Sunday, March 9, 2008

Landscape - Leyland Cypress Problems

Leyland Cypress trees were planted extensively in Delaware as windbreaks and screens over the last 15 years. It is a quick growing and attractive evergreen. Unfortunately, many of them are dying now and replacements must be sought. Some information on the problems with Leyland Cypress follows

Leyland Cypress Problems

Problems with established trees began cropping up several years ago, and the incidence of damage from disease and insect pests has increased every year. Seiridium canker, Botryosphaeria dieback and Cercosporidium needle blight are becoming increasingly common in landscapes as are infestations of bagworms and spider mites. Because of the height of the plants, treatment is difficult or impossible for most homeowners.

Other problems occur simply because Leyland cypress are often seen as the one solution for all screening needs and are planted in situations inappropriate for them. Planting in poorly drained or wet soils, or where excessive overwatering occurs often leads to fungal root rots. Leyland cypress requires full sun to grow well, and when planted in shade, rapidly thins and sheds lower branches. Failure to realize how very tall the plants become (60 to 70 feet tall) leads to trees being planted in improper places, such as under overhead utility lines where a shorter screen would be quite adequate. The desire for instant screening often leads to trees being planted too closely, which results in overcrowding at maturity. Overcrowding leads to problems with poor air circulation, increasing the possibility of disease occurrence and shading out of lower branches.

In addition, Leyland cypress is rather shallow rooted and is susceptible to storm damage (trees topping over in storms). The shallow rooting also means that Leyland Cypress are very susceptible to drought. Many trees were lost last year due to the dry weather.

Information on good alternatives to Leyland cypress will be posted in the future.

Information taken in part from "Leyland Cypress Alternatives" a factsheet from the Clemson University Home and Garden Information Center

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