Nick's Garden: give your lawn a spa treatment

Top dressing is a simple and inexpensive process that improves soil quality and encourages healthy growth.

In many of the UAE's parks, the lawns have been covered with a generous mixture of sand and aromatic organic matter designed to replace nutrients and improve the overall health of the grass.

Equivalent to a spa treatment for grass, this simple and inexpensive process improves soil quality and encourages healthy growth, writes Nick Leech

Finding the perfect spot for your picnic blanket is never easy, particularly if you're looking for a space that has just the right amount of shade, space and privacy for your family and friends in one of Abu Dhabi's busy family parks at the weekend.

Normally the main issue is that everybody else has turned up with exactly the same idea but in recent weeks this quest has been made all the more difficult because most lawns have been covered with a generous mixture of sand and aromatic organic matter that displays an almost magnetic attraction to the hands, feet and mouths of smaller picnickers.

The cause of this added complexity is a landscape maintenance procedure known as top dressing, a process that will be familiar to anybody who has spent time around golf courses and sports pitches but one that is employed less often by domestic gardeners.

But since the professionals are currently doing it, why not consider applying a similar treatment at home? Just think of it as a well-deserved and much-needed spa treatment for the lawn.

Top dressing is designed to achieve several things: to improve the quality of the soil and its structure, to encourage healthy growth by creating optimum conditions in the root zone, to improve drainage while removing weeds and moss and to smooth out any unevenness that may have developed in the lawn over time.

Top dressing will also help to compensate for the loss of nutrients that often results from the use of chemical fertilisers and, more commonly in the UAE, from leaching caused by overwatering. Most importantly, by improving soil structure and allowing both water and roots to penetrate deeper into the soil, top dressing can also help to improve drought tolerance, words not often associated with lawn turf. It's not a bad list of outcomes for what is, after all, a very simple and inexpensive process.

In the UAE, top dressing can take place at any time from November onwards and is best done when the grass is already growing and when there is still time for several cuts before the heat starts to take its toll.

An important issue to consider at the outset is whether you are top dressing primarily to even out a lumpy, heavily compacted lawn that has suffered from neglect and heavy traffic or whether you are aiming for healthier, more organic turf. If levelling is your goal, then you'll need to invest in a dressing that combines sharp sand with topsoil or loam. However, if you're after a general pick-me-up, then you should consider replacing the topsoil with well-composted organic material.

Before applying anything, you will need to work out how much dressing you'll need. To do this, measure your lawn and multiply its area by .01 (this allows for a 1cm covering). Then, the day before applying the mix, cut your grass to reduce the amount of dressing required to cover it. Not only will it cost more, but a thicker layer of dressing will make it harder for the grass underneath to emerge.

After mowing, rake to remove any unwanted debris and loosen any bare patches. Make sure your lawn is moist to work with before aerating it, ideally with a hollow-cored aerating tool. This will create channels in the soil that will allow air to penetrate it freely and circulate through the grass's root zone. Many people use a garden fork at this stage but this often leads to even greater compaction, the exact opposite of the effect you are trying to achieve. Once this is done, you are ready to apply the dressing.

The easiest way to spread top dressing is to start by shovelling it evenly over your lawn. Once the lawn is completely covered, don't rush in to level it off, but give it a couple of hours to dry instead. This will allow you to rub the mix in more effectively and you will be able to fill up holes rather than smoothing wet soil over the top.

Once it has dried, use a stiff broom or the back of a rake to work the dressing in, making sure you achieve an even spread. This can be done in any direction, just as long as you go over the whole lawn and pick up any excess with a shovel. The grass should still show through the dressing.

For low spots requiring more than a couple of inches of top dressing, existing turf should be lifted and, after filling, be replaced or the area should be re-seeded. In my experience a good top dressing mixture does some settling, so now water the area well and let the mixture settle for a day or two before going back to smooth out any new hollows or bumps that may have developed in the interim.