20 Reasons Why Your Lawn is Not Green
For the past 22 years, I have visited clients and assisted them with turf and irrigation system problems. Over this time, I have developed one of the most efficient programs to restore these problems once identified by my diagnostic tools. This article covers the top 20 reasons why your lawn is not green.
1. The lawn does not get regular watering in the warmer months due to poor irrigation system design or damage to pop-up sprinkler systems.
Regular watering is critical and necessary for optimum growth and bright green colour.
Although summer active grass species can often survive through summer without any watering, they often look quite dead and lack colour and vigour.
Weekly watering regimes of 15- to 20-minute durations will return great outcomes on Kikuyu, buffalo and couch grass species. This will, of course, also depend on whether other underlying issues have been rectified.
Tall fescues, and finer leaf cooler seasons grasses, will require much higher amounts of water when temperatures exceed 30 degrees and soil moisture is depleted, as soil temperature remains elevated. At this time, lawn mowing should be adjusted with the aim of maintaining more leaf canopy ensuring the root system of the grass is shaded from our harsh sunlight. More leaf canopy will also retain more moisture and allow the plant to feed itself better due to a greater capacity to photosynthesise more energy.
Poorly designed pop-up sprinkler systems can be the cause of dry spots in the lawn. Care should be taken to ensure failure rates are kept as low as possible, with anything above a 50% failure rate redesigned.
Don’t forget to check your pop-up sprinklers on a regular basis. Heads that are damaged, blocked or have been hit with the snipper cord, and accidently closed, will cause dry patches to emerge on your lawn, especially in a hot weather event.
2. Weed infestations compete with turf and grow in dead patches
Weed infestations in lawn occur throughout the year, but can be more noticeable in spring, as ground temperature rises causing seeds to germinate.
There are two main categories of weeds: dicotyledons and monocotyledons. The dicotyledons are the broadleaf weeds species and the monocotyledons are the grass species.
When controlling weeds in the lawn, it is especially important to use a selective herbicide, one recommended for your species of turf and the weed in question. Avoid using a non-selective herbicide such as glyphosate.
Timing is another important critical factor when controlling weeds in turf.
3. Non-selective herbicide used on lawns to kill weeds.
This is an all too common sight when examining lawns, and generally comes out of a lack of understanding.
When glyphosate products are used on a lawn, they will kill the weeds and the grass around them. This will cause dead patches in the lawn until the rhizomes grow back through the dead area. In the case of a seeded grass species such as Tall fescue, there will not be any recovery.
4. Lawn planted on the wrong type of soil.
Lawns are often planted on heavy garden soils that do not freely drain. Coupled with a lawn that has an excessive thatch layer, this can create many issues particularly for summer active grass species when they are dormant in winter.
The best soil medium for planting lawn is large particle sand that doesn’t have too many fine particles—otherwise it will become sludge. This will produce a superior lawn and will drain freely in winter when turf is exposed to harsh cold conditions.
5. Contaminants under the soil.
When probing below the turf surface, the problem is often identified quickly.
Bricks, road base concrete, rock, pavers or dolomite under the turf will poison your ecosystem under the lawn surface making it a continual struggle to maintain a green healthy lawn surface.
The solution in most cases is to dig out a substantial amount of soil to remove all rubbish. After replenishing the area with new soil, a new lawn can then be re-laid.
6. African lawn beetle damage through the warmer months.
Yes, this little creature is still our worst turf pest in South Australia, wreaking havoc from about the second week of October until about March to April subject to ground soil temperatures.
Quite often people don’t realise they have had a strike until later in the season when turf has died off, and weeds start to develop in the bare patches eaten out by the beetle.
Definitely worth putting a 6-month residual treatment on your lawn in October if you are serious about maintaining it in pristine condition through the warmer months.
7. Excessive thatch in the lawn’s surface.
All grasses that produce a runner (stolen or rhizome) produce thatch. Thatch is much like our skin that dies and replaces itself with new cells. In the same way, the runners die, and new ones grow on top of the old ones thereby producing what we call thatch or a thatch layer.
Some thatch is helpful to the lawn to retain moisture and shade the root systems in the hotter months. However, when this layer becomes excessive it becomes a problem. It slows down infiltration (the movement of water through the turf surface) and provides a perfect environment for fungal spores and insects. It also causes aesthetic problems such as scuffing and scalping patches in turf.
8. Poor nutrition, element deficiencies and incorrect PH.
Just as poor diet in people will produce poor outcomes in their health, the same is true for grass if the soil is depleted in nutrition.
Element deficiencies can reduce the uptake of other minerals and elements having a “knock on” domino effect that reduces the ability of our grass to get to the vital elements required for optimum health and growth.
If the soil is in the wrong PH range for the grass growing in it, the lawn’s ability to absorb certain minerals is greatly reduced.
