The Concise Lawn Fertiliser Guide

Lawn fertiliser is a specialised type of plant food that helps to promote healthy growth in grasses. It is typically formulated with a combination of essential nutrients, including nitrogen (N), phosphorus (P) and potassium (K), which are vital for photosynthesis, cell division and root development.

Lawn fertilisers can come in a variety of formulations and release methods, depending on the specific needs of the grasses being fertilised. For example, slow-release fertilisers are ideal for long-term feeding, while fast-acting fertilisers can provide a quick boost of nutrients when grasses are under stress or when you want them to colour-up quickly.

Application methods and seasonal timing also vary depending on the type of lawn fertiliser being used, and the lawn variety you are caring for.

Liquid Lawn Fertilisers

Liquid fertilisers have the advantage of being able to be applied to both the ground and to the lawn foliage itself, also called foliar application.

The ground application will result in the roots absorbing the nutrients, whereas foliar application allows the plant to absorb the fertilisers through the leaves, making nutrients available for immediate use. The foliar application also provides for mid-season corrections, if your lawn needs a boost.

Liquid lawn fertiliser can be purchased as a concentrate, which needs to be diluted prior to application (this is the more cost-effective option) or purchased as a pre-mixed bottle that attaches to your garden hose.

Key benefits of liquid fertiliser:

• Uniform application
• Quick leaf foliage uptake when green-up is needed
• Seasonal application variances are available
• Can blend with other liquid products
• Easy to apply

For a good selection of liquid fertilisers, look at myhomeTURF’s online store.

Slow Release Lawn Granular Fertilisers

Granular lawn fertilisers are dry fertilisers that are made into a pellet form, often blended to get the desired ratio of nutrients needed for your lawn.

Most lawns respond well to a slow release granular fertiliser, which can feed your lawn for up to three months. One of the main advantages of this type of fertiliser is that it provides a constant source of nutrition, with no sudden spikes in growth and no nutrient-run off.

Key features of slow-release lawn fertilisers:

• The nutrients slowly, continuously release
• All the fertiliser’s nutrients are utilised following watering-in
• Use of low application rates (saves money)
• There is only a need to apply three times during the year (twice in spring and once in autumn)

For a good selection of slow release granular fertilisers, look at myhomeTURF’s online store.

Traditional Lawn Fertilisers

Traditional lawn fertiliser is often the cheapest lawn food choice but, not necessarily the best.

Key features of traditional lawn fertilisers are that:

• They require high application rates
• They only supply your lawn with short-term feed
• They create a crystalline or powdered appearance
• A spike in growth and greening occurs (a rapid initial response which tapers off quickly)
• They require frequent applications

Traditional lawn fertilisers also tend to dump their nutrient load immediately after watering into the lawn which often leads to high nutrient run-off into waterways and drains.

Application rates for traditional fertilisers are every four to six weeks and rely on the lawn to absorb the nutrients as they move through the soil.

However frequent applications of traditional lawn fertiliser can have detrimental effects on the soil chemistry and therefore health.

For a good selection of traditional fertilisers, look at myhomeTURF’s online store.

Organic Lawn Fertilisers

A ‘true’ organic lawn fertiliser is one that has been certified as 100% organic – so be sure to have that guaranteed on the label when purchasing. The simplest way to check that it is 100% organic is by looking for the Australian Organic Certified logo on the bottle or pack.

Organic lawn care tends to focus on continual soil improvement and ensuring soil health. Granular fertilisers such as Terralift TX Trace 3-6-2 20kg can provide all of the required plant nutrients (major and minor nutrients as well as required trace elements), buffer pH and toxic imbalances, and provide microorganisms that will ensure long term and permanent improvements to the soil. They do contain some inorganic fertilisers which help them to provide enough nitrogen to feed a heavy-use lawn.

Each lawn fertiliser comes with three macronutrients, Nitrogen (N), Phosphorus (P) and Potassium (K).

Depending on the type of lawn and soil quality, it will require a fertiliser that has a certain blend of these three nutrients to thrive.

Nitrogen (N)

• Nitrogen is usually the highest percentage found in fertiliser
• If your grass is beginning to look yellow in some areas, it’s likely to be Nitrogen-deficient
• Nitrogen has properties that improve the health of grass leaves and therefore help your lawn appear greener, thicker and fresher

Potassium (K)

• Potassium is required to help your lawn’s overall functions
• It is the key nutrient to strengthen cell walls and makes your lawn more durable to withstand extreme weather conditions.

Phosphorus (P)

• Phosphorus is used for the healthy growth of your lawn’s roots
• Only a tiny percentage is usually required

 The ratio of Nitrogen, Phosphorus, and Potassium (N, P, K) plays a part in determining the right fertiliser for your lawn.

Conducting a soil test will point you in the right direction in choosing the right fertiliser and NPK ratio for your lawn.

Fertilising your lawn ensures that there are adequate levels of nutrients in the soil, which in turn produces new leaves and roots. It is especially important to fertilise sandy soils as they tend to leach nutrients faster than clay and heavy soils.

Fertilising your lawn on a regular basis helps to ensure that your grass remains green and healthy.

When to Fertilise your Lawn?

