Fall blooming chrysanthemums typically flower under natural conditions (grown outside without artificial forcing) around the first week of September through approximately the last week of October. During the last two fall seasons in New Jersey we have seen unusually cold and dry nights (Summer/Fall of 2017) to excessively warm day and night conditions with above average humidity (Summer/Fall 2018). These drastically different weather conditions cause a problem with the chrysanthemums natural flowering response (when the buds open up with colorful flowers). Last year’s garden mum crop opened earlier than we had expected. This 2018 Fall season we are seeing flowering that is as much as 2 weeks later than we expected. While every attempt is made at producing a garden mum that blooms on an exact date, mother nature does not always cooperate and for producers of garden mums this has been a very challenging year. The mums that are planted will flower, but because of how hot and humid it was all the way through October, please expect your mums to be as much as 2 weeks behind last year’s flowering date.
Source: Ball Chrysanthemum Advisory Committee