Without some of these critical elements, plants can yellow off, becoming weak and prone to disease and environmental damage.
9. Hydrophobicity (non-wettable soil).
Have you ever left a bag of potting mix in a shed that gets hot in summer for a prolonged period and when you attempt to pour water into it, the water seems repelled? This is a good illustration of hydrophobic soil.
So, what causes your lawn to become hydrophobic?
Certainly, allowing soils to dry out completely will do the trick. The breakdown of plant materials on lawn surfaces will produce this water repelling effect.
It is important to remember that all plants have a waxy layer to protect them from the elements and diseases. When plant matter dies and falls to the ground, it leaves this waxy layer as a residue on the ground. Over time, this waxy layer can build up much like fat in a frying pan and like that fat, it deflects water.
Plants and trees overhanging the lawn, particularly blossom fall, will cause a great deal of the non-wetting issues. However, the natural build-up of the thatch layer also creates hydrophobicity, which contributes to most non-pathogenic dry patches in lawns.
10. Compacted soil under the lawn’s surface.
This is a very common problem particularly in areas of high traffic, or when vehicles are parked on the lawn.
Soils with a high clay content are particularly vulnerable to compaction.
As soil becomes compacted, the precious pockets of oxygen become flattened leaving carbon dioxide and other gasses trapped under the ground and little oxygen movement under the soil.
This causes the soil to turn sour and stunts the grass’s growth, resulting in it dying off in patches.
If you observe the path the postman uses on his scooter across your lawn, you will notice the stunted effect caused mainly by compaction.
11. Lawn cut too low, scalped and crown of plant damaged.
Cutting height is quite important when maintaining a lawn area and is relevant to both the species of grass being cut and the time of year you cut.
Couch grasses are normally cut extremely low in summer, while tall fescues should be cut at the top level of your mowers setting.
The general rule of thumb is to cut a lawn at regular intervals relative to the growth rate of the lawn, and to remove one third of the leaf tip when mowing.
The type of mower used will also determine the frequency of the cutting. For instance, most rotary mowers can achieve good results on most lawns on a fortnightly basis. However, in summer at temperatures exceeding 30 degrees, cutting with a cylinder mower may require weekly cuts, or even cuts every 5 days. This will ensure that excessive amounts of grass are not removed.
If this pattern of mowing is followed and scuff marks are occurring on the lawn, this may indicate the thatch layer is too high and the lawn needs to be scarified or dethatched.
The other reason for scalping can be mowing too infrequently. For instance, mowing too late when grass is highly active causes grass to grow too long before it is cut. This is common in spring, when soil temperature starts to rise and grass has a growth spurt.
Edging lawns on a 45-degree angle, or operating the brush cutter too quickly, can cause scalping to the crown of the plant, causing the grass plant to turn white, and dye off on the edges. This will eventually see the creation of thick unsightly gaps between the concrete edge and the lawn.
12. Galahs and other birds eating your lawn.
This problem can be quite frustrating. Just when you get your lawn seemingly perfect, along come the birds and decimate your beautiful showpiece, leaving dead bowl-like patches that can become quite large in area.
Usually, the birds that are damaging the lawn are the hooked beak parrot variety. These birds chew the rhizomes (runners) in the lawn which are juicy and provide an easy food supply to birds when food is a bit harder to find.
The easiest way to stop these damaging birds is to purchase some rubber snakes, and place them over the lawn and garden areas, on and close to the lawn.
If you are experiencing Magpies on the lawn from October through to March, they are most likely listening to the ground and drilling into the soil with their beaks to eat beetle grubs or worms, leaving behind little holes. These birds are not damaging the turf; in fact, they may be helping reduce the amount of lawn beetle grub in your lawn which they find very tasty.
13. Dog urine particularly from female dogs.
This is a very common sight and one that needs to be confirmed usually with the owner, and ruled out, before jumping to conclusions about other suspected causes of these dead patches. The problem lies in the amount of urea in the urine that burns the turf and poisons the ground.
It is hard to bring a solution to this problem, as dogs are usually habitual and will often return to the same spot, thereby making the problem worse.
Female dogs tend to have a worse effect on the grass, as they’re more likely to return to the same spot or they may have a higher urea content in their urine.
A litter box regularly maintained can be a useful tool in dealing with this issue. With some training, it can deter the dog from the lawn.
Another way to deal with the problem is to soak the area with water as soon as you see your dog in the act. This will dilute it and reduce the effect of the urea burning it.
14. Root intrusion.
When roots from trees, creepers or shrubs encroach into your lawn area, you will soon see the negative effects of the intrusion.
Firstly, the amount of water being taken from your lawn will cause your lawn to dry out quickly. This will require extra water and fertiliser to bring the lawn up to a better colour and growth.
The only problem with this approach is that by taking this action, you are watering and fertilising the intruders. And thus, speeding up the inevitable.
