Fertilising your lawn in Autumn
Author: Stefan Palm Date Posted: 6 March 2016
All lawns should be fertilised three times per year for optimal colour, hardiness and health. The best times are mid spring, mid summer and mid autumn. Being autumn, it’s a good time to consider what to use now and why it’s very important to fertilise the lawn before winter.
To answer the first question, almost all fertilisers have three main ingredients, nitrogen (N), phosphorous (P) and potassium (K). Some go one step further and contain other components called 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. It‘s more like they are different and designed for different purposes. So what does your lawn need during autumn? We know the main grasses (couch, kikuyu and buffalo) will soon begin preparing for winter dormancy. They do this by storing enough energy during the latter part of autumn to get them through winter and still have ‘something left in the tank’ so to speak, to start growing again in spring. A lawn correctly fertilised in autumn is also more likely to hold its green colour through winter.
That makes autumn a perfect time to give your lawn what it’s looking for by way of fertiliser. But not just any fertiliser, preferably a mineral fertiliser (not organic) that’s strong and punchy. The best time to apply this is mid April. 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 a lawn during autumn looks like this:
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, especially in warm-season grasses that go into winter dormancy. Potassium encourages good water uptake and strong cell and root formation that helps grass survive winter temperatures.
Trace elements are a bonus but 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 winter colour and stand up to the rigours of winter temperature extremes.