Dumbest thing I've ever done to a plant that nonetheless survived:
Years ago, shortly after I bought it, my Aspidistra elatior developed an infestation of some sort of soft scale insects. They washed off easily with soapy water, or with an alcohol spray, but they always returned. I had recently been reading about horticultural oils, so I decided to experiment. I sprayed the leaves of the plant with PAM®, the cooking spray. This actually worked in a sense, because the scale never came back. However it took months of frequent washing before I got rid of the nasty, sticky, oily residue the spray left on the leaves. It would seem like I had gotten it all, then I'd come back and they'd be sticky again. (Not unlike what was happening with the scale, now that I think of it.) I'm surprised that the plant survived. It's roughly 10 years old at this point, and has had numerous ups and downs, but it always rebounds.
Aspidistra elatior, and Aspidistra elatior variegata. The plain-leaved plant is the one that survived the oil spray. I learned that even if it is called "Cast-Iron Plant" it shouldn't be treated like a frying pan.
Something nice that I wasn't expecting:
My beast of a Monstera deliciosa is actually two plants in one pot, consisting of the original plant grown from seed, and a second plant produced from a cutting of the original. There was another cutting that didn't take permanently; it rooted, but rotted out shortly after I planted it in the soil. The nice surprise was that after taking that failed cutting, the original plant produced two new growing points that have both continued to put out new leaves. So I got the benefit of having a third plant in the pot, anyway. I had been under the impression that vining Aroids do not branch, but continue after cutting with a new, single header.
Dumbest thing I've done to plants that didn't survive:
Around the same time that I was spraying cooking oil on my Aspidistra, I was attempting to grow some plants from seed. One type that germinated surprisingly well was Philodendron bipinnatifidum (aka P. selloum.) So I had a whole bunch of seedlings growing tightly sealed under a plastic dome (the kind that rotisserie chickens come packaged in) in 100% humidity. They all had one or two sets of true leaves, which were scalloped just like the immature foliage of larger plants. So cute. So what do I do? I take the dome off, intending just to leave it off for a few minutes for air circulation. But I got distracted by who knows what, and when I came back, all my seedlings had collapsed beyond recovery. Sigh. I never tried Philodendron seeds again. My current P. bipinnatifidum was bought as a small adult plant.
I expect that I will be making more posts like this from time to time, as life among the leaves is full of amusing/appalling/surprising mini-moments.