Depending on the month, I can usually predict calls and email questions. This was the #1 October question last year.
Why don’t the mums I bought at the grocery store last as long as yours?
The answer could be as simple as care & feeding or that many grocery stores and big boxes purchase their mums from mega growers who only grow mums in greenhouses.
Our mums are grown locally outdoors so they acclimate better to our climate. Greenhouse grown mums have a much harder time getting used to the outside climate which can lead to a shorter bloom time.