Is Artificial Grass Suitable for Tropical Gardens?

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Tropical back yard with pool and artificial grass lawn
A tropical back yard with an artificial grass lawn. Image: © Cassanas Photography

For many gardeners in the developed countries of the tropics, a well-maintained lawn is often the showpiece of their front gardens, just as is it in temperate climates. But I’m not a fan of lawns in the tropics because I believe tropical gardens can be fully landscaped with trees, shrubs and groundcovers, negating the need for high maintenance lawns. I am even less of a fan of artificial grass.

Artificial grass – or synthetic turf as it is sometimes called – costs twice as much as natural turf and is difficult to lay properly. Most artificial grass manufacturers recommend that purchasers engage the services of professional synthetic turf installers to ensure that the job is done properly, and this will double the price again.

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That said, there are a few circumstances that can justify the use of artificial grass. In the desert regions of the dry tropics, the intense summer heat can make it extremely difficult to keep a lawn looking green, and in some locations water restrictions may make that impossible, even if you are prepared to pay expensive water bills.

In many such countries, front yards consist of large expanses of concrete with a few garden beds, planters, or pots of drought tolerant plants around the sides. In such circumstances, artificial grass can look much better than concrete, whether it is left bare or painted.

Woman in hardware store being shown rolls of artificial grass
There are many different types and qualities of artificial grass. Image: © Alpha Prod

In the wet tropics, if you must have a lawn, I do not recommend artificial grass. Whilst most manufacturers provide product guarantees for 7-10 years and sometimes more, after one or two wet seasons, the heat and humidity of the tropics invariably starts to make the artificial turf look tatty, and in some cases problems with molds occur during the wettest months when the turf never really gets the opportunity to dry out properly.

There are premium artificial turfs available in some countries, and if professionally installed might give you five years before they start to give you problems, but keep in mind most of these products are designed for use in temperate climates, not the wet tropics where temperatures are much higher all the year round, and there are many more insect pests and fungi that can accelerate the deterioration of the artificial grass.

Some people who have installed artificial grass have also complained that in the dry season it is too hot to sit on. In northern Australia there was a case a few years ago where a child badly burned the soles of her feet walking on artificial grass in the middle of the day. That would never happen on a natural lawn.

A lawn made from artificial grass does tend to become a heat sink in the tropics on very hot days, causing temperatures around the house to rise higher than would be the case with a natural lawn. And another downside associated with artificial turf is that it causes the soil under the turf (or under the concrete if it’s laid on concrete) to ‘die’.

Bare feet walking on artificial grass lawn
Artificial grass can become hot and burn the feet in the tropics. Image: © Kolombo Castro

The soil in our gardens is alive with trillions of micro-organisms, and they all play a part in keeping our plants healthy and the garden looking lush. But that soil needs oxygen and moisture to stay healthy. The more concrete slabs there are, or areas covered in artificial grass, the less healthy the whole garden becomes because there are so many ‘dead’ areas.

Some gardening writers recommend using artificial grass in areas around trees where there is too much shade for real grass to grow, or along the side of the house under the eaves, or on a front driveway if it is not fully concreted (that is the type with just two strips of concrete for the car wheels – they claim that having artificial grass between those strips makes it easier to maintain).

I don’t agree with any of those recommendations. Around trees there are plenty of shade-loving groundcovers that tropical gardeners can use to keep down weeds. And they enhance the health of the soil. Under eaves and on driveways it is better to use stones rather than artificial grass because stones will permit oxygen and water to get into the soil underneath to help feed all those important micro-organisms.

You can probably see now why I am not an advocate of artificial grass. Whilst there are advantages of synthetic turf (lower maintenance and savings on water, fertilizers and weed killers being the main ones), for me the ‘cons’ far outweigh the ‘pros’. Of course, if you live in a condo or town house and do most of your gardening in pots on balconies or patios, then laying artificial grass can certainly help make that area ‘pop’ with a bit of color. Personally, I prefer neutral stone finishes on balconies and patios, but I can understand why those with children or pets might prefer to use artificial grass.

Shady garden area with artificial grass
A shaded patio area that’s been ‘carpeted’ with artificial grass. Image: © Surked

Another area where I accept that artificial grass can be put to good use is a children’s playground area. If you have part of the garden set aside for swings or a trampoline, it’s hard to keep natural grass looking good around those. Synthetic turf can be cut to go around and under playground equipment, just as they do in many city parks. A rubber underlay can make the artificial grass softer to fall on in case of playground accidents. It can provide a cushioning effect as good as natural grass.

Some people prefer to use artificial grass around swimming pools as salt or chlorinated water from the pool splashed onto the surrounding lawn can cause unsightly patches in natural grass. But most swimming pools have a concreted or tiled surround which is usually sufficient to contain the splashes. For example, in the header photograph of this article, where the entire lawn is made of artificial grass, I would consider the wide concreted surround sufficient. But having artificial grass there does avoid grass clippings being blown into the pool if it was a natural lawn which would need mowing from time to time.

