Jena, my Perle d’Or did the bud drop thing it’s first year, the whole year. A lot of my roses also had chlorosis, including Perle d’Or, even though they were getting regular Magnesium-sulfate and I was alternating between Miracle Grown and a seaweed fertilizer, all in the hopes of curing them of chlorosis. Mostly it was the Polyanthas and Multifloras that had this problem. Finally I sent in a sample for a soil test. I had plenty of all the minerals and nutrients except for Nitrogen (which I already knew since its obviously devoid of any organics and so I was fertilizing) and absolutely zero Manganese (Mn) detected. Once I put a teaspoon of Manganese Sulfate dissolved in a gallon of water on each rose last fall the chlorosis completely disappeared and Perle d’Or stopped dropping buds. I will now do this once or twice a year; not too often since Mn is a minor nutrient and too much can be toxic. The Miracle grow I was using did have trace Mn, but somehow it wasn’t enough. I wonder if my soil was just binding it up? This just demonstrates that bud drop could be due to lack of an essential nutrient. It might not necessarily be Manganese for you. But since you mention the Kellogg soil might not be that great, I would give it a nice dilute liquid fertilizer once a week and see if it cures it.

BTW it is a Peperomia obtusifolia and not a real rubber plant. It would more light than its current location. It is possible that after watering the inner pot, it could be sitting in water inside the cache pot. Especially if the pot is not drained well before placing it back in the ceramic pot. I would at least put some pebbles inside the ceramic pot to keep the inner pot raised. Do the leaves perk up after soaking well? If it does it could under-watered.

What's most "common", by a very, very large measure, is to do what I described. In fact, it's very uncommon for hobby growers with trees/plants in containers to try to identify and isolate a deficiency then treat it, and when they do, it's usually because they were influenced by someone with good intentions. To suggest something is good or right because it's 'common' is a logical fallacy called 'appeal to tradition'. Grand theft, cheating on your taxes, driving while impaired, or choosing junk food over healthier fare, are all "common". It's worth repeating what I said above about hobby growers adding this and because someone said it would be good for my plant. The effort usually end up being limiting, not beneficial. There is no substitute for a sound nutritional supplementation program, and 99.999 hobby growers will never achieve one by dosing with elements/compounds chosen because they provide 1 or 2 nutrients. "To go through all of the above instructions each and every time a deficiency occurs seems quite unconventional, unnecessary, and frankly far from the norm." Poisoning the well by suggesting what I described is somehow a laborious chore that must be repeated with great regularity is very misleading. Mixing the fertilizer solution requires no more effort than mixing a solution of water and Epsom salts. You flush the soil thoroughly ONCE, one time. Then, you fertilize with Foliage-Pro 9-3-6, which ensures every nutrient essential to normal growth is A) in the soil solution, and B) immediately available for uptake C) at a ratio extremely favorable to the plant. After that, Amy needs only to water appropriately and fertilize regularly - standard care. The suggestion to simply dose with Adding Epsom salts does nothing to correct any existing nutritional problems not related to Mg, and has a significant potential to add to whatever problems might exist. What I suggested ensures she'll be on solid ground with regard to all nutrients. It's always important to remember that anything in the soil solution in excess of what the plant needs has only the potential to limit the plant; and an excess has the same potential to be limiting as a deficiency. IF, we were talking about trees in the ground or an orchard, "appropriate" would be having a soil test done and adding the nutrients suggested by that soil test facility. I can't imagine an orchardist looking at a few leaves, determining the cause is a Mg deficiency, then start spraying Epsom salts on the leaves. Without tissue analysis to confirm nutrient deficiencies pro growers are very often dead wrong in determining what's causing symptoms to appear in leaves, and that's when they have the leaves in hand and a history of the plant. Here, we have another hobby grower diagnosing from an image in the internet with no cultural clues or background and writing prescriptions for a cure, when the wisest thing by far would be to get the plant on a sound and very easy nutritional supplementation program ASAP. Finally, you're asking Amy to bet with you that the most limiting issue of all issues with the potential to be most limiting (including cultural issues) is a deficiency of MG. If it isn't, it's an absolute certainty the application of the Epsom salts solution will be a limiting factor. See Liebig's Law of the Minimum for confirmation. AL

To me, it looks like they used self-sticking drywall tape (the stuff where you see the dots) and then coated the walls with a thin layer of textured quickrete. Is the piece that’s broken away very hard if you try to break it?