Pachysandra Diseases

Pachysandra is a dense ground-cover that requires shade or partial shade. Mature plants are susceptible to Volutella pachysandrae, a severe fungial disease. Insect infestations are also a problem with this plant. They can become infested by Euonymus scale, San Jose scale and Oystershell scale. Management of these diseases and infestations are possible through removing and destroying diseased plants as well as with the use of fungicides.

Characteristics

Pachysandra is also known as Japanese pachysandra or spurge. It is classified as Pachysandra terminalis. This plant is a evergreen perennial, which means that it lacks woody stems but their foliage, which is broad-leafed, does not die back in winter. Although the foliage may yellow slightly during the winter months. Pachysandra is used as a ground cover and can be grown in zones 4 through 8. They are an excellent plant for weed control and are best when grown in partial to full shade. They thrive in a well-drained acidic soil rich in humus and do well with medium moisture.

Diseases

As part of the Boxwood Family, the primary cosmetic or serious diseases that the Pachysandra are susceptible to are leaf blight, stem cankers and leaf spot. The primary pest is nematodes. These plants will die if they are planted in full sun or if they are placed in wet areas. Severe or prolonged spring or summer rains will cause Volutella pachysandrae, which will lead to stem canker, severe leaf spot and leaf blight. Due to their dense foliage, any infestation will be hard to eradicate because of the extreme difficulty in reaching the undersides of the leaves with insecticidal sprays.

Fungial Disease

In the Northeast, Volutella pachysandrae (Volutella blight) is what causes the most destruction to pachysandra. This fungus attacks both the leaves and the stems of the pachysandra plant. Signs of this disease are leaves developing irregular brown or tan spots or blotches. These blotches very often have lighter and darker zones with brown outlines. The blotches increase in size until the entire leaf is engulfed, causing it to die. The stems are en-girdled with stem cankers and the entire plant dies. Usually this occurs in circular patches throughout the ground-cover bed. Generally plants that have had insect infestation, have suffered injury through the winter season, have recently been transplanted, are exposed to drought or are exposed to full sun are likely to have severe volutella pachysandrae.

Control of Volutella Pachysandrae

Remove and destroy all severely diseased plants. This disease is closely associated to stress, therefore in order to maintain healthy plants, you should pay close attention to environmental conditions such as drought and insect infestation. Be sure to water adequately and fertilize during the spring as well as thinning the bed so that there is adequate air circulation and light.

Insect Problems/Liabilities

The most common insect problem is Euonymus scale. To treat severely infested plants, mow and remove the clippings. This will allow the plants to regrow. You can also spray with a horticultural oil in mid-April (dormant treatment) or in early June and in mid-July controlling the scale. Other insect problems are San Jose scale and Oystershell scale.

Although this plant is known as an excellent ground cover there are some liabilities as follows:

1. Slow to establish.
2. Disease and insects pose a severe problem to mature plants.
3. Will retain leaves in the fall making fall cleanup a problem.
4. Must have shaded conditions.