Well, you won't like my answer much, but I would start over with a new plant if one was available, but I know satsukis aren't always easy to find. For one thing, you should have either kept it inside in a very cool (just around 40 F.) place for winter, and watered only when the top of the soil was dry, plus forget about misting, OR theoretically left it outside with protection, but Colo. is really too cold for it. That's the trouble with azaleas - they need a cool place to go dormant, but Satsuki especially can only take so much cold, but moving it back and forth is not a good idea. It may have become too cold on any given day or night, or having possibly gone dormant prior to your getting it, found every day water (in water hogging peat they're usually planted in) was too much to deal with, even though azaleas normally can take plenty. It's hard to say now, plus whatever the bugs are, they could well have helped out in causing trouble. To get rid of them, I would submerge the whole thing in the sink for up to 20 mins. at least, then let it drain and apply Safer's Soap spray (rather than your homemade version) to the foliage, and a mild houseplant fungicide to the soil.. But it's hard to predict the future as black leaves usually means roots have begun to rot or have gotten too cold.

Hi Lucy,

Thanks for your reply. I was really hoping to learn from your expertise in bonsai art after reading your other replies to fellow bonsai enthusiasts.
After reading your mail, I simply refused to give up the Satsuki azalea. I bought some new soil (for tropical bonsai), rapeseed cake organic fertilizer, and Schultz insect spray from the Bonsai Boy.com. I have since then placed the satsuki azalea outdoor as the Spring is finally here in CO. I put a layer of new soil on top and water the bonsai regularly. The bonsai seems to spring back to life, as I can see new shoots and leaves are coming out of those previously broken branches. I have also not seen any bugs after using the insect spray. However, most leaves still looks dried and blacken to some extent. Some even curled up which I don't know why. Maybe you can help explain this to me?
Also, I bought a Dwarf Jade bonsai recently from the same online company, I found some little bugs resembling tiny flies after 2 days the bonsai arrived. I wonder if the bonsai is already infected with bugs before it was sent to me. Nonetheless, I quickly sprayed some Schultz insect spray on the Dwarf Jade. It doesnÂt seem to eradicate the bugs totally and the leaves are starting to fall off (eventhough the leaves still look nice and not dried). I water the plant 3 days once as according to the instruction sheet. Please let me know what you think of this situation I am having now. Thank you very, very much for your time.

You didn't do the fungicide thing, and that's why you're getting black leaves - some roots are rotten. Do it, forget the bugs for now, and see what happens - just follow the label info. (for house plants though, not garden, or 'trees' etc.