Why are the evergreen bushes beside my house dying?

Question Why are the evergreen bushes beside my house dying?

Answer The bushes beside your house are commonly referred to as "foundation plants" because they are planted beside the foundation of the house. Years ago, most houses were built up off the ground to prevent termites and water from destroying the bottom of the house. Rock and brick were used to lift the houses off the ground. It solved the moisture and termite problem, but people could see under the houses. Homeowners began to plant around the houses to keep neighbors from seeing the chickens, cats and dogs that were laying around under their house. Evergreen shrubs were used because they blocked the view all year long. Boxwoods (Buxus sp.) were frequently planted because of the heavy English influence on our early American ancestors.

In the 1950s, people began building houses on foundations that were solid all the way around a house. Even though it was not possible to see under a house, homeowners continued to plant around the foundation.

Over the past 25 to 50 years, the Japanese holly (Ilex crenata) replaced the boxwoods as the most common foundation plant. Many people still incorrectly refer to the Japanese hollies as "boxwoods." Sometimes the Japanese hollies are called by their cultivar names. The most common are 'Helleri', 'Rotundifolia', and 'Convexa'.

The Japanese hollies are susceptible to one disease that causes a problem. This disease, called "black root rot," is soil born and can persist for many years. Diseased plants usually decline over a period of months (or years) and frequently die during or following periods of drought.

Black root rot has been reported on many herbaceous ornamentals and several important vegetable and field crops, including bean, tobacco, and peanut. However, black root rot commonly affects only a few species of woody ornamentals.

Susceptibility to this disease varies among hollies. Yaupon holly (Ilex vomitoria) and American holly (Ilex opaca) are moderately resistant. Chinese holly (Ilex cornuta) and English holly (Ilex aquifolium) are highly resistant. There are many non-holly plants which are resistant to this disease as well.

Fungicide treatments may not be sustainable. Proper cultural practices may help to reduce plant losses. For example, raised beds and avoidance of poorly drained planting sites will decrease the occurrence of most any soil born disease.

If you have been seeing limbs and large areas of your foundation plants dying over the past couple years, then you need to consider replacement options. To prevent the neighbors from seeing the chickens under your house, replant with Chinese hollies. For more info about holly diseases, visit http://www.ces.ncsu.edu/depts/pp/notes/oldnotes/od7.htm

If you don’t have internet access, then call the Extension Office at 893-7533 or email me at gary_pierce@ncsu.edu

Gary L. Pierce

Horticulture Extension Agent

Harnett County