Hi Lucille, SO sorry to hear about your low temps...hopefully because you covered them with fleece they will be okay. Should know in about 3-5 days, maybe a week...look for some dehydrated leaves or leaves falling off? Hopefully it wasn't 28 degrees for many hours...

I'm surprised your last frost date is middle of Feb. I live in Central FL and my last frost date and the middle of March. I'm in Zone 9b south of Orlando. We occasionally see frost in the middle of March but its quite rare... What is your Zone?

Good luck and please keep us posted...

It was 28 for quite a few hours, so I guess they are toast.

Not all citrus are created equal; and inground trees fare better than in containers. Depends a lot on what variety you have and sometimes on the rootstock. If you are so far off the forecast, perhaps you have a colder microclimate; I would get a minimum/maximum thermometer so you can check for yourself.