We've been dealing with some extremely wet weather here in North Florida over the past few weeks with both tropical storm Debby & Beryl. After Beryl, I noticed that A LOT of my once beautiful bushy yarrow had died - in fact, there was only a small top 'layer' of leaves that hadn't yet turned brown. So I began cleaning out the dead leaves & found what looked like white cottony fungus growing where the stems meet the soil, as well as on top of the soil.

I cleaned it all out, cut off any leaves that had the 'fungus', added fresh soil to replace what I'd cleaned out and went on my merry way, thinking I had fixed the issue.

Well, the fungus is back again and I'm wondering if anyone has any suggestions as to how I can get rid of the fungus - you can see it towards the right side of the pic I uploaded. I try to garden organically as much as possible (hence cleaning out the fungus rather than spraying with fungicide) - is there anything organic that I can do to get rid of the fungus? I'd rather not spray the plant, but I've had it for many years and will spray a fungicide if I have to, to save the plant. Should I just go ahead & spray it with something like neem oil to rid it of the fungus?