Chrysanthemums – A Fall Classic

Chrysanthemum morifolium, more commonly known as Chrysanthemums, or Mums, are a classic fall planting in landscapes and gardens all over the world. They were first grown as a flowering herb as early as the 15th century BC in China, brought to Japan in the 8th century, and introduced to Europe in the 17th century.

Although most often used as an annual planting, or placed in pots along walkways, they are actually a hardy perennial that is easy to grow and which will return more beautifully each year. Chrysanthemums are adapted to Plant Hardiness Zones 5-9. They can be grown in a variety of soil types, as long as it is well drained. They require full sun, and in colder climates must be protected in the winter. At maturity they reach heights of anywhere from 12 to 36 inches.

Planting and Care
Plant containerized Chrysanthemums anytime during the spring, summer, or early fall. The earlier they are planted, the better developed their root system will be come winter. When planting, incorporate 2 – 4” of peat moss or compost into the soil and space them 18 – 24” apart to allow adequate air circulation. Water them regularly in the summer to a depth of 6 – 8” and mulch. Apply a complete fertilizer such as 5-10-10 or 5-10-5 in the spring and again in August.

Flower Fact
A Chrysanthemum bloom, which appears to be a single flower, is actually composed of hundreds of smaller flowers called florets. Each one of these florets is capable of producing a seed, similar to its plant relative, the Sunflower. The National Chrysanthemum Society, Inc., USA divides Chrysanthemums into 13 classes based primarily on its bloom form.

[ Class 1 Irregular Incurve ]
The largest blooms of the chrysanthemum genus. Characterized by loose, incurve florets with fully closed centers. Florets on towards the bottom of the bloom sometimes droop downwards to give a skirted effect.
[ Class 2 Reflex ]
Characterized by florets that overlap and curve downward, having the appearance of bird plumage.
Photo by Union County College
Photo by Union County College
[ Class 3 Regular Incurve ]
Characterized by a globular bloom, with florets which smoothly incurve and form a ball.
Photo by Union County College
Photo by Union County College
[ Class 4 Decorative ]
Characterized by a more flattened bloom with short petals. As in classes 1-3 the center disk should not be visible. The upper florets tend to incurve, but the lower petals generally reflex.
Photo by University of Minnesota Extension
Photo by University of Minnesota Extension
[ Class 5 Intermediate Incurve ]
This bloom class is smaller than the irregular incurve, with shorter florets, only partially incurving with full centers, but giving a more open appearance. Many of the popular commercial incurving types are in this intermediate class.
Sten Porse
Sten Porse
[ Class 6 Pompon ]
A small globular bloom, somewhat flat when young but fully round when mature. Size ranges from small button types to large disbudded blooms almost 4 inches in diameter. The florets incurve or reflex in a regular manner and fully conceal the center.
[ Class 7 Single and Semi-Double ]
A daisy-like flower with a center disk and one or more rows of ray florets.
Photo by KENPEI
Photo by KENPEI
[ Class 8 Anemone ]
These blooms are similar to the semi-doubles, but have a raised cushion-like center.
Photo by  Abhishek Mishra
Photo by Abhishek Mishra
[ Class 9 Spoon ]
Essentially the same as the semi-double, except the ray florets are like spoons at the tips. The center disk is round and visible.
[ Class 10 Quill ]
The florets in this Class are straight and tubular with open tips. The bloom is fully double with no open center.
Photo taken by Fanghong
Photo by Fanghong
Class 11 Spider -
Characterized by long tubular ray florets, fine to course in nature, that sometimes form coils, or hooks on their ends.
Photo by  Juni
Photo by Juni
[ Class 12 Brush or Thistle ]
Fine tubular florets which grow parallel to the stem and resemble an artist's paint brushes or in the thistle form the florets are flattened, twisted and dropping.
[ Class 13 Unclassified ]
Those blooms which fit in none of the other classes. They are often exotic, with twisted florets. They may also exhibit characteristics of more than one bloom class.

Interesting Use
One of the most important commercial uses of the Chrysanthemum is for the production of the organic insecticide Pyrethrum. The flowers are crushed, and the active component contained in the seed case is extracted. Pyrethrum is one of the most effective, yet least toxic insecticides with a Lethal Dosage (LD50) Value of > 18,000.

With it’s myriad of shapes, colors, and textures, Chrysanthemums can make a dramatic impact in your garden or landscape not only this fall, but for many years to come. Try some out this season.