What does NPK mean

NPK is an interesting collection of letters that play a very important role in the health of your lawn. These 3 little letters appear on all fertiliser bags and are big factors in helping your lawn get the nutrients it needs. This week’s turf tip helps decipher just what NPK means.


A balanced diet

All living things require a balanced diet to ensure they get all the different nutrients they need. It is recommended that a balanced diet for us is a combination of protein, fruits, vegetables, grains and dairy. For your lawn, it is all about water and fertiliser.

And when it comes to fertiliser, not all fertilisers are created equal. But thanks to NPK it is easy to ensure the fertiliser you are using is giving your lawn the nutrients it needs. But what exactly do the letters NPK stand for? That’s simple, its percentage of Nitrogen, Phosphorus and Potassium your fertiliser contains. Here is what those elements mean for your lawn.


(N) – Nitrogen

The first element of NKP is nitrogen (N). One of the most important elements in organic chemistry, nitrogen is also one of the most important elements in lawn care. It will usually be the highest percentage of the NPK ratio of your fertiliser, but what does it do?

The simplest explanation of the role nitrogen plays in a healthy lawn is that it is responsible for growth above the ground. Largely responsible for the growth of leaves of a plant, nitrogen is what will have the biggest impact on what you see in your lawn.


(P) – Phosphorus

The second element of NPK is phosphorus (P). An essential plant nutrient, phosphorus is often the limiting nutrient (growth is limited by the least available nutrient). Early sources of phosphorus for plant nutrients included bone ash.

If Nitrogen is responsible for above the ground, it won’t surprise you to learn that phosphorus is responsible for below the ground in a balanced fertiliser. While often a very low percentage of the NPK ratio of your fertiliser, its role is just as vital as nitrogen. Phosphorus is responsible for root growth, and without a solid root structure, your grass cannot support healthy leaf growth. So while you may not physically see its effect on your lawn, its importance cannot be understated. Phosphorus moves very slowly through the soil which is why huge amounts aren’t needed.


(K) – Potassium

The last element of NPK is potassium (K). Vital for the functioning of all living cells, potassium is an important part of our own diet. It is also an essential component of plant nutrition making it equally important for a healthy lawn as a healthy you.

While nitrogen and phosphorus perform specific roles above or below ground, potassium is an all-rounder. It is the nutrient responsible for the overall functions of a plant, and therefore your lawn. Used for vigour and growth, potassium helps your lawn withstand drought and disease. It also helps your lawn use nitrogen more efficiently.


Which fertiliser for Sir Walter?

Our Lawn Solutions Australia Premium fertiliser which is available from our sales office has an NPK of 16-0.7-4. So that means there is 16% nitrogen, 0.7% phosphorous and 4% potassium. This is perfect for Sir Walter and is also suitable for all other varieties we sell. Next time you are buying fertiliser be sure to check the NPK and make sure you get the right mix for the results you are looking for.

Need to green up, make has lots of nitrogen. If you need better root growth make sure there is enough phosphorous. And if you need general vitality and health check the potassium content.



To get more advice on fertilising your lawn or to order a new lawn call our team on (07) 3114 8230. You can also to pop in and order in person at our sales office on 1/243 Bradman Street, Acacia Ridge. The office opens Monday to Friday 7am to 5pm and Saturday 7am to 12pm.

For more great turf, tips keep an eye on our website and all our social media channels.

Leave a Reply

Your email address will not be published. Required fields are marked *

45 Years

of experience in turf

Turf delivered

fresh from the farm

AusGAP Certified

ensures the genetic purity of our turf-grass varieties

100% Secure Checkout

PayPal / MasterCard / Visa

© Jimboomba Turf Group 2021