AusBonsai

It it overkill using one of those fungicides that you dilute in water, as a precaution when your trees look perfectly healthy?

I ask because some of my trees are staying wet for up to 4 days after I water them and I'm a little bit paranoid about rot etc. I make sure the soil is almost dry before I water again but winter keeps the soil quite wet.

I guess the better question is.... On average how long do roots need to be completely wet before fungus and rot set in?

4 days is nothing to worry about. 4 weeks maybe...but I have had trees pretty wet all winter and they are fine. As long as your mix is good there's no need for fungicide. If you want you can tilt the trees so they drain better during prolonged rain.

Ok thanks!