Lawn fertiliser guide to help your grass flourish

Give your garden a boost with the best lawn fertilisers to feed your grass.

Man standing with rake looking at lawn

by Natalie Corner |
Updated on

If your grass is lacking in colour and looking a bit pale, it's likely the soil needs feeding with lawn fertiliser. While you can opt to spread grass seeds if you want to fill in those unsightly bare patches, lawn fertiliser encourages growth where grass just simply needs reviving, making it look thick and lustrous once more.

Employing the help of fertiliser will help your grass stay strong, keep its colour and continue to grow. The crucial thing here is knowing exactly what lawn fertiliser to use that will give you a lawn with lasting health, and that won’t be environmentally destructive.

Best lawn fertiliser at a glance:

• Best overall fertiliser: Miracle-Gro Evergreen Complete 4 in 1 Lawn Food - View now on Amazon UK
Best liquid lawn fertiliser: envii Seafeed Xtra - Organic Liquid Seaweed Fertiliser - View now on Amazon UK
Best organic lawn fertiliser: Just Grow 'DUO' 5KG Organic Fertiliser - View now on Amazon UK
Best pet-safe lawn fertiliser: Westland 20400352 SafeLawn Child and Pet Friendly Natural Lawn Feed - View now on Amazon UK

It’s not just about attending to the nutritional demands of your lawn, you need to care for the microorganisms and overall soil health, too. In a forest, this happens naturally when dead flora and fauna break down, but in a tidy garden, that doesn’t happen.

That’s why we’ve created this guide to help you choose effective, sustainable fertilisers for your lawn. Please scroll down for fertiliser FAQs, including what NPK is, when and how to fertilise your lawn and fertiliser alternatives.

The best lawn fertilisers for your garden UK

Best liquid lawn fertiliser

Envii Seafