By Bendipa
Surrey,
United Kingdom 
I have a batch of new bare-rooted roses due within the next few weeks. I want to plant them where old rose bushes are, but am aware of the risk of rose replant disease. I've heard that using mycorrhizal fungus avoids the need to replace the top soil where old roses grew, but has this been prove? Has anyone tried this method with success? Otherwise there will be a lot of top soil that will need replacing
19 Oct, 2013
Answers
Bunny Guinness has been advising this for several years now.
There probably has been scientific research, if you've a mind to read the academic papers, but I would imagine that if rose sellers are saying it works then there's a good chance that it does (or people would be asking for their money back). I would probably go with the claims of the rose growers/sellers than with the fungus manufacturers.
ps a thick layer of cardboard in the bottom of the planting hole is supposed to help.
20 Oct, 2013
Joining in so as to see any answers if you don't mind!
19 Oct, 2013