The Importance of fertilising in Autumn

Author: Stefan Palm   Date Posted: 4 April 2024 

How important is Autumn fertilising for lawns? Very important! In this blog, I'll talk about why and I'll also explain why it's important get the timing right.

​With summer being so dry this year, there is a fair chance your lawn may be looking a little worse for wear. Fertilising in Autumn is always a good idea; however, it's even more important this season. 

Why fertilise in Autumn?

Essentially speaking, Autumn fertilising prepares your lawn for Winter and Spring.  By applying a granular fertiliser now (rather than a liquid), you achieve some essential outcomes:  

  • While the lawn is still active, feeding now will improve its colour and overall health.
  • Your lawn will be stronger and healthier coming into Winter, resulting in a greater ability to hold colour, especially through the cold months when couch, kikuyu and buffalo lawns tend to fade. Colour loss in Winter to some degree is inevitable for these types of lawns; however, it won't be as severe with an application of Autumn fertiliser. 
  • Having absorbed this nutrient, your lawn will travel through Winter and have 'something left in the tank', so to speak, come Spring. When ambient and ground temperatures increase, your lawn will come out of dormancy and get going faster.

That makes autumn a perfect time to give your lawn what it’s looking for. But not just any fertiliser, preferably a mineral fertiliser (not organic) high in potassium, such as Paul Munns Emerald Green which has been especially developed for Autumn fertilising.  

What's in a fertiliser?

Almost all fertilisers have three main ingredients those being nitrogen (N), phosphorous (P) and potassium (K). Some go one step further and contain other components, such as trace elements. These include things like iron, zinc, copper, boron, and many others. Some come from an organic source, others are of a mineral or chemical origin. This means the contents of most fertilisers are different, and so is the amount of each element they contain. For example, some contain higher levels of nitrogen or more potassium than others. Some have trace elements, and some don’t. That doesn’t necessarily mean that some products are better than others. They are simply different and designed for different purposes.

What are you looking for in an Autumn Fertiliser?

On the back of every fertiliser bag, there is a small table showing you what’s in the fertiliser and how much of each element it contains. This is called the fertiliser analysis. An ideal analysis for an Autumn fertiliser looks like this:

Nitrogen (N): 12 to 18%

Nitrogen is vital for a healthy lawn. Your lawn won’t grow without it. However, too little available nitrogen leads to slow growth and increases the likelihood of some diseases, as well as yellowing of blades and thinning of turf. This results in increased weed pressure.

Phosphorous (P): At least 4%

Phosphorus assists in converting the sun’s energy and other elements, such as nitrogen, into usable food for lawns. Phosphorous also makes lawns more vigorous.

Potassium (K): At least 6% (9% is ideal)

Potassium encourages Winter hardiness.  Potassium promotes good water uptake and strong cell and root formation that helps grass survive Winter temperatures.

The fertiliser we recommend for Autumn is Paul Munn’s Emerald Green. It has precisely the correct analysis you are looking for and, applied at the right time, will help your lawn hold better colour and stand up to the rigours of Winter better.

Why is it important to get the timing of your Autumn fertiliser right?

The timing of your application in Autumn is important to consider. Typically, if you do it too early in the Autumn, your lawn will use most of the nutrients before it gets to Winter, which isn't ideal. If you do it too late on warm-season grasses like Couch, Kikuyu and Buffalo, your lawn will have gone into Winter dormancy and won't be able to absorb nutrients from the soil. 

Usually, I'd recommend getting onto Autumn fertilising in mid- to late April however, this year has been a lot dryer than usual. Given that this may have resulted in your lawn taking a hit, it may need some time to repair before Winter.  To take advantage of the lingering warm weather, I'd recommend that you fertilise now.  This will give your lawn time to take all that goodness in and do some repairing work before the cool weather sets in. 

How to fertilise properly

I know it's not rocket science, and I'm guessing most people have done it before however, this year is a little different. Given that the ground has been so dry, it will, in many cases, become water-repellent. Have a read of my blog on water repellency in soil to understand more about this. Water repellency is a significant factor in why lawns can look so poor in hot, dry weather. Since water is the carrier of the nutrients down to the root zone, I would strongly recommend applying a liquid wetting agent before you apply the fertiliser this year. It will ensure you get deep penetration of water and nutrients. This equals better results from your fertiliser and a faster response from your lawn.  

  1. Water your lawn first
  2. Apply a liquid wetting agent 
  3. Apply your fertiliser directly after the wetting agent
  4. Water both in together immediately with around 25mm of water. You'll need to give it a really good soak to wash the wetter and fertiliser deep down into your soil. You shouldn't be able to see any fertiliser on the surface when you have finished watering. 

It's best to do this in the cool part of the day - ideally morning.   If you have any questions or comments, you can drop a comment below or send us an email to

Comments (5)

New Lawn Fertilizer

By: on 12 March 2021
Should I fertilize our new lawn (planted late Feb) this Autumn? It is Sir Walter Buffalo, what type of fertilizer would I use Christine Jones

Paul Munns Instant Lawn Response
Hi Christine Thanks for your query. Being as the lawn is new I would suggest using an organic lawn fertiliser now. In Spring you can use a stronger fertiliser

Should I fertilise the lawn before, during, or aft

By: on 1 May 2019
Should I fertilise the lawn before, during, or after a good rain in autumn?

Paul Munns Instant Lawn Response
Hey Magdalene, You can fertilise before a decent rain but you need to make sure that you get enough rain to water it completely into your lawn. If you can still see fertiliser after the rain, you will need to finish watering it in by hand/sprinklers.

Spring/summer lawn fertilizer

By: on 12 April 2019
Great article! Is the fertiliser recommended for Autumn - Paul Munn’s Emerald Green, also suitable for spring & Summer?

Paul Munns Instant Lawn Response
Hey Tania, Emerald Green can be used throughout the year but it was developed as an Autumn time fertiliser. We recommend Paul Munns Green Keeper for Spring and Paul Munns Organic Lawn Food for Summer.

Early fertilising?

By: on 12 April 2019
Hi, I fertilised my Kikuyu lawn in mid March using Emerald Green. Was this too early? Should I do a small "top up" now? Thanks

Paul Munns Instant Lawn Response
Hey Stephen, If you fertilised in mid March, then you would not need to do a top up now. The best time is early to mid April so you're not too far off the mark. Nice job using the Emerald Green - we recon its the best for Autumn fertilising

Emerald green fertiliser

By: on 25 April 2018
Is emerald green ok for buffalo and sir Walter? Thank you Susan Patterson

Paul Munns Instant Lawn Response
Hi Susan, Yes - Emerald Green is an excellent autumn fertiliser for buffalo lawns like Sir Walter. Its high potassium level will give your lawn an extra level of hardiness and colour retention over winter.

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