Aller-Calm is primarily for hayfever and other environmental allergies.  It can be used as a preventative or used when acute with allergy symptoms.  Asthma is a form of an allergy too.  

Preventative: Begin using 2-4 weeks before the onset of the allergy season by taking Aller-Calm two times per day.  
This will increase resistance to pollens before they even start.  keep taking throughout the allergy season.  Results can vary from a percentage decrease in reactivity to complete eradication of symptoms.  Taking small amounts of local bee pollen and avoiding dairy consumption at this time will help.  Since most allergies are a symptom of liver deficiency, also taking Liver Detox may help.  

Acute Allergies:  The dosage here needs to be from 3-4 times per day until symptoms begin to subside.  
Stopping an acute allergy attack with herbs is more difficult, but is still possible.  Avoid dairy, dusty environments and flour products.  

Eyebright, Nettle and Ambrosia (also known as ragweed... this leaf extract inhibits histamines caused by the pollen of this plant) are anti-histamine in action.  Yerba Santa helps decongestant and Lobelia relaxes the chest, intercostal muscles and diaphragm.  

By treating the underlying constitutional predisposition, Aller-Calm can work deeper.  Aller-Calm may support asthmatics as well, which is an allergy response.
- vitality works herbal handbook