The Fertiliser Guide

After all, a wise man once said, ‘good lawn management calls for a regular lawn feeding programme’. We couldn’t agree more with Dr D.G.Hessayon, who said this exact sentence in the gardener’s unofficial bible – The Lawn Expert.

In this ultimate fertiliser guide, we will cover everything you need to know about fertiliser; from the best fertiliser to apply to your garden, how to apply and when.

For some background knowledge on what fertiliser actually is, you may want to read our blog, Fertiliser: What is it?, to help give you a better understanding of fertiliser breakdowns and how it benefits your garden.

Another useful blog to explore before feeding your lawn is how to keep pets safe when using fertiliser as this is one of our most commonly asked questions!

What are the essential nutrients in fertiliser

The three nutrients that any lawn needs are Nitrogen, Phosphate and Potassium – also known as the acronym NPK (each letter represents the nutrient element initial). These nutrients all serve varying purposes and are very useful when combined to make a compound fertiliser.

• Nitrogen (N) is responsible for giving the lawn its lush green colour by stimulating leaf growth and helping to establish the lawn.
• Phosphate (P) is known for building up the root system and improving seed-to-soil contact.
• Potassium (K) can help to harden grass so that it builds up immunity/tolerance to disease and drought.

Look out for these when researching fertiliser. You will find that fertilisers designed for new seedlings will have high levels of Phosphate or fertilisers for use in spring/summer will have a higher Nitrogen concentration compared to those designed for autumn/winter. A high concentration of Nitrogen is useful in a Spring/Summer fertiliser, it won’t be in an Autumn/Winter fertiliser when you hope to give the mower a much-needed break!

When should I use fertiliser

Ideally, you will want to apply fertiliser on a year-round schedule in order to keep your grass green and healthy season after season! Look out for season-specific fertilisers to give your grass the optimal nutrients for its needs at that time of year. 

Best time to fertilise a lawn

• Spring/Summer – Encourages faster grass growth, greener grass and better wear & tear recovery.
• Autumn/Winter - Prepares and strengthens the lawn against winter diseases and cooler conditions.
• Winter - Moss prevention and protection against frost and freezing temperatures.

Types of fertilisers

There are two types of fertilisers – liquid and granular. Below, we have broken down the benefits of each to help you decide on what's right for your lawn and project:

Liquid fertilisers:

• Instant results
• Nutrients are instantly available to the grass
• It is ideal for lawns needing a quick boost of nutrients
• It is quick to apply and doesn't require watering in
• You can buy it in smaller quantities
• Conveniently packaged for easy storage
• Easy to use, requiring only a watering can

Granular fertilisers:

• Easy to see while applying
• The slow-releasing variant needs to be applied less frequently throughout the year
• Ready to use
• Easy to scatter across your lawn using a spreader or by hand
• A slow-release feed with 12-16-week coverage
• Quick-release feed boost with 4-6-week coverage

Quick-release and slow-release granular fertilisers

An example of the NPK level of our QUICK RELEASE: Spring / Summer granular fertiliser is 9.7.7. This shows that the Nitrogen concentration is slightly higher than the Phosphate and Potassium. This encourages fast growth and greener grass with the added bonus of a strengthened root system and protection against drought. As there isn’t much difference between the levels of each nutrient – you could consider this fertiliser as a bit of an ‘all-rounder’ to kick start the spring season. 

An example of a slightly different NPK level to this would be our SLOW RELEASE: Spring / Summer fertiliser is a granular fertiliser that has an NPK of 12.6.6. You can tell that the concentration of Nitrogen is double that of the Phosphate and Potassium concentrate. This means that it will help your grass grow greener and stimulate leaf growth over a longer period of time in comparison to our Quick Release. But it will also slowly build up your lawn's root system and tolerance against drought, disease and discolouration.

Best conditions for applying fertiliser

The ideal conditions for applying any kind of fertiliser is when the soil is moist. This creates the best environment for the fertiliser to be absorbed into the soil and roots of the grass. A great time to apply fertiliser with moist soil conditions is after it has been raining!

It is advisable to avoid fertiliser application during prolonged periods of dry weather. If you are planning to apply fertiliser during drier conditions, hose down the lawn before application and give it a helping hand by keeping the soil moist whilst the granules dissolve.

NOTE: You don’t need to “water in” liquid fertiliser!

Top tips for applying fertiliser

There are four main ways to apply fertiliser to a lawn, and this is where the type of fertiliser does matter. Be aware that no one should apply liquid fertiliser with their bare hands!

The four main ways are:

• Hand Application – used for granular fertiliser to scatter across the lawn.
• Hand-Held Distributor – there are two types on the market – one that requires you to wind the handle to distribute granular fertiliser and another that has a nozzle to allow you to spread the liquid fertiliser.
• Liquid Dilutor – this is for liquid fertiliser that is spread through a hose.
• Wheeled Distributor – This one requires quite a bit of skill and is for granular fertiliser. If completed correctly, you should be able to cover the lawn thoroughly.

There are pros and cons to each method. Ultimately, you should choose the easiest application method for you, which suits the fertiliser product you intend to use and will provide full coverage without the risk of scorching and/or double-dosing your lawn.

For further reading, we have helpful fertiliser guides below:

• What is fertiliser?
• What fertiliser should I use?
• When to feed my lawn?
• Choosing our liquid lawn fertiliser