A photo would really help. Words alone can mean very different things to different folks, But based on the info so far I'd be questioning the magnesium and the azomite additions. Such additions are unusual unless based on a professional soil test and could easily create problems. Dave

Here's the

Are you sure it isn't too wet? I can't see the soil but the plants look pretty sick. Did they go through a cold morning or more? The one leaf looks burned from something - too cold or too hot? Lift the root ball out and see how wet the soil is. If very wet put the root ball on some newspapers to wick away a lot of the water. After a day or more, put it back in the pot if you want it in that pot and that soil. You might be further ahead by pulling out the begonias and check the roots for rot. If not rotted, put them into a smaller pot with fresh potting mix. Do not over-water until they are actively growing again. If rotted you can start some new plants by cutting the cane above the rot and rooting them in water or a good potting mix. DO NOT OVER WATER though.

probably need a pic to tell whats going on ... and more info ... is it potted or in water .. indoors out out.. etc ... ken