Q.Why did my fall mums turn brown and quit flowering?
I purchased large, beautiful mums in August and now they quit flowering and the new buds are turning brown before they open.
The mums that are often sold in autumn and are covered in blooms are highly cultivated and forced into that abnormal bloom. It seems to leave the plant exhausted. In addition, these mums are often not hardy. They are treated as annuals and tossed onto the compost pile when their glory fades. Try dead-heading and fertilizing to coax more blooms. If you have planted it, put 3-4 inches of wood mulch over the crown once the ground freezes. If still in a container, try over-wintering in a garage. Don't let it dry out as this kills the plant for sure. A gentle watering on Thanksgiving, New Year's, Valentine's Day and Easter should be sufficient. The link that follows goes to an article on container mums. https://www.gardeningknowhow.com/ornamental/flowers/chrysanthemum/growing-mums-in-containers.htm
