What Causes Yellow Stripes on Miscanthus Adagio Grass?

Fertilizer Burn

• Fertilizer burn is a condition that occurs when excess fertilizer is applied to the soil around a plant. This is an issue for traditional turf grasses, Japanese silver grass and other ornamental grasses. Excess fertilizer causes a buildup of salt around the base of the Japanese silver grass, which dries the plant out, leading to yellowing of the blades of grass. Avoid over-fertilizing, and water the area around the Japanese silver grass thoroughly to help dissolve the salts.

Pruning

• Japanese silver grass benefits from being heavily pruned before it begins to put out new growth in the spring. Grass stalks that remain from the previous season take up space and prevent newer growth from accessing nutrients and sunlight. This causes new grass stalks to become yellow. Cut back old grass stalks to a few inches above the ground and remove the dead stalks from the growing area to prevent them from hosting diseases.

Soil Conditions

• Miscanthus grasses are relatively drought tolerant, and can survive without regular applications of water. However, soils with a high salt content are a serious problem for Japanese silver grass. As with fertilizer burn, soil that has a naturally high salt content dries out the grass and causes yellow stripes to form on the blades. Avoid planting Japanese silver grass in areas with a high salt content, or modify the soil with fresh topsoil, frequent watering and mulch to keep the grass healthy.

Diseases

• Rust and anthracnose both affect Japanese silver grass, although their effects are usually mild and controlled through cutting back the blades. Rust is a fungal disease that causes reddish spots to appear on the blades of grass; over time, these spots can expand into yellow patches or stripes as the grass is damaged. Anthracnose is associated with poor soil conditions, and grows well in warm, moist conditions. It causes yellow stripes and brown spots to appear on the grass.