I had very bad asthma a few years back. Every six months or so my doctor would give me stronger medication until I got to the steroids. Then I did some online research and found that local honey sometimes works. I tried it and it took about 7 months but my asthma symptoms diminished to almost non-existent. And a side benefit is that my allergy symptoms vanished as well. Being athmatic is like being an alcoholic, you are always potentially asthmatic so you have to safe guard your self from potential triggers.
The honey you buy in the supermarket will not work because it is pasteurized killing all of the benefits and is basically just sugar. Find a beekeeper in your area that sells honey and give it a try.
lavender oil , its cheap to buy , drop a ( very little) ammount on your bed pillow.
do the same with sofa cushions so when you are in your sitting room you breathe it in.
it comes off easily in a hot wash dont worry ,i do it alltime since me and my nephew have asthma, it doesnt do miracles BUT it does help.
I do exercise to stay on top of my asthma. You don't have to go all out exercising to stay on top of your asthma you could just walk to work or cycle places. It really helps I haven't taken my inhaler in years.