Mums offer antidote to colorless fall gardens

Joel Baer and Taylor Highfill, freshmen at Northeast Vernon County, sort through boxes of chrysanthemums. The Northeast Vernon County FFA chapter sold 700 chrysanthemums during their annual fall fundraiser. Submitted photo.

Flower beds and porch fronts need not languish as summer flowers succumb to fall's cold touch.

Chrysanthemums offer a burst of color for those who want to liven up their yard.

"Now is the time many summer annuals are looking weather-worn," said David Trinklein, University of Missouri Extension state horticulturist. "Chrysanthemums offer garden enjoyment well into fall because of their ability to tolerate light frosts."

"Chrysanthemum" comes from Greek and means "golden flower."

A type of daisy, these plants range in color from reds and yellows to purples and whites, They often are called "hardy mums," but the term is a misnomer in northern Missouri.

"In parts of the Midwest, we are coaxing them a little farther north than they are happy," Trinklein said. "To help ensure survival, plant mums in a somewhat protected spot with a little shelter that still gets adequate sun during the growing year. Also, cover those mums with a bit of straw or leaf mulch to give it extra winter protection in their first winter."

Growers should remove that protection when spring arrives and the plants rejuvenate. Mum foliage grows most of the year, but blooms typically form in late summer and early fall, when they begin to receive about 10 hours of darkness each night.

"They are photoperiodic plants that bloom in response to the length of day versus the length of night, and it takes a shorter day and longer night to induce it to bloom," he said. "In a year like this one, mums can suffer from heat delay, where warm temperatures hinder blooming even after nights are normally long enough."

This phenomenon will delay blooming until later in the fall.

Left to their own devices, mums can reach up to 3 feet in height. Mums need a bit of special care during the growing season to produce an attractive show of color in the fall. After the plant emerges and reaches a height of 5-8 inches in spring, pinch off the tips every few weeks until about July 4.

"By pinching a hardy mum back, growers both reduce size and cause basal branching to create a more cushiony, moundlike plant with a greater numbers of blooms," Trinklein said.