Fertilising your lawn

Fertilising your lawn

When fertilising your lawn you need to remember to use the right mixture, quantity and apply at the right time of the year. A common lawn care mistake is to fertilise heavily in Spring with the expectation of seeing a plush, green lawn emerge.

Most commercial fertilisers contain soluble nitrogen, which in too large a quantity will burn your lawn. Too much fertiliser can also encourage extra lawn maintenance, will leave your lawn more prone to disease, insect damage and will waste time, money and energy for no extra reward.

How much should I use?


The answer is to follow the manufactures recommendations/directions closely. What you want is to encourage the top growth without endangering the root growth. Fertilisers generally contain 3 major ingredients: Nitrogen (N), Phosphorous (P), and Potassium (K) along with some other minor nutrients.

You will find three numbers on a fertiliser bucket which represent the mix of these major ingredients by percentage. The numbers will appear in the N, P, K order. You will also be able to see the guaranteed analysis of the fertiliser on the bucket.

Grass needs more Nitrogen than other nutrients due to its being an essential part of the chlorophyll molecule. This is what causes your lawn to get that deep green colour you want to have. However, Nitrogen will cause top growth at the expense of root growth.

Phosphorus is needed in the energy transfer system of the plant and is needed in a lesser quantity than the other two nutrients in an already established lawn. It is however very essential to a newly planted lawn.

Finally, Potassium helps to make your lawn insect and disease resistant and aids in cell wall development.

Learn more about NPK: What does NPK mean

Choose a slow-release mix

LSA Fert

When looking at a fertiliser you should look for a slow-release nitrogen mix. There are two types of nitrogen generally found in most fertilisers, these are organic and non-organic.

Ammonium nitrate and ammonium sulphate are the most commonly used non-organic sources. These are both very soluble which makes them more quickly available to your lawn which will cause quick growth and greening over a short period. It is, however, becoming more common for turf-masters to recommend a slow-release organic, nitrogen mix.

The most common forms that these take are sulphur coated urea, I.B.D.U., urea-formaldehyde, resin-coated urea, methylene urea and natural organics. Using these will produce a good colour without sacrificing root growth and because they are slow-release, will require less frequent application. The general recommendation of turf experts is to use a fertiliser that has at least half of its nitrogen mix in a slow-release form.

An established lawn of either Cool Season or Warm Season grasses will do well with a 3-1-2 or 4-1-2 mix of N, P, K. Among the analysis numbers that fit that ratio, you will find: 12-4-8, 15-5-10, 16-4-8, 21-7-14 and 20-5-10.

We thoroughly recommend a slow-release fertiliser such as Lawn Solutions Premium Lawn Fertiliser which has a great balance of 16-0.7-4.

Watering in


After the application of fertiliser, make sure to remove any excess fertiliser from hard surfaces to avoid staining them.

It’s essential to have a watering in process, once you have applied your slow-release fertiliser. It is vital that you water in your fertiliser so it avoids burning your lawn. You will have a schedule a watering program post-application. Most fertilisers will need to be watered in, if you are uncertain read the label or check with the manufacturer.

You can water in your fertiliser with a sprinkler and hose or time it before rain. Be careful when applying before rain as too much can wash fertiliser out of your lawn.

Read the Label

When determining how much to use, first look at the recommended rates on the bucket. You want to apply the correct amount evenly on your lawn to achieve good growth. Over fertilisation will cause excessive leaf growth and weaken your lawn.

For more advice on fertilising your lawn call our team on (07) 3114 8281. You can also to pop in and order in person at our sales office on 1/243 Bradman Street, Acacia Ridge. The office opens Monday to Friday 7am to 5pm and Saturday 7am to 12pm.

For more great lawn care tips keep an eye on our website and all our social media channels.

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