The Importance of fertilising in Autumn

Author: Stefan Palm   Date Posted: 11 March 2021 

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

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

The timing of your application in Autumn is important to consider. If you do it too early, your lawn will use most of the nutrient 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 nutrient from the soil. In a typical year, I'd recommend to get onto Autumn fertilising in mid April but this year has been a lot cooler than usual. Ground temperatures in Adelaide have significantly fallen over the last two weeks which means there is potential for lawns to start going into Winter dormancy earlier. With this in mind, I'd recommend that you get onto fertilising your lawn any time from now till the end of March.  

Why fertilise in Autumn?

Essentially speaking, Autumn fertilising prepares you lawn for Winter and Spring.  By applying a solid fertiliser now, you anchieve some important outcomes:  

  • While the lawn is still active, feeding will improve its colour and overall health now.
  • Your lawn will be stronger and healthier leading into Winter resulting in a greater ability to hold colour, especially through the cold months when couch, kikuyu and buffalo lawns tend to fade in their colour. Colour loss in Winter 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 mid autumn a perfect time to give your lawn what it’s looking for. But not just any fertiliser, preferably a mineral fertiliser (not organic) that’s high in potassium. 

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 a bunch of others. Some come from an organic source, others are of a mineral 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, 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 should you look 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)

Nitrogen is vital for a healthy lawn. In fact, your lawn won’t grow without it. However, too little available nitrogen not only leads to slow growth, it also 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 encourages good water uptake and strong cell and root formation that helps grass survive Winter temperatures.

Trace elements are a bonus and worth looking for as well. They are kind of like a multi-vitamin for your lawn! The fertiliser we recommend for Autumn is Paul Munn’s Emerald Green. It has exactly the right analysis you are looking for for Autumn fertilising and, applied at the right time will help your lawn to hold better colour and stand up to the rigours of Winter better.


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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