Plant of the Week
Celestial™ Dogwoods
Latin: Cornus x ‘Stellar® Series’
 Now that I’m a grandparent, I hear lots of comments about who the babies
look like. Perhaps hampered by poor imagination or even poor eyesight, I don’t
always see the described resemblance, but it seems to be a grandparent’s calling
in life to agree with all such proclamations.
When it comes to plants, I’m able to pick up on family resemblances a little
more easily. One of the easiest to see is the dogwood hybrids developed between
the Kousa Dogwood and our native Flowering Dogwood.
These spring flowering hybrids are a result of crosses made in the mid-1960's
by Rutgers University plant breeder, Dr. Elwin Orton. So far, six trees have
been released from the program, and most show more resemblance to momma,
Cornus kousa, than the male parent C. florida.
The Celestial Dogwood, when 19 years old, was 17 feet tall and 14 feet wide
with a distinctively vase-shaped habit of growth. With age, it will become more
rounded in overall habit.
The white flowers, actually modified leaves called bracts, are tinged with
green in the beginning and have the familiar overall shape of a dogwood bloom.
But they show characteristics intermediate between the two parents. Instead of
the sharp-pointed tip of the Chinese Dogwood, the blooms of Celestial Dogwood
are rounded with only a slight point at the tip, but they lack the familiar
notch of the Flowering Dogwood.
Bloom time is after the leaves appear and usually commences after the first
week of May, about 3 weeks later than the native species blooms.
Orton, one of the few publicly supported ornamental plant breeders in the US,
began his breeding program trying to increase the vigor of the dogwood to make
it less susceptible to dogwood borer. This insect is capable of killing young,
newly transplanted trees or older trees that have gone into a growth slump with
age. His hybrids show increased vigor and are much more resistant to the pest
than the native dogwood.
As a lucky happenstance, his dogwoods began to be released about the time
that dogwood anthracnose (Discula) began killing older dogwoods up and
down the East Coast. While not completely immune to the disease, the increased
vigor of the hybrids makes them highly resistant under normal garden
circumstances.
Celestial dogwood and its siblings have a longer pedigree than dogs shown in
a New York Kennel Club competition. In the new world order where universities
seek cash to support ongoing programs, a number of legalistic approaches are
used to protect their property. First, the plant is patented (PI 7204) with the
official cultivar name of "Rutdan," a name never used in any public forum
discussing the plant.
Plant patents expire after 20 years. That’s often how long it takes for a new
plant to be noticed in the nursery trade, so the university also trademarked the
name Celestial, which can be renewed indefinitely. Originally they tried to
trademark this plant as "Galaxy," but people at Rutgers must not drive Fords
because Ford Motor Company has this name locked up.
Propagation agreements must be signed with the university to propagate the
plant, even after the patent expires, and use the name Celestial.
From a cultural standpoint, the Celestial dogwood is grown similar to our
native dogwood, but its hybrid vigor makes it less finicky about some of the
cultural details. It’s best suited for planting in an area that has well drained
soil and receives shade after 3 pm.
Like with all dogwoods, you want to make sure the plants are kept watered
during droughts. But don’t overwater. The plant is ideally suited for use as a
small specimen tree in the landscape, as a doorway planting near the entrance or
near the patio where its blooms can be enjoyed in May.
By: Gerald Klingaman, retired
Extension Horticulturist
- Ornamentals
Extension News -
March 2, 2001
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