When the plants do not get enough water, they can wilt, develop yellow leaves and drop flower buds.

When the plants get too much water, the plant gets a sickly look too and can drop flower buds.

Some cultivars of hibiscus (usually the double-flowered ones) begin to drop buds when daytime highs stay consistently in the 90s (like has recently happened here in Texas). As the weather begins to cool down in late September and October, plants dropping buds due to the heat will begin to hold onto their buds and bloom.

Aphids are small (but visible) sucking insects that will cluster on the new growth and buds and cause problems for some flower buds. They can be controlled with most general-purpose insecticides

The hibiscus bud midge or the gall midge larvae feed inside the flower buds, causing them to drop. Because they are hidden in the buds, they are difficult to see and control. You have to cut open several fallen buds to see. The larvae of the gall midge are tiny and look like little maggots, so open a few and look very carefully. Systemic insecticides should control these pests. Imidacloprid is a good insecticide for this problem. But if you do not see any midge larva, the problem is more likely due to environmental conditions.

that is not a bud its a potential seed pod. after the flower if the hibiscus was pollinated then teh ovary swells up and will produce seeds. Many varieties also produce false seed pods. If you know for sure than that flower was NOT pollinated, then remove it. but IF it may have been pollinated and you want seeds - then leave it alone and wait for about 6 weeks. once it ripens it will crack open along the seams and dry out. If there are seeds they should be a decent size, black and fuzzy. maybe 3/4 or 1/2 the size of a popcorn kernel.

Thanks Merkity! Yeah I wound up cutting some off and cutting a few open. I saw rows of tiny seeds so I figured they may have been developing seed pods. I don’t plan on propagating any more so I just cut the rest of so it’ll grow some more flower buds.