Sigh...my first year of container gardening is still going strong. I have about 25 pots on my patio, including tournament of roses bushes, hibiscus, vincas, multiple types of peppers, lantanas, amaryllis, and various garden herbs. My roses were on the far side of my covered patio in morning sun, but the leaves were burning up and drying up, and it wasn't producing blooms. My hibiscus were next to them, with sun from sunrise until around 4 pm. They were doing ok, but with many yellow leaves, although the blooms were fairly regular. Then my light pink hibiscus started dropping buds. They would open to about halfway, then the entire stem would yellow and brown up. Everything else is in full shade, with intermittent sunlight (max 1 hour a day) and flourishing (my peppers are producing like no tomorrow!!).

We had to rearrange the patio, and I moved everything into the shade about a week ago. The rosebush is making a full recovery - after a deadheading and a day or so it exploded with new leaf growth, and yesterday my first bud opened with many other buds in various degrees of growth and opening (although tiny blooms - but I'll take tiny roses as opposed to dead/burnt ones). My lipstick hibiscus have slowed growth, and are producing blooms half the size, half the color intensity but twice as frequently.

My light pink hibiscus on the other hand has completely stopped flowering. It has buds all over it, and they are all slowly turing yellow and brown and drying up.

I give everything fish emulsion once every 2 weeks, as well as flower/veggie/shrub specific food. They all get a deep water every day, roses and hibiscus twice a day. There are no bugs, I've checked extensively, and I'm hesitant to treat them with an antifungal if I don't have to. I've looked around the internet, and I've found that the intense heat can cause bud drop, but then why is the other hibiscus flourishing? The leaves and stems look healthy, and are a very vibrant dark green with the occasional yellow, but the dying buds make it look sick. I'm going to try the vinegar, but is there anything I'm not thinking of, or am I just underestimating the Az sun?