Beginner mistake--mold suggestions?

[I_I_am_not_a_cat]

I believe this is a Purple Leaf Sand Cherry that was a volunteer in my front yard. I put it into this pot in its native soil, maybe Spring of 2022 and it has been doing well.

Last week I grabbed my sprayer that was full of watered down fish fertilizer and started watering a few plants just to empty the container since there was some still in there from the last time I used it. perhaps you can see where this is going, but after watering a few plants I realized that there was mold growing on top of the liquid in the container. I immediately tried to rinse the plants I had already watered with an extra amount of clean water, but I missed the Sand Cherry.

Today it looks like the mold is growing from several places along the main trunk.

Lesson learned--empty the container every time you use it.

How can I fight the mold that seems to be coming from inside the tree? I have it sitting in direct sun and the soil is damp but almost dry according to my chopstick.

 

[KateM]

Those look like woolly aphids to me, not mold.
Try to knock them off with some insecticidal soap. They are quiet common.

 

[I_I_am_not_a_cat]

Those look like woolly aphids to me, not mold.
Try to knock them off with some insecticidal soap. They are quiet common.

Wow, I guess I really should have put my reading glasses on, lol. And stop jumping to conclusions...

Yep, I see it now. Thanks!

 

[Matt B]

Wow, that looks quite nasty. If it were mine, I would chop it to below the mold and start fresh. Even if you could kill the mold there, that area of the trunk will quite probably never look attractive.

 

[Betula1]

Haha ! Definitely not mould!! Its clearly woolly aphids - a kind of sapsucking insect, which can be squished or treated with soap solution ( or use a systemic insecticide if it persists.)
Beware of well- meaning but misleading advice on here!!

 

[I_I_am_not_a_cat]

Haha ! Definitely not mould!! Its clearly woolly aphids - a kind of sapsucking insect, which can be squished or treated with soap solution ( or use a systemic insecticide if it persists.)
Beware of well- meaning but misleading advice on here!!

Thanks, I removed them by gently scraping them away. If I see more, I will try a soap solution next.

 

[Matt B]

Totally missed them. It looked like mold to me, probably because I haven't had any exposure to this type of aphid. I suppose it's not a big issue here in Florida. Then, my eyesight is not the best, either.