Sounds like overwatering(common when flushing). Several things you can do to help, have air blowing across the soil(help it dry), Water with 1-part Peroxide to 5-10-parts water(creates extra oxygen(for the roots)) and as last a resort, I have stabbed my soil with my PH tester to aerate the soil(sort of like the roto-tiller). But a warning on that: damage to the roots can start the rootrot process, I've never dealt with this but I never have the same girl for long(2-3 mo's till cutdown).