Hi Rita, no experience on asthma, but i do have some advice that might help.

Ive always found if you just start one thing at a time you can tell within a few weeks if its harmful or helpful. Over the last few years ive come across a few duds in supplements/herbs that have made things worse.

Asthma is inflammatory, so i dont know what the specific herbs/supplements are to comment, but anything that could be inflammatory should be avoided. Otherwise just steering clear of inflammatory foods should be helpful without herbs depending on what path you take.

Its hard to know what is 'truth' from naturopaths, from my experience they are much like doctors and have set ideas on what works and what doesnt. Do your own research on the individual herbs and make up your own mind if its ok. The other thing that might help is an asthma forum, someone on one of them might have tried some of the herbs your thinking of and have specific experience on results.

Do some research too on the immune system. Its helpful to know how the immune system works and that with asthma its basically the immune system seeing something normally harmless as an invader and mounting a response, too strong a response. Its an error in the immune system, modern medicine sometimes tries to fix errors like this (not usually with asthma but with other autoimmune disorders) with immune suppressors so the response isnt so severe. However boosting the immune system shouldnt cause your body to mount a worse attack when triggered. I would think its safe, i think the fear of immune boosters flaring up conditions like asthma is misguided, and shows a lack of understanding of how the immune system actually works.

I have endometriosis, there are strong theories these days that it is autoimmune, in my experience with it, ive found boosting my immune system essential to my health and improvement of symptoms, it never made my symptoms worse.

Hope that helped and didnt confuse you even more.