After 50 years of scientific research one is not nearer the actual cause of soil sickness. The latest research with the aid of very scientific equipment and DNA analysis of bacteria and fungi has eliminated them as a possible cause.
One knows that sterilisation of the soil by steam or using chemical fumigants such as Methylbromide, Herbifume or Basamid will “fix” the soil.
For private gardens Basamid is an option. The powder is sprinkled over the loosened soil and watered in very well (Beware – not too close to existing plants). The dissolving powder becomes gas, heavier than air, and penetrates the soil. After a week the soil is dug over again to allow fumes to escape and after a further week roses may be planted.
Another easy practice to overcome rose soil sickness in existing beds is to sink a sizeable cardboard box about 50 cm x 50 cm into the position where one intends re-settling a rose, planting the bush with potting soil into it. Once the new rose has established itself and the cardboard has deteriorated the rose will not be hampered by whatever it is that holds back root development.