Top dressing lawns is another tool we can use to help our Saint Augustine turf in two different ways. The first reason to top dress a Saint Augustine lawn is to add organic nutrients to the lawn, and the second reason is to level an uneven Saint Augustine lawn. Top dressing lawn should never be done for any other reason.
Top Dress Lawns To Add Nutrients
This method of top dressing lawns involves putting down a thin layer of organic soil mixture. This process is used to add natural organic nutrients and minerals to the lawn, and is highly recommended for all lawn owners to undertake every so often to feed their lawns naturally and to boost and improve lawn soils.
The top dressing mixture is sold in bags at lawn care and garden stores, or high quality rich garden soils can be purchased in bulk supplies. The soil improver is applied to the lawn at manufacturers recommendations or otherwise as a thin layer over the top of the sod, and when completed - the lawn should look as though it has been dusted with most of the organic soil material sinking directly into the thatch layer.
The top dressing mixture is then watered into the lawn, and due to its thin application, it should almost disappear into the lawn after watering.
Do not use this organic top dressing mixture to level uneven lawns.
Top Dressing Uneven Lawns
Uneven Saint Augustine lawns should be top dressed with either a sandy loam soil or a clean free flowing sand with none or only minor organic material. Soil from a nearby garden bed may also be used if it hasn't had excessive organic matter added to it, this should be the same soil which is already under the lawn.
For shallow indentations, the top dressing material can be added to a depth which does not exceed around one inch at one time. If the depression is greater, then wait until the first top dress is fully covered with new lawn growth before applying another application.
Most of the top grass leaf should still be visible after top dressing, and care should be taken to never completely cover the lawn with top dressing sand.
The sand or soil is then levelled and watered into the Saint Augustine lawn.
Levelling Deep Indentations In St Augustine Grass
Deeper and large area indentations which may be more than 3 inches in depth should not be top dressed. Instead, a spade should be used to lift up the affected lawn area, and the top dressing sand or soil placed underneath the turf to achieve most of the levelling. Any slight unevenness which is left over can be top dressed. Maintain regular watering for 2 weeks after this lawn repair.