Declining centipede is still a major topic at the Extension Office this spring. Many factors can contribute to problems with grass that is moderately resistant to diseases and insects.
There is no ideal grass that grows consistently well in Lenoir County. Centipede is well suited because of our natural low soil pH and its need for minimal care. Many local residences are encountering problems with a failure to green-up this spring and a decline and death in spots. It is important to understand the factors that contribute to a healthy centipede lawn.
Centipede has nutrient requirements that are different from most other turf. It prefers an acid soil with a pH of 5.0 to 6.0. If the pH goes above this range the availability of iron decreases and the grass becomes chlorotic or yellow in color. High levels of phosphorous also make iron unavailable in the soil and the turf becomes chlorotic or yellow in color. Healthy centipede is naturally light green in color and the use of excessive nitrogen will push the plant into decline.
Centipede will decline with the build-up of thatch which is plant stems, stolons and roots. Thatch prevents water from penetrating into the soil, provides a good environment for insects and disease organisms and prevents new shoots of centipede from rooting deeply into the soil. A soft, spongy turf is usually an indication of an excessive thatch accumulation and the turf is more subject to cold damage, drought and desiccation. Thatch removal should be done cautiously because centipede is not tolerant of radical treatment. Core-aeration and dethatching reduce soil compaction and increase air and water movement in the soil.
A soil sample is a great way to begin evaluation of declining centipede. Boxes and information sheets are available at the temporary Extension Office on 347 North Queen Street in room 307. You can also check the NC State Extension Publication Catalog calendar for centipede care, and a comparison of grasses for NC.