Thatch decomposition during periods of hot, moist weather can generate sufficient heat decomposition by-products to injure or kill turf grasses. The vigorous growth habit of grasses that produce creeping stems. The creeping bent grasses and Kentucky bluegrasses, for example, have a tendency to produce more thatch. The more decay resistant stems and roots contribute more to thatch development than the leaves in all grass varieties. Fertilizer deficiencies produce roots and stems that are more resistant to decay.
Sufficient nitrogen is required for growth and to stimulate bacterial decomposition of thatch.
The other essential plant nutrients must also be present in the proper balance. Acid soil conditions reduce bacterial activity which may result in slow stem and root decay. Over watering causes a reduction in soil oxygen, reducing microbial activity necessary for thatch decomposition. Thatch Removal Practice thatch removal on an annual basis. If thatch becomes too thick, more than half an inch, renovation may be the only answer.