Eventually, your lawn is so filled with roots that dead patches start to get bigger and the lawn looks sick and dry. Essentially, you’ve been pouring on water to no effect.
Most of the time, this type of lawn needs to be dug out and re-laid after root barriers and pruning have been attempted.
Removal of creepers and shrubs that cause this issue can often be undertaken, and quite often the neighbour who is quite approachable, is unaware of your misery.
15. Shade over the lawn area.
If you are selecting a new lawn that will be laid in a yard with some shady areas in it, something you need to be aware of is the shade tolerance of the turf you select.
There are quite a few seeded cool season grasses that you can use. However, these grasses are not that drought tolerant and will need more water than drought tolerant turf species. They will also require more work when hit with a beetle strike. In other words, they will need to be grown from seed.
There are certain types of soft leaf buffalo that grow quite well in a semi shaded position. If hit by beetles, they can be patched with instant turf.
It is important to understand couches and kikuyu do not grow under shady positions as they require a full sun position.
When maintaining a shade-tolerant lawn under the shady areas, a good tip is to lift the blades to a higher setting, allowing the leaf tip to grow longer and catch more sunlight. This in turn will allow the plant to produce more chlorophyll and stay greener in the shade.
Waterlogging is another common problem that is not always easy to cure.
Waterlogging is caused by poor drainage in the lawn. This can be because the soil is tight, and the type of soil is too heavy for water to pass through it. This is normally indicated by the appearance of moss growing in some of the areas of the lawn, as moss will not grow on free-draining soil.
Inadequate drainage from your lawn area could be another reason, allowing water to pool, instead of running away to a drain. Most of the time, the installation of some type of drainage system is required to remediate the problem.
17. Cars parking on the lawn.
No one wants their car on the street, right?
Unfortunately, when there are too many cars and not enough car park spaces, someone parks on the lawn.
As the car returns to the same area, the ground gets more and more compacted until the grass dies and dirt patches emerge.
There would be no point attempting to remediate the area until the car parking has ceased.
18. Fungal diseases.
Certain weather events and the lack of good turf management practices usually lead to fungal problems on lawns.
Fungal issues can also be quite specific to particular species of lawn.
Prolonged hours of leaf wetness, more than 11 hours for example, can be the trigger that allows fungal spores to enter the grass plant thereby commencing the growth of the fungal outbreak.
Treatment can be generalised; however, accurate diagnosis is a better way to target the problem and remediate the disease quickly.
It has been said that fungal diseases on the lawn are not caused by one factor, but rather a collective compounding of many issues. For instance, too much thatch, poor drainage, dry soil, lack of water and poor nutrition. Grass that is cut at the start of a long duration of rain, causing an extended time of leaf wetness, could also initiate a fungal outbreak on your lawn.
The take-home message to lawn enthusiasts would be to do all their turf management well if they want the best results.
19. Fuel, chemicals or oil and paint spills on the lawn.
The fuel problem is normally caused by poor handling of fuel or machinery wear.
I have always maintained never fuelling up a mower while stationary on a lawn. It seems obvious to most people; however, you would not believe how many people I have had working for me that needed to hear that advice.
Another one would be the wiper snipper. Some forgot to put the fuel cap back on after fuelling up. Or sometimes, the cap is worn out, trickling fuel on the lawn as it is edged—evident by a straight line of dead lawn closely parallel to the edge.
Chainsaws used close to a lawn, if placed on the lawn, can cause damage from oil leakage or burn the turf when placed on the lawn after use when the machine is extremely hot.
Always remember to inform your painter or builder and have in writing before he starts work, that it is not acceptable to wash brushes or paint pots on your lawn. Remind them that the lawn and the soil ecosystem under it is a living thing, and you don’t want it contaminated with paint. This would also apply to any building works that produce cement or builder’s waste. Your directive should always be clear: don’t put it down in the garden at all! Rather, take all waste material liquid and solid offsite, or straight into a skip.
Non-selective herbicide such as glyphosate can be another issue when spraying the garden and getting it on your feet, then walking over the lawn on the way to the other garden bed. Oops! The evidence is dead grass in the shape of your gardener’s size 9 boots. Busted!
20. Couch mite.
This one is not a common problem in South Australia. However, some sightings have been made in recent years, and they say it is becoming more of a problem.
This mite can’t be seen with the naked eye, so it is important to diagnose and treat it to prevent spread and further damage to turf.
For lawn maintainers, it is critical they understand the problem to avoid them spreading the mite to all their clients with couch grass.
So, What Now? Where to From Here?
If you suspect your lawn is suffering from one or more of these conditions, the best way forward is for me to come out and carry out my unique 17-point turf inspection.
Following up from this inspection, I can then tailor a program specific to your lawn’s needs and get back to you with all the details of the solution.
To make a booking, drop me a line via the Lawn Report Enquiry Form and I will get back to you with a time that is suitable.