How To Install Artificial Grass

Installing artificial grass can be a time-consuming process, especially if the width of the area to be covered requires the rolls of synthetic turf to be joined. There’s a lot of skill involved in both the preparation processes and the actual laying, which is why I recommended earlier that you get professionals in to do the job, despite this doubling the price.

But if you do have previous building or landscaping experience and you feel that you could tackle the job to save money, then there are plenty of videos available online to help guide you through the process. The key to a successful job is as much in the process of preparing the ground for the artificial grass, as it is in laying the synthetic turf.

If laying over concrete, you must ensure that there is a very slight slope in one direction to ensure that rain will flow off the artificial grass into a drain capable of handling the volume of water that will fall on the artificial grass during a heavy wet season downpour. There should also be no sections of the concrete where water could puddle because water will not drain through artificial grass.

Water puddling on badly installed artificial grass
Puddling after rain on a badly installed artificial grass lawn. Image: © Konskrit Preechachanwate

If your concreted area does not already meet those conditions, you will need to add a layer of cement over the top to provide the proper fall to the drain. That cement will need to be mixed with additives to ensure that it adheres properly to the concrete and doesn’t crack or separate from the concrete in the ensuing years. It might sometimes be better to add another layer of concrete, at least 3cm think over the top of the existing concrete to achieve the best possible foundation. But that adds to the cost.

For areas that are not concreted, the ground must be prepared to provide the same type of fall for drainage. This involves removing all loose rocks, stones and any organic matter (because that would rot under the artificial grass and cause dips) and then compact it with a mechanical compacter. In some countries those machines are known as ‘wacker-packers’ and can be hired by the day from builder’s supplies yards.

After compaction of the ground, it is necessary to add a sub-base of crusher dust or coarse sand. This must be a minimum of 5cm thick after compaction. It’s recommended that the area be thoroughly compacted twice, with the material being dampened between the two compactions. Then a final thin layer of fine sand should be added, and a final compaction carried out.

Throughout these processes it’s important to keep checking levels with string lines and a long builder’s level because it’s almost impossible to determine whether the fall is correct with the naked eye. Only the most experienced landscapers can do that. When the surface preparation has been completed, it should be allowed to dry before rolling out the synthetic turf.

Wacker packer compacting gravel in back yard
Compacting a base of fine gravel with a ‘wacker packer’. Image: © Ceri Breeze

Different manufacturers have different methods of joining their synthetic turf using special weatherproof tape, glues, or pegs. Follow the specific manufacturer’s instructions carefully because one method of fixing may not suit another manufacturer’s product, as the composition of the material used in the manufacturing process varies considerably between manufacturers. There is even one manufacturer that partly uses sugar cane waste to make their product less synthetic and more sustainable.

After rolling out the synthetic turf and before fixing it, you should allow a few hours for the turf to settle and ‘breathe’. This makes it easier to get it to lie flat without any bumps or kinks. Use a heavy Stanley knife with new blades to cut the synthetic turf if it needs to be fitted around garden beds or other obstructions.

After the synthetic turf has been laid and fixed into place, you will then have to spread sand over the top of the artificial grass. This is called the ‘infill material’ and is designed to do two things. Firstly, it gives the artificial grass a more natural look, and secondly – and most importantly – it adds weight to the synthetic turf to help to hold it in place and stop it moving.

That weight can be quite considerable over the area of an artificial lawn because recommended infill application rates range from 10kg to 15kg of sand per square meter depending on the length and density of the type of synthetic turf being installed.

Roll of synthetic turf on artificial grass lawn being installed
For a large artificial grass lawn it’s best to use profession installers. Image: © Stor24

Whilst the addition of the infill material is not as critical as the site preparation and actual laying of the synthetic turf, it still needs to be done properly if you want your new artificial grass lawn to look like a real lawn (at least from a distance). That involves lightly applying the required amount of infill sand in 2-3 layers, as evenly as possible, and then gently brushing it in a direction that is against the ‘grain’ of the artificial grass blades.

If you can relate the artificial grass to a carpet, where we talk about the height of the ‘pile’, then the objective of infilling is to have the sand covering all the (usually black) plastic material to which the blades of ‘grass’ are attached but not more than halfway up the pile. If you follow the manufacturer’s instructions and spread the infill sand smoothly, that should be readily achieved.

The most important rule about applying infill sand is to lightly sprinkle from above. Never ever dump the sand on the artificial grass and attempt to spread it out from there. If you do that, the blades of artificial grass under where you dump the sand will become compacted and it’s almost impossible to get the pile looking even again, and you’ll have a patch of your artificial lawn that looks different to the rest.

It’s usually recommended that if you apply the infill sand in three layers, you leave the final layer until after it has rained, as water on the first two layers will help it to settle before the final infill layer is added. At the end of each wet season, it is usually necessary to top up the infill sand as some of it may get washed away during heavy tropical storms.

As I’ve indicated at several points in this article, I’m not a fan of artificial grass and I think there are only limited reasons why it should be used in the tropics. But I accept that not everyone will agree with me and there will be some for whom an artificial lawn has great appeal. To those persons I can only emphasize the benefit of having professional installers do the work, because if you don’t get the installation right, your lawn will look just that – artificial.

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