I am a new Mirai Live subscriber. Been involved in Bonsai for about 9 years. Was wondering if the community had advice to share about preventative spraying of conifers for fungal disease in spring and fall. For the last few seasons I have used Phyton 27. It’s because a bonsai nursery closest to me uses it, and so I followed suit. Thank you in advance for any insight.
Looks like a copper fungicide, how long have you been using it and on what trees?( deciduous, pine?). I need to do something on my trees for the first time ever.
I have used it on all my conifers for 2 seasons, 3 applications 2 weeks apart in early spring and mid fall. Sometime the junipers get small areas of what I believe to be “cedar-apple rust”. This seems to knock it down. But disease control is a real weak point in my knowledge. Happy for any input people may have.
It’s probably better in the long term to keep the foliage dry and prevent fungal problems to begin with.
I tend to alternate between a couple options to prevent resistance from occurring. I use 3336 granular which is systemic and something with imidicloprin and a copper based one. I simply rotate them throughout the season to hit all the bugs! Systemics are great in spring and fall to set trees up for summer growth and winter dormancy as a precautionary measure.
I find it interesting how much preventative insecticides and fungicides people use. I have some 1 quart spray bottles that I use on specific trees when they have an issue. My most recent issues were powdery mildew on some Norway maple. seedlings (the ones under the big tree also had it) and some sort of fungus on the bark of branch stub on fairly mature trident maple. The powdery mildew was sprayed with propiconazole (I’ll start earlier this year) and the fungus was brushed off and painted with dilute lime-sulfur. Not sure how I avoid all of the issues that others including local club members, seem to have - I guess I am lucky.
Thanks, you guys, for the helpful advice. I am learning to navigate the site and am reading helpful previous disease related posts also.
Chris- that’s good advice, I know that the healthiest trees have fewer disease issues, and I have wondered if I am overdoing the fungal spray, instead of using sparingly and selectively.
Marty- I have been reluctant to use lime sulfur spray because I’m afraid to bleach the tree’s bark and foliage. I use it to preserve deadwood, of course. Can you tell me more about how you apply as a diluted spray, and if your trees suffer any discoloration as a result? I think this might be a better preventative solution for me in the fall, especially on the junipers (I think I remember that dormant “oil” is damaging for junipers). I hate just broadly spraying so much chemicals “just in case”…
I brushed the diluted lime-sulfur on only the branch areas that showed signs of fungal infection. Probably an area of about 10 cm^2.
I use only organics if at all possible
My go to except for junipers is Neem Max by Bonide
Seems to work well as a fall and spring spray or as needed.
I did research what to do with the Junipers and it looks like a diluted lime sulfur application as a dormant spray would be one to use on them.
I don’t think it changes the trees color because it is diluted but I don’t have firsthand experience with it
Thanks Chris! That is very helpful.