You will get the best results from your fertiliser program if you feed  your lawn at least three times a year:

• early spring
• early summer
• mid to late autumn

If you decide to only feed your lawn once – this is best done during late spring or early summer.

Always select a fertiliser that suits your type of lawn and the time of year when you are fertilising.

Soil type and irrigation frequency will also determine how much and how often you need to fertilise your lawn. For example, sandy soil requires more frequent fertilising than clay soil, and if you have an irrigation system in place, you may need to fertilise more frequently as well.

It’s important to understand the quality of your soil so that you can make better-informed decisions when it comes to choosing the right fertiliser. Therefore, before fertilising your lawn, it is recommended to you perform a soil pH test to find out your lawn’s soil quality.

The degree of soil pH acidity and alkalinity is measured on a scale of 0-14, with a pH of 7 neutral, 0-7 acidic, and 7-14 alkaline. Ideally, your soil should be neutral (around 6.5). If your soil is too acidic (below 6.5) add lime if it is too alkaline (above 7) add a sulphur-based product.

There are a few ways to test your soil pH.

Soil pH kits are a simple, cheap and effective way to get an idea of your soil pH. They come with easy-to-follow instructions and a colour chart that indicates the pH of your soil.

To get a more holistic idea of your lawn pH, take the soil from your lawn around 100mm deep in several spots in your garden. This will give you an idea of whether your pH changes across your lawn.

Professional soil tests are an alternative solution. You can expect to pay around $150 and upwards for a thorough analysis of your soil, however it will provide valuable information that will help determine what type of lawn fertiliser you should use and how often.

For a professional soil test, you will need to collect your own lawn soil sample by randomly pulling 10 to 12 individual soil samples from your lawn to a depth of about 100mm, before returning it to the lab for sampling.

Before fertilising, and while waiting for your soil test to come back, aerate, and rake your lawn to remove leaves and other debris.

If you decide to mow, allow at least two days before fertilising.

Once you fertilise your lawn – wait at least a week before mowing and when you mow for the first time leave the catcher off (this is so the fertiliser remains on the lawn).

Fertilising Lawn in Spring

Application of lawn fertiliser with extra nitrogen in spring will encourage new leaf growth, giving your lawn a nice green makeover after a cold winter.

Be careful not to fertilise too early in the season, as new growth is more susceptible to damage from frost. Once the risk of frost has passed, you can safely apply your fertiliser, and watch your lawn start to green up.

Fertilising Lawn in Summer

Fertilising your lawn in summer helps it to maintain an even growth pattern and gives it the correct balance of nutrients.

Avoid fertilising in the middle of summer as lawns are susceptible to burning. Instead, apply your fertiliser at the beginning and the end of the season (in December and late February) for best results.

Fertilising Lawn in Autumn and Winter

As the weather begins to cool and the days grow shorter, it’s important to give your lawn a little extra care to help it thrive throughout the winter months.

Fertilising in the autumn provides nutrients that promote prolonged growth and help the grass to develop deep roots. This results in a thicker, healthier lawn that is better able to withstand the cold weather of winter and maintain its colour.

Fertilising your garden is essential for a healthy lawn. Still, it is possible to make mistakes when applying fertiliser, which can lead to poor plant growth or even damage to the environment.

Over Fertilising your Lawn

Too much nitrogen can be harmful to plants, causing a condition known as fertiliser burn. When grasses are over fertilised, the roots experience less growth than the leaves, resulting in an imbalance. This can cause the leaves to turn yellow or brown, and the grass may appear stunted or sickly. In extreme cases, the roots may die, causing the grass to die off.

If you think your lawn may be over fertilised, look for signs such as discoloured leaves, darkened or weak roots, and a salt-like crust on the soil.

Erratic Fertilisation

For consistent and even results, your fertiliser should be distributed evenly.

If you’re using liquid fertiliser, apply it to your lawn using a sprayer with a wide nozzle, and use slow even strokes across the lawn. This will avoid having patches of uneven growth where the fertiliser has pooled.

If using a granular fertiliser, walk back and forth across the lawn with a spreader to ensure consistent application rates

Not Watering Regularly

Just like excessive fertilisation, insufficient water when you apply fertiliser can cause an imbalance, leading to grass burns and eventual lawn death.

Too Much Water

Overwatering your lawn after fertilising can undo the good work you’ve done by diluting your fertiliser or causing it to be washed past the roots before the plants can absorb it.

Overwatering can also encourage weeds, pests and diseases to take hold, so water lightly, but frequently to avoid waterlogging.

LawnPride Tracemaxx 5L Concentrate

LawnPride Maintain 26-2-9 + 3.4 Fe 20kg

LawnPride GroTurf 20kg 15-4-11 + Traces

Oxafert

Fertilising your lawn should be part of every homeowner’s regular lawn maintenance, providing much-needed nutrition for the health of your backyard. There are plenty of fertilisers to choose from, and which one you choose will depend on the type of grass you have, and the time of year you fertilise. Always commence your fertilisation program with a soil pH test to ensure that you are providing the right nutrition for your soils, and where possible, plan to fertilise your lawn three times a year for optimal results.

For a range of leading fertilisers for your lawn, visit myhomeTURF’s online store.