After a severe winter and the third cool, wet spring in a row, many home gardeners know firsthand the problems associated with growing many species of evergreens.
In an earlier newsletter this spring, junipers were on the list of evergreens experiencing problems with diseases. One of the main ways to avoid disease problems is to plant disease resistent varieties when available.
For resistance to Kabatina Blight select the varieties:
- 'Emerald Sentinel'
- 'Manhattan Blue'
- 'Blue Fountain'
- 'Robusta Green'
- 'Columnaris hetzii'
- 'Winter Green'
- 'Silver Globe'
Varieties resistant to Phomopsis tip blight include:
- 'Prostrata aurea var. Saxatilis'
- 'Knap Hill'
- 'Silver King'
- 'Fargesii Prostrata'
Arborvitae suffered considerable winter injury this year. Numerous varieties of arborvitae are available through nurseries and garden centers. Unfortunately, many varieties do not hold up well in our winters. The most reliable variety for Iowa is 'Techny'. It is also known as 'Mission'. This variety has a pyramidal form and grows 10 to 15 feet tall. Another variety is 'Smaragd' (also known as 'Emerald') which grows 10 to 15 feet tall and 3 to 4 feet wide.
If you are replacing your evergreens this fall or next spring, select the aforementioned varieties that possess greater disease resistance or winter hardiness. Variety recommendations from Pest Resistant Ornamental Plants by Deborah C. Smith Fiola of Rutgers Cooperative Extension and Juniper Disease Susceptibility Ratings from Kansas State University .
This article originally appeared in the July 26, 1996 issue, p. 134.