When it comes to your lawn, you’re a proud parent. You might’ve watched it grow up from when it was just a little seed. You might’ve adopted it in from somewhere else, and watched it spread its runners throughout your backyard.

You were there when it germinated, and when it properly established itself after its first good soaking. You’ve seen it mature into the beautiful lawn you have today.

Like any proud parent, you want to ensure that now that your lawn is all grown-up, big and strong, it stays big and strong. And there’s no better way to do that than by treating it to a good meal.

Top-dressing your lawn with a good fertiliser can be an important part of your lawn maintenance routine, particularly if the soil and conditions aren’t as good as they could be for your beloved turf. Fertiliser can replace nutrients that are vital to your lawn’s survival, which may be otherwise missing from the soil.

Once you know the preferred make-up of the fertiliser that your lawn will enjoy, there’s one last question to answer – which is the best lawn fertiliser for me – a quick acting or a slow release?

As with anything, there are pros and cons that come with each choice. Let’s have a look at the differences between the two, so that you can better understand the situations in which to use them.

Quick Acting Fertilisers

Quick acting fertilisers are the athlete’s Red Bull, or diabetic’s gummy bears of the lawn world. They are often used as a quick fix, but that is not necessarily a bad thing.

Quick acting fertilisers dissolve on contact with water, and are available in a variety of forms, from liquid and crystal, to powder and granule. Common quick acting fertilisers include ammonium nitrate and potassium chloride.


  • Quick acting fertilisers give a struggling lawn a quick and hefty kick along. They pack a nutrient punch that will have your lawn looking great in next to no time.
  • Their dissolvability means that you can either get them working by spreading the fertiliser before a good rain, or watering them in as soon as they are spread. This gives you total control over when your lawn gets the extra nutrients.


  • Like a firework, quick acting fertiliser follow their explosive start with a quick burn-out time. The nutrients are usually either absorbed by the grass or washed away by water within just a week or two.
  • If you’re not careful to evenly spread your quick acting fertiliser, you may find that it burns some of your grass when it dissolves. The concentration of the nutrients can be hazardous to plants if it’s not evenly spread.

Slow Release Fertilisers

At the other end of the scale, slow release fertilisers provide a longer burning nutrient supply, albeit with less of a punch than that of quick acting.

It’s important to know that there are two types of slow release fertilisers – natural and artificial. Natural is made up of slow breakdown organic material (such as that found in blood and bone), while artificial is more often than not a chemical fertiliser, which has been made slow release by way of an artificial coating that is added to the fertiliser to delay its breakdown.


  • Slow release fertiliser essentially drip feeds your lawn, giving it a measured amount of nutrients every day, instead of all at once. This means that your lawn won’t be on a nutrient rollercoaster ride.
  • Slow release doesn’t need to be watered in – you can just set it and forget it
  • Because it lasts longer than quick acting, slow release fertiliser doesn’t have to be re-spread very often. For some lawns, you’ll only need a couple of doses a year!


  • If your lawn is on its last legs, slow release won’t provide that defibrillator effect that you may need. You need to be careful that you don’t allow your lawn to be too far gone before treating it with slow release.
  • Because of its slow acting nature, it can be hard to judge the effects of slow release fertiliser. You find yourself questioning whether you put on too much or too little until it starts to take effect.

As always, if you have any questions on fertiliser selection, consult the friendly team at McKays.


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