Tuesday, October 27, 2009

Landscape and Nursery - Some Cypress and Falsecypress Species for Delaware

The following are some cypress and falsecypress species that are adapted to Delaware landscapes. Note that the genus Cupressus has been changed for some species to Callitropis. One particularly interesting species is Arizona cypress which deserves wider planting in Delaware as a substitute for Leyland cypress.

Nootka falsecypress (Callitropis nootkatensis) ‘Pendula’, ‘Green Arrow’, ‘Van der Acker’
Arizona cypress (Callitropis glabra) ‘Silver Smoke’
Arizona cypress (Callitropis glabra) ‘Blue Ice’
Japanese falsecypress (Chamaecyparis pisifera) ‘Boulevard’
Japanese falssecypress (Chamaecyparis pisifera) ‘Curly Tops’
Hinoki falsecypress (Chamaecyparis obtusa)

A high priority is to identify alternatives to the overused and problem-susceptible leyland cypress (X Cupressocyparis leylandii). One good example of an alternative to this screen plant is the Arizona cypress (Cupressus arizonica).

There is a debate on the proper nomenclature for this group of plants. This is a botanical lumper-splitter type of project. Some experts separate C. arizonica from C. glabra. Other experts lump them and place glabra as a variety of C. arizonica. The distinction is not as important, however, as the potential this group offers for Delaware gardens.

There are several reasons why this needle evergreen deserves more attention. First of all, the various cultivars all have an eye-catching silver-blue/powder blue color. The blue hue is even better than what you get with the blue atlas cedar (Cedrus atlantica ‘Glauca’). I love the cultivar names: ‘Blue Ice,’ ‘Blue Pyramid,’ ‘Carolina Sapphire,’ and ‘Silver Smoke.’

The second reason to admire this plant is for its rapid growth. For this reason it is grown frequently as a Christmas tree in the Southeast. So far the plant is also quite free of insect and disease problems. I have not observed bagworms, rust, or cankers like some other evergreen options.

The growth habit on young plants is very similar to our native Eastern red cedar (Juniperus virginiana). Because needles are not born in flat sprays like leyland cypress, the overall texture is very soft. Plants are pyramidal in shape and clearly taller than they are wide. As the plant matures it will open up. Very old specimens almost have a weeping, graceful appearance. ‘Blue Ice’ and ‘Blue Pyramid’ may have a much tighter pyramidal habit than ‘Carolina Sapphire.’

Arizona cypress thrives on full sun exposure. The fabulous blue needle color will probably be diminished in more shade. While constant moisture might promote growth, an established plant should tolerate fairly dry conditions.

Need a cute fact for the next garden party? Arizona cypress is closely related to the artistic and beautiful Monterey cypress (C. macrocarpa) found along the California coast. Unlike its cousin, the Monterey cypress does not seem to like the heat and humidity this area of the U.S. Another garden party trivia note: Monterey cypress is one of the parents of the intergeneric hybrid leyland cypress.

Common Name: Arizona Cypress
Varieties to look for: ‘Blue Ice,’ ‘Blue Pyramid,’ ‘Carolina Sapphire,’ ‘Silver Smoke’
Flower Color: none
Blooming period:
Perennial or annual: needle evergreen
Size: 45’ tall by 20’ wide
Exposure: sun to partial shade
Soil: tolerant
Watering: moist best
When to prune: not required
Suggested use: screen/hedge, specimen

Information on Arizona Cypress adapted for Delaware from "Arizona Cypress – Cupressus arizonica Shrub Profile" By: James Robbins, University of Arkansas. Photo also from that publication. http://www.aragriculture.org/horticulture/ornamentals/plant_database/shrubs/profiles/arizona_cypress.pdf

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