres, and get into the newspaper as World's Largest Living Thing. Said to be sensitive to dryness, making me think perhaps where I live at least being encouraged by irrigation practices needed to keep rhododendrons, azaleas and other moisture-demanding garden plants happy (July rainfall here in "rainy" Seattle area less than 1").

You are right on. When I moved to the east coast, most people here had never heard of or seen irrigation systems except in pictures in science soils classes. If we get a drought, people cry for government disaster aid.

In the west you look for irrigation rights first and then the property. Property without irrigation rights is called prairie land. People didn't ask if it had rained, they asked how good the snow pack was in the mountains so they knew they would have irrigation water.

It seems that many rhododendron nurseries in Oregon prefer misting equipment. Perhaps that is because of the low humidity as well as the dry summers. Our summers are so damp we get dew just about every morning which turns into steam by afternoon.

jimtex3000, I suspect I have had the same problem in my yard over the past two years, except I have lost numerous established antique roses, a large bottlebrush tree, and more. Who did you contact and send your sample to at A&M? Was there a cost involved? I would like to send a sample in as well, just to confirm the problem. Thanks, Carolyn.