Hibiscus flowering issues

Hi,
I live at the coast in northeast Florida and I have about a half dozen hibiscus in my yard in full sun. One or two of these plants/small trees will bloom in the spring before it gets too hot out and they never bloom again until next spring. Every time I would give them water the leaves would turn yellow so I stopped watering them. I read everywhere how easy hibiscus are to grow and I'm about ready to get rid of mine and try something else that will actually grow. Recently we've had a LOT of rain so just about everyday I have to remove yellow leaves. I have a larger hibiscus 'tree' in the shady part of my yard which rarely blooms but it grows better than the ones in full sun.
I fertilize them once or twice a year.
Does anyone have any idea what I could be doing wrong ?
Thanks.

Maybe getting too much water, or rather the soil around them staying drenched? Dig around a bit and see if that is the case and, if so, you'll need to amend the soil with sand most likely. They might also need to be fed more in the summer for more blooms. Either a 20-20-20 or plant food with high middle number like BloomBurst. Your fellow Florida gardeners should be able to help also.

Hibiscus are unusual, they are happier if they don't have a lot of phosphorus, so unlike other plants, using bloom booster fertilizers or anything in general with a high middle number could actually be part of the problem. As an example, one of the mail order hibiscus places that I get my plants from sells a hibiscus fertilizer that is 17-5-24. You don't necessarily have to use exactly that ratio, but that gives you an idea how much phosphorus they should be getting relative to nitrogen & potassium.

The other thing I would check on is your watering--hibiscus don't like to be soaking wet, but they also don't like to dry out, and inconsistent watering (letting them get bone dry and then drowning them) will stress them and they won't bloom as well. It'll also cause them to have more yellowing leaves than they would if you kept a more consistent moisture level.

Especially because you noticed that they are blooming better for you in the cooler weather, you might also consider giving them a little bit more shade--they definitely like sun, but they don't need it beating down on them all day especially if they're in containers. They would probably be happier with a bit of PM shade in the summer and also this may help you keep your watering more consistent since they won't dry out as fast. I keep all mine in an area where they get lots of sun in the AM but are in shade for most of the afternoon and they bloom just fine.

Thanks for your suggestions. I'll give them a try.
These hibiscus are just so puzzling to me. Most people say they're easy to grow, will grow in most any soil, and don't need excess watering. I've been thinking that maybe mine are getting too much direct sun, even though they're a tropical plant so I'll try relocating them to a not quite so sunny spot. Thanks again.

Most plants need more TLC if they're in a container instead of the ground. Containers dry out a lot faster than the ground does and the more sun you have them in the faster they're going to dry out. Most of my hibiscus pots need to be watered every other day when our temps are in the mid to high 80's and every day when it gets over the mid 90's. If they were in the ground I'm sure they could go longer between waterings. Hibiscus really aren't hard once you have them in the right conditions--I think if you get them a little more shade and water them consistently they'll do fine.