Mum’s the word! How we create our Fall Outdoor Cascading Chrysanthemums

Mum’s the word in November at Bellingrath, when the Horticulture Staff sets out one of our signature events, the Fall Outdoor Cascading Chrysanthemums display.

The chrysanthemums show is the culmination of a year’s worth of meticulous greenhouse work. The plants are continually shaped and trained over many months in order to create the most eye-catching cascades of blooms in time for fall.

The process begins when the Horticulture Staff creates a plan for the number of hanging cascades, columns, spheres, and hanging baskets, and the colors or varieties for each area.

Each year, the staff increases the chrysanthemum cuttings by 5 to 10 percent, because not all of the plants will be top quality, and only the best will do for the display. When cuttings are taken in January, the plants aren’t blooming yet, and it takes an expert to differentiate among the 13 varieties of chrysanthemums in the greenhouse, based on their leaves alone.

After about a month in the propagation greenhouse, the cuttings are transplanted into 2-quart pots and moved into the production greenhouses. Cascade chrysanthemums are vigorous, and can grow about a foot in about a month. In March, the cuttings are tied to upright bamboo stakes so that they can continue in a straight pattern.

At this time, the mums also begin to grow side branches, and it’s time to pinch the plants, a labor-intensive process in which the growth past the first pair of leaves on each side branch is removed to encourage more branching. The pinching signals the plant to produce more side branches, and, eventually, more blooms. About three weeks after the first pinch, the plant will be ready for the next, and the process continues through the end of May. (However, the top, or terminal bud, is not pinched.)

The day length that the plants receive is manipulated from January through May. Mums are “short-day” or long-night bloomers, like poinsettias. If they were allowed only to receive the natural day length, they might begin to bloom. Here on the Gulf Coast, that would mean the plants could bloom from January to May. In order to rein in the blooming until November, the growers use nighttime interruption lighting in the greenhouses from 10 p.m. to 2 a.m. each night.

The growers must check the lights several times each week and communicate with the nighttime security guard to ensure that the lights come on each night, because just three long nights of darkness would allow the plants to set flower buds and bloom too early for the November display.  In addition, the stock plants at Bellingrath are never allowed to bloom and are kept under nighttime interruption lighting all year.

Beginning in mid-May, the summer nights are short enough that the outdoor mums won’t initiate their blooms until about the first of September, when all pinching and shearing of the plants will stop. In mid-September, when the plants reach the right length, the growers spray growth regulator applications on the plants to put the brakes on their vigorous growth.

At the beginning of June, when the chrysanthemum plants have grown 4 to 5 feet tall, the growers move the plants outside, then use them to create cascades, columns and hanging baskets. Also, cultivation continues on the plants that were trained to be traditional “garden mums” to be used in the flower beds.

In early to mid-October, the process of relocating the Cascading Mums to the Gardens begins. Finally, at the beginning of November, the mums’ colors reach their peak.

The design of the Cascading Mums display creates a lovely effect when the cascades of blooms are met by identical potted mums of the same variety, which leads to a uniform display of color from the balconies to the ground.

The 2015 Fall Cascading Chrysanthemums display will have 370 cascading mums, created from about 400 in production; 130 columns of different sizes; and 40 hanging baskets, in addition to the regular bedding plants. Don’t miss out on this amazing feat of horticulture and engineering at Bellingrath Gardens and Home.