So far, nothing with the ability to have roses budded on it has shown any greater resistance to Oak Root Fungus. There have been some interesting results in inhibiting the fungus from progressing by using fresh horse manure. The fungus grows in compacted, soggy, nitrogen deficient soil. Aerating the soil, increasing the drainage and metering the water to prevent the soil from becoming soggy, and the addition of copious amounts of fresh horse manure have seemed to alleviate the problems associated with both Armillaria and Downey Mildew.

The fresh horse manure not only has a great deal of readily available nitrogen (from the urine) but also high doses of bacteria. While I know of no "official" studies regarding the use of the manure for this purpose, anectdotal reports have shown improvment in several gardens where this treatment has been tried.