Perth's sandy soils are some of the most difficult in Australia to be able to maintain a healthy lawn on. New lawns can look great for a time, but then fade, get patchy, dry out and good money after bad starts to be wasted on upkeep.
This article is about the sandy soil treatments needed at the start of laying your lawn so your new lawn looks great for the next 30+ years.
That's right, with the right sandy soil treatment approach, it is possible to have a lush green lawn on sandy soil even during the hottest summers.
Let's start with the 2 PROBLEMS we have to overcome
Sandy soils have poor water retention
Sandy soils are water repellent / hydrophobic
And here are the money-wasting solutions that only work for a time
Using wetting agent products every summer period
Using ONLY organic matter treatments as part of soil preparation
Removing your sandy soil and bringing in organic matter soil treatments with an insufficient clay content of the right type.
I see it all the time around me as new houses are built. The contractors will either remove a truckload of dusty dry sandy soil and then bring in dark organically enriched soil as the foundation for the lawn.
Or, the sand is prepped with wetting agents and a tiny amount of organic material before laying the lawn.
So, what exactly is wrong with this approach?
Now, nearly everyone says that to improve water-holding ability of sandy soil, you need to add organic matter. This is correct
organic matter breaks down...
AND is used up by plants and micro organisms...
sandy soil with no remaining organic matter.
Becomes water repellent again in dry hot summers...
Conclusion: Organic matter is a temporary treatment for water repellent sandy soils and not a permanent one.
Do You Get The Picture?
Organic matter will get used up and needs to be re-added. But you cannot put it below your now old faded, drying lawn without digging up your lawn: And that's not going to happen!
This process takes a few years so homeowners don't often make the connection. Especially if they move house every 5-7 years.
So, What Is The Solution?
The solution is clay, Kaolinite Clay. Clay that disperses, not clay that clumps. Clumping clay is the stuff in kitty litter. Dispersive clays are kaolinite clays that WA farmers are digging up and mixing within the top 30 cms of surface soil to get amazing crop yields.
Ben from Ben's Landscaping in Perth writes "I use a sandy soil treatment on all my new lawn installations in Perth's sandy soils.
He also says "This (WATER REPELLANCY) is a significant issue in WA especially if no clay was added to the lawn prior to laying"
Why Add Clay Treatments to My Sandy Soil
Clay particles are tiny and coats the sand
Clay absorbs and holds onto water for longer periods of time
Clay does not disappear or get used up
Clay (Kaolinite Clay) turns sand into soil
How Much Clay?
Before laying your lawn, get a delivery of Soil Solver Clay Plus Minerals to be delivered and mixed through your existing sandy soil.
There is no need to spend money on trucking out this sand. Use that money instead for amending your soil with a treatment of Kaolinite clay, silt, and minerals ("Soil Solver Clay Plus Minerals") added to your sand, which will transform it.
Our recommended amount is 10-15KG of Soil Solver Clay Plus Minerals (A mix of clay, silt, and rock minerals) per 1 square meter to get the required clay content.
This is then mixed through. (See our table below)
What Is The Result?
The result is a soil composition treated with sufficient dispersive clay to permanently stop your soil from ever becoming water repellent.
A soil that will hold onto water
A soil that will now hold onto nutrients
A soil that will require less watering and less fertilising for your lifetime
A soil that requires no expensive annual wetting agents
A soil that enables healthy mycorrhizal fungi and microorganisms to thrive.
A beautiful lawn year after year for decades. With less watering, less fertiliser, and zero wetting agent costs.
Here is what L. Doherty has said on Facebook. back in 2016. Even the TV Show "Garden Gurus" have used her lawn as an example of a water-wise lawn.
"We used Soil Solver on our sandy block when we renovated and landscaped our home 5 years ago. We have NEVER needed to use a wetting agent since then (despite our having a long, dry summers). The lawn is thick and healthy and the kids love playing on it. I would highly recommend using Soil Solver if you have sandy soil."
In an update in 2022, ten years on L. Doherty confirmed again that they have never needed to use a wetting agent in the last decade and only fertilise once a year. They are still loving their lawn.
Easy Soil Solver Clay Plus Soil Treatment Volume Calculator Guide
4 bags clay and 3 bags of compost - treats up to 8 sqm
8 bags clay and 6 bags of compost - treats up to 16 sqm
12 bags clay and 9 bags of compost - treats up to 25 sqm
17 bags clay and 12 bags of compost - treats up to 35 sqm
500kgs of bulk clay plus 18 bags of compost - treats up to 50 sqm
750kgs of bulk clay plus 27 bags of compost - treats up to 75 sqm
1000kgs of bulk clay plus 36 bags of compost - treats up to 100 sqm
1250kgs of bulk clay plus 45 bags of compost - treats up to 125 sqm
1500kgs of bulk clay plus 54 bags of compost - treats up to 150 sqm
To find out more or ask us a question, please send us an email or call us during office hours to find out about the best sandy soil treatments for your new lawn.