When to Fertilise Your Lawn (Australian Guide)

If you fertilise your lawn before the soil has had time to warm up, you’re basically just wasting your time and money.

If you want a nice lush green lawn that you can enjoy all summer long, you want to know when to fertilise it to get the best results. 

When is the best time to fertilise your lawn?

The absolute best time to fertilise your lawn is in spring. This is when the grass is coming out of its winter dormancy and will produce lots of new growth as the weather and the soil warms up.

If you only like to fertilise your lawn once a year, then you should definitely do it in spring.

For those people who don’t mind giving their lawn a feed twice a year, then the next best time to fertilise is in autumn. Fertilising your lawn again in autumn will give it a boost and prepare it well for winter.

This is especially important if you live in the southern parts of the country and experience the occasional frost.

What happens if you fertilise your lawn too early?

If you fertilise your lawn before the soil has had time to warm up, you’re basically just wasting your time and money.

This is because the grass is not ready yet to take up the nutrients from the fertiliser and with a few heavy showers of rain, it will be leached from the soil.

You should wait until the grass has started to actively grow and when the soil temperature is at least around 14 degrees Celsius. For most parts of the country, this usually happens around October.

How often should you fertilise your lawn?

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Grass can be fertilised a second time in autumn to prepare it for winter.

Ideally, for the absolute best results, you should fertilise your lawn twice a year. Once in spring as active growth commences and then again in autumn to prepare your lawn for winter.

This is especially the case if you’re using a granular or pelleted slow-release or controlled-release fertiliser that you spread over the lawn.

On the other hand, if you’re using a liquid fertiliser, this should be reapplied every 1 to 2 months as the nutrients are absorbed by the grass almost immediately after application.

However, if you’re trying to fix a lawn problem or your lawn has had some growing difficulties, you can apply a light application of fertiliser during summer to give it a little boost.

Make sure that you don’t overfertilise your lawn because this could have detrimental effects.

Another reason that you might want to fertilise your lawn over summer is if you want to green it up. In this case, it’s best to use a liquid lawn fertiliser so that you don’t end up burning the roots of the grass.

When should you not fertilise your lawn?

It’s not necessary to fertilise your lawn in winter because the grass will be dormant and fertilising will make no difference to either the colour or growth of your lawn.

When should you first fertilise a new lawn?

If you’ve just turfed a new lawn, wait for around six weeks and then fertilise it. Follow this with a good soaking. This will give your new lawn a great start and it should grow well.

On the other hand, if you’ve seeded a new lawn, you can apply a special starter fertiliser immediately and then apply a regular lawn fertiliser around 4 to 6 weeks after sowing the seed.

Should I fertilise before or after mowing?

Lawn mower 1 | Lawn care
You should wait at least a week or so before mowing your lawn after fertilising.

It’s best to fertilise your lawn around 2 days after mowing. This will expose the soil a little so that the fertiliser can work its way down into the ground where the roots can take up the nutrients.

Additionally, I generally like to wait at least a week or so before mowing again so that the fertiliser that you’ve applied doesn’t all end up in the catcher.

Do I fertilise before or after rain?

It’s generally recommended that you wait at least one day after rain to apply fertiliser to your lawn.

Make sure that the grass is completely dry before you apply the fertiliser.

It’s also not a good idea to fertilise just before a heavy rainfall because the fertiliser might simply just get washed away.

How do I make my grass dark green?

The best way to green up your lawn is to add a fertiliser that’s high in nitrogen.

This vital macronutrient stimulates the production of chlorophyll and this is what gives the grass its dark green colour.

You should be careful not to overfertilise though because this will burn the roots of the grass and turn it yellow instead.

Always follow the recommended quantities on the pack.

Other FAQ

Can you fertilise lawn in autumn?

Absolutely, apart from spring, autumn is the best time to fertilise your lawn because it will prepare it well for the cold weather in winter.

Can you fertilise lawn in winter?

You should not fertilise your lawn in winter because the grass is not actively growing and won’t take up the nutrients.

When is it too cold to fertilise a lawn?

When the soil temperature drops to below 14 degrees Celsius, the grass will stop growing and it would be a waste to fertilise at this time.

Why is my lawn turning yellow after fertilising?

Generally, this will happen if you’ve applied too much fertiliser. While nitrogen is essential for strong growth and a greener lawn, too much of it can burn the roots of the grass and this will result in the yellowing of the grass. To avoid this, apply only enough fertiliser to give the lawn a boost and always stick to the quantity recommended on the fertiliser pack.

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Annette Hird

Annette Hird is a gardening expert with many years of experience in a range of gardening related positions. She has an Associate Diploma of Applied Science in Horticulture and has worked in a variety of production nurseries, primarily as a propagator. She has also been responsible for a large homestead garden that included lawn care, fruit trees, roses and many other ornamental plants. More recently, Annette has concentrated on improving the garden landscape of the homes that she has lived in and focused a lot of energy on growing edible plants as well. She now enjoys sharing her experience and knowledge with others by writing articles about all facets of gardening and growing plants.


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