Gardeners in such states as Minnesota, North Dakota, South Dakota, and one or two of their near neighbors formerly had difficulty in planning their gardens, so they were full of bloom in the late Summer and early Fall months.
The fact impressed me during a trip to the East in late Summer a little over a dozen years ago. I was in Boston about Labor Day and was impressed by the abundance of bloom in the flower gardens.
When I returned to the Twin Cities, I noted how bare of blooms our gardens were in Minnesota. That gave me the idea that something could be used to give abundant bloom in late Summer, and garden chrysanthemums seemed one good possibility.
Up to that time, not many varieties of mums would regularly bloom in the Fall before frost killed the flowers in Minnesota.
That was because chrysanthemums were short-day plants: that is, they usually waited till the days were much shorter than they were in mid-June before they would set buds, and the farther North one went, the later they were in bloom, and the earlier the killing frost might come.
To overcome the late-blooming, finding some that bloomed a little earlier and, by crossing and selecting, obtaining an early-flowering race of garden chrysanthemums would be necessary.
Efforts in Breeding and Selection
The first materials we used were several strains that had been brought together by F. L. Mulford in Washington, D.C.
We obtained several United States Department of Agriculture strains and varieties from the Horticultural Field Station at Cheyenne, Wyoming, and grew them at Minnesota’s University Farm.
Some of these were early enough to bloom before hard frost, but most were too late for good blooming.
So we obtained open-pollinated seeds from some of these, crossed them with each other, and obtained some earlier than their parents – often with better flowers.
Also, some greenhouse types (essentially the same as most outdoor mums) were crossed with the earliest outdoor ones.
Some of our varieties came from these crosses in later years. In 1941, we named and introduced five varieties.
Two of these have proved to be among our hardiest ones: Duluth and Welcome.
Early-Blooming and Hardy Varieties
Not much attention was paid to hardiness in those first varieties; anything that would give fairly good bloom was enough. Even yet, few chrysanthemums are fully hardy in Minnesota and similar climates.
Clara Curtis is one such hardy chrysanthemum, but it belongs to another species – Chrysanthemum rubellum. Various varieties, subspecies, and species have been crossed with these early chrysanthemums to obtain hardiness.
The variety Astrid, a derivative of Chrysanthemum arcticum, has been used by others as well as by us in Minnesota.
Although we obtained a little greater hardiness, never have we obtained any variety that consistently bloomed before hard frosts from this strain.
Lately, we have been using Deanna Durbin, a variety derived from Chrysanthemum zawadskii, and hope to obtain good flowers that are early enough and a fully hardy plant.
Deanna Durbin blooms a little the first year, but it seems to have more hardiness than most varieties.
From this material, we hope to obtain hardy varieties that will bear satisfactory flowers. Already, some have appeared that are good but are not yet fully tested for hardiness.
Notable Breeders and Their Contributions
Three men, in addition to Mulford, who have produced many varieties to fit many conditions are Cumming, Kraus, and De Petris.
Several others are working on various phases of garden chrysanthemum breeding and are now beginning to produce new varieties.
For example, Lehman, a nurseryman, is breeding for special characters. In New Hampshire and Nebraska, there is important work being done, and in the U.S.D.A., Horticultural Field Station work with mums is still progressing.
Uses of Garden Chrysanthemums
Garden chrysanthemums have various uses, depending on their type. For example, the cushion type is specially adapted to mass use for their landscape value.
Several of the Minnesota varieties are of this type, such as Harmony, Redwing, Aurora, and Brilliant.
Some new ones with better colors of this type will be introduced from Minnesota in the next year or two.
Types and Characteristics of Garden Chrysanthemums
The type I like best is the type that grows taller with longer stems for cutting. Incidentally, from the Zawadski material, there will soon come some tall and upright varieties suitable for growing in the cutting garden, producing long sprays of good flowers. A tall double white of this sort should be introduced soon.
Then, an intermediate type grows less tall and is spreading but not compact like the cushion type.
In this group are such varieties as Zantha, our Maroon ‘n Gold, and Violet. These are good for cutting and making a mass display in the garden.
The variety Violet illustrates the value of hardiness in that it produces a taller, more upright plant when two years old than when a first-year plant from cuttings.
The so-called English chrysanthemums are interesting because of their sturdy growth and larger flowers. Most are too late for Minnesota conditions, but a few produce some bloom, such as Indiana and Gold Standard.
One cross between our Maroon n’ Gold and the English variety Westbourne has sturdiness, large flowers, and brilliant color. This cross will probably produce a better variety of this type.
Soil Drainage For Winter Survival
Speaking of hardiness, the most important factor in the environment is the matter of soil drainage.
The better drained the soil, the better the chance the plants have of wintering well. That is why mums planted near the house usually come through the Winter in good condition.
Protecting Mums From Frost
All in all, garden chrysanthemums have proved all that could be hoped for to fill out our northern gardens in the late summer and early fall months.
If possible, plant them where they will be protected from the first Fall frosts, or protect them by covering them with paper or muslin when frost threatens.
44659 by Dr. Lewis E. Longley