In most cases top dressing is done to correct poor preparation and lack of soil underneath or to fill in low spots and correct uneven areas in the lawn. If your lawn is well fertilised, healthy and even, then you don’t need to worry about top dressing.
Top dressing brings many benefits to a lawn that is looking a little lacklustre, including helping to reduce the accumulation of dead grass clippings and stems, known as ‘thatch’. It helps to increase nutrient retention, improves drainage and increases disease and pest resistance.
Should only be done during the growing season (this is when you need to mow your lawn weekly). The earlier in the season the better. Generally late spring to early summer is best.
On new lawns top dressing is generally not required, but can be done to fill in any gaps or holes. However we recommend that you leave it for a few months and most of those issues will take care of themselves. Occasionally after a settling period some areas of a new lawn may need a slight correction to desired levels. Fertilise a few weeks prior to top dressing to ensure maximum growth at the time. Use river sand or a top dressing soil mix. Using a higher proportion of organic material for sandy soils is a good idea.
For established lawns that need top dressing, prior to doing so mow low with a rotary mower equipped with a catcher. Aerate or core your lawn, spread the mix evenly over the desired area, then rake, level lawn or broom it into the lawn profile. Never top dress more than 1cm in a single application, making sure the grass tips are still exposed.
Your lawn needs a firm base that allows water movement downwards and allows for water retention, so the turf roots system can develop and establish. The aim is to promote a healthy root system that will protect the turf from weather conditions such as droughts and winter frost. When top dressing to improve the soil profile, we recommend using a sand/loam/compost mixture.
For top-dressing material for level improvement, we always like to use washed or screened sand. It doesn’t compact quite as hard as brickies sand. It is generally easier to screed and level due to the lower clay and silt content and reduces the likelihood of the surface crusting and become hydrophobic.
For more hints and tips on top dressing your lawn check out our article here.