half a century, Robert Griesbach, PhD'55, has cultivated his garden,
working to build a better daylily. Griesbach's latest is a deep
purple beauty - named for his U of C mentor.
his five-acre farm, nestled between crops of corn and soybeans
in Delavan, Wisconsin, Robert Griesbach, PhD'55, spends his summers
tending to more than 10,000 daylily plants that form a tightly
packed field awash in hues ranging from pink and red to yellow
and near white. Yet every year or so, he disrupts this tranquil
scene by digging up and transplanting a few choice blooms, before
applying herbicide to kill off the remaining thousands. The next
year, he starts the process over by replanting the field with
seeds produced from hand pollination.
The ritual is part of Griesbach's six-decade pursuit
of new daylily varieties. To date, he has introduced some 60 new
daylily plants through a number of nurseries, including Klehm's
Song Sparrow Perennial Farm in Avalon, Wisconsin, and Wayside
Gardens in South Carolina. A professor of biological sciences
at DePaul University for 34 years, Griesbach developed a new method
for doubling the chromosomes in daylilies-with four sets of chromosomes,
tetraploids offer more color possibilities. His latest creation
is a deep, velvety purple daylily to be named in memory of his
mentor at the University of Chicago, botanist Paul Voth, SM'30,
Griesbach's father, a church organist and choir
director, grew irises and other flowers on their city lot in Menasha,
Wisconsin. Though always interested in plants from working with
his father, Griesbach's interest in daylilies blossomed upon coming
to the University and doing graduate work under Voth. A 1940 Quantrell
winner who himself had studied under U of C botanist and daylily
breeder Ezra Kraus, PhD'17, Voth suggested that Griesbach study
daylily dormancy and germination to arrive at a more exact reading
of the effect of cold temperatures on deciduous daylilies.
prompted breeder Robert Griesbach's interest in daylilies
was, he explains, the realization that "daylilies were going
to become the most important garden perennial."
Voth was a dedicated mentor, hand-pollinating daylilies
to produce the seeds Griesbach used in his experiments. Unlike
evergreen daylilies, which keep their foliage year round and grow
well in the southern United States, deciduous daylilies lose their
foliage in the fall and are more common in the northern United
States. Griesbach found that deciduous daylily seeds must be in
the ground at a near-freezing temperature for six to eight weeks
before they start to develop; they can still germinate after being
exposed to slightly warmer conditions, but must remain at those
conditions for a longer period of time. His findings helped give
evidence to what had previously only been noted anecdotically.
After completing his graduate work in botany at
Chicago, Griesbach returned to teach at DePaul-where he had earned
his bachelor's and master's degrees-in its biological-sciences
department, eventually chairing the department for 14 years. At
DePaul, he was able to blend his scientific work in cytology and
the genetics of polyploidy (plants with more than the normal number
of chromosomes) with what quickly became a lifetime interest in
breeding daylilies. "My research and my hobby were all combined,"
he says. "I continued school, so to speak, on Saturdays and Sundays."
What prompted his interest in breeding daylilies,
he explains, was the realization that "daylilies were going to
become the most important garden perennial." It's a strong statement
from a generally mild-mannered professor, but he saw plenty of
evidence to back his argument: Daylilies can flourish in a variety
of soils, temperatures, and light intensities. They also have
a long growing season, from late spring to autumn; every day brings
a new group of blossoms; and, in the northern United States, they
can be grown without being mulched. But perhaps their greatest
feature is being extremely resistant to fungal and viral diseases.
Today, Griesbach's confidence has proven well-placed: The American
Hemerocallis Society boasts over 10,000 members, publishes the
quarterly Daylily Journal, and hosts regional and national conventions
and growers' competitions.
Griesbach began his breeding experiments by working
to develop tetraploid daylilies, which have four sets of chromosomes
instead of the two sets common in many plants. In increasing the
number of chromosomes, his goal was to deepen the daylily gene
pool and thus expand the possible variations of color and other
physical attributes. Taking the seedlings left over from his dissertation
experiments, he treated them with the chemical colchicine, which
caused their cells to begin to divide-creating a duplicate copy
of the chromosomes-without completing the cell-division process.
This plant was left with cells with the genetic material for two
Two years after his tetraploid first bloomed in
1959, Griesbach formally introduced the new flower. Crestwood
Evening, which he had collaborated on with breeder Orville Fay,
made its debut at the 1961 National Daylily Convention in Chicago.
The new tetraploids were noticeably different from
their diploid ancestors. With twice as many chromosomes, cell
nuclei were larger. With larger cells, the tetraploids had larger
flowers, leaves, and roots. An increased root system meant that
the tetraploids could absorb more water and nutrients, and thus
grew more vigorously. Doubling the chromosome number also meant
that the tetraploids' color could be more intense, because the
new plants could have as many as four doses of a given pigment,
while diploids could only range from zero to two doses.
Not all of the results were desirable. The new plants
were stiff and sometimes brittle. And, because they were temperature
sensitive, the first generation of tetraploids was not very fertile:
if the temperature exceeded 80° F, pollination would most likely
not take. But Griesbach eventually found that such undesirable
qualities could be bred out of the daylilies in second, third,
and fourth generations.
Asked to name some of his favorite creations, Griesbach
thinks over his answer carefully. Ruby Throat, Towee, Baltimore
Oriole, Painted Trillium, and Blazing Sun win the honors. "One
of my interests was to work on certain colors that, at the tetraploid
level, were not very well established, and red was one of them,"
he explains. Ruby Throat and Towee, for example, offered a clearer,
less muddy red than previously available. Although he has worked
on many colors to improve their clarity (how pure a color is),
saturation, and intensity, Griesbach admits that all his favorites
fall in the reds and purples.
Retiring in 1989, Griesbach moved to Wisconsin with
his wife, Mary Lou, in 1991. The relocation took two years because
he had to transfer two crops of flowers-daylilies and lilies.
In the end, Griesbach transplanted several thousand plants from
his home in Park Ridge, Illinois, to his new farm in Delavan,
Wisconsin. His summer 2000 crop now includes 3,000 daylilies blooming
for the first time this year and representing 150 different parents.
Of these 3,000, only three to four will be improved enough for
possible naming and introduction; those improved but not significantly
improved enough for introduction will be used for crosses to produce
seeds. The hope is that with each generation, the resulting plants
will become more and more improved in terms of the particular
trait for which Griesbach is breeding them.
Among the flowers growing in his field are several
plants of the Dr. Paul Voth daylily, to be registered with the
American Hemerocallis Society this summer. Griesbach plans to
introduce the flower to the public in 2001, which will be sold
through Klehm's. Griesbach chose to name this deep, velvety purple
daylily after Voth both because, as daylily hues go, it's one
of the more "manly" hues, and because it's in Griesbach's own
favorite color range. "Dr. Voth was the one who really got me
interested and involved with daylilies in the first place," says
Griesbach. "I learned so much from him about daylilies, I just
feel that it's very appropriate to honor him in this way."