The magic of wetting agents for lawns
Author: Stefan Palm Date Posted: 31 January 2024
Most soils don't wet evenly. While easily solved, water repellency in lawns is a very common problem and can lead to dead and dying patches and a generally unhealthy lawn. Using wetting agents as often as you fertilise will transform your lawn.
I’ve often said that if I had to choose between applying a wetting agent or a fertiliser to my lawn, I’d choose a wetting agent. It’s a bit of a dramatic statement, and, of course, your lawn needs fertiliser; however, soil-wetting agents are often overlooked in the management of lawns, which is a shame because they can transform the performance and appearance of your lawn.
To start this conversation off, I'll point out a few things that are immediately obvious, but help to frame the basis of this blog.
- To have a healthy lawn, it needs to be growing in a healthy, freely draining, non-hard-setting soil
- Lawns need regular water to grow
- Lawns grow best when they are fertilised regularly
I’m pretty confident that most people who love their lawns will know these things and will put in the time and effort to ensure they’re on top of them, however there is a critical reality that can undo much of this hard work.
Here it is: Most soils don’t wet evenly.
You might read that statement and think, “So what?” but let me assure you, recognising and understanding this will change the way you manage your lawn. The best advice I can give you for the long-term benefit of your lawn is to assume it has some level of water repellency and treat it accordingly.
What is water repellency?
Water repellency in soil is where all or part of the soil repels water instead of absorbing it.
When water lands on your lawn (either by rain or irrigation), it ideally does some critical things:
- It penetrates deep into the soil so that the lawn roots can take it up
- It carries nutrients on the surface (e.g. fertiliser) down through the soil to the root zone of the lawn, where it can be taken up
- It washes out impurities in the soil (such as salt)
The problem is that this often is not the case - not in a consistent way, anyway. Most soils have an element of water repellency, which means that water can end up running off instead of penetrating in, carrying with it nutrients that were intended to go down to the root zone. Extending this thinking further, your soil can remain dry and nutrient-deficient despite being watered and fertilised, leading to dead and dying patches and a generally unhealthy lawn. If you have dead and dying patches in your lawn and are watering regularly, it probably won’t occur to you that the problem is water-related!
To back this up, we've conducted thousands of core sample tests for our customers. Statistically speaking, more than 60% of lawn problems can be associated with a lack of water or water repellency issues. When customers ask us to diagnose problems, it’s often with great surprise when this is revealed. It’s important to recognise that just because you watered your lawn or it rained doesn’t mean that the water penetrated deep enough into your soil to satisfy the requirements of your lawn. Missing this will lead to wasting both water and fertiliser and can lead to an unhealthy and patchy lawn. Solving this problem is really simple and cheap – but more about that later.
Depending on the nature of your soil, the problem can range from total water repellency, where the entire surface becomes waxy and repels water, to less severe issues, where only patches of soil repel water. In these instances, some soil areas will absorb water well, and others will repel it completely. One thing is for sure, though: most soils do not absorb water evenly. With this in mind, water repellency has the potential to undermine or even negate your fertilising and watering efforts.
Understanding and treating this is called Soil moisture management and is critical to the health of any lawn. There are many elements to soil moisture management, but the one we're focusing on today is water repellency. Managing water repellency will:
- Ensure the even penetration of water through your soil
- Ensure the even filtration of nutrients through your soil
- Encourage your lawn to grow a deep and consistent root zone
- Help reduce the build-up of unwanted contaminants in the soil
Managing water repellency in soil:
The best way to manage water repellency in domestic lawns is by regularly using wetting and water retention agents. If you use these types of products through the warm months, combined with a regular watering and fertilising routine, you’ll be amazed at the difference you’ll see in the health and appearance of your lawn.
So, what's the difference between wetting and water retention agents, and how can you utilise them to ensure a healthy lawn with less water?
Liquid wetting agents are used to treat lawns that are non-wetting or repel water or simply as a treatment to ensure the even penetration of water. They break the surface tension of water and help to dissolve waxy and oily residues in the soil. This allows water to freely and evenly soak in without wastage or runoff. Wetting agents are critical to lawn health, especially during Summer.
- Instantly overcome non-wetting or water-repellent soils
- Allow water to penetrate deep into the soil
- Ensure that water penetrates evenly across the entire surface
Apply a hose on wetting agent such as Paul Munns Betta Wet in November and January every year. Available in a 2L hose on pack, which covers 100 square metres
Water Retention Agents:
While most people have heard about wetting agents, water retention agents may be a new idea to you. As the name suggests, these products have the capacity to store water in the soil, meaning you won't need to apply water as much or as often. Water retention agents work in lawns in a similar way to how water storage crystals work in gardens, the difference being that water retention agents are applied as a liquid (either sprayed on or via a hose on applicator) and then cure in the soil where they absorb and hold onto water.
If your soil is not water-repellent, you can simply use a water retention agent as part of your management program in an effort to conserve water, especially in situations where water drains quickly from the soil. If you have water-repellent soil, you’ll have to use a wetting agent before using a water retention agent. Otherwise, the water retention agent will not be able to evenly filter down into the soil profile.
Water retention agents:
- Can reduce irrigation requirements by half
- Can increase moisture content by up to 5x in the root zone
- Last for up to 6 months
For best results, apply a water retention agent such as SST Bi-Agra once per year in November. Available in a 2L hose on pack, which covers 150 square metres. Remember, if your soil is water-repellent, you must apply a wetting agent first. Once watered in, you can apply Bi-Agra straight away on the same day.
To sum this all up in the most simple way possible, managing how water penetrates into your soil is an essential step in maintaining a healthy and green lawn. In doing this, you'll save water, fertiliser and time. If you'd like to chat more about this, please reach out at email@example.com