I have removed the knockout rose bush that has witch's broom disease and threw it into the woods. Must I remove the dirt that it was growing in? Now I want to plant daffadill bulbs in that spot. Is that possible without digging out all the old soil.? It is October 30, 2016
Diseased Knockout Rose.
Poking around at several websites, I came across some disagreement on soil removal. The mites which transmit the virus of rose rosette disease overwinter under bark so all mulch in that bed should be removed as well as all of the rose's roots. Here is a description of the steps you should take to prevent reinfection. http://www.missouribotanicalgarden.org/gardens-gardening/your-garden/help-for-the-home-gardener/advice-tips-resources/pests-and-problems/diseases/viruses/rose-rosette.aspx