I know it's humid here in Houston, but all season long it's seemed sunny enough not to worry about mildew, rust, or blackspot, and I really don't want to spray. The plants look tough enough. So I didn't think I'd need to ask my neighbor to do much more than water them for the two months I'll be away this summer. Then I saw this on Sunday:

I had topped off their containers with fresh potting mix and a little bloodmeal and perlite, then dressed them with hardwood mulch on Thursday, and everything was fine. I don't know if the mold might have been in the mulch or potting mix or in the big plastic tub in the shed that I tumbled the dirt in before adding it to the containers. It's possible, but I suspect that it came from my roommate's dead ivy houseplant, which had a similar mold growing on the soil-- she left the thing outside in the yard for several days while I was away because she didn't want to walk ten feet to chuck it herself. Grrrrrr.

I've been spraying the mulch and dirt with neem oil, but I don't know if it's helping. I also read that the mold could be benign, or it could even be that microrhizal fungi stuff that's beneficial for the roots. How to tell??? The leaves look unaffected so far, and for some reason the plant in the middle of the row doesn't seem to have any mold (it's mulched); neither do the plants that aren't mulched. So do I:

1) not freak out, let it resolve itself, maybe water less

2) buy more neem oil and ask neighbor to continue soil treatments

3) scrape the mulch and topsoil off (although I worry that'll just disperse more spores)

4) treat with another organic method

I have to clear my room out and pack and prep for this long spell away. I can't repot now even if it was a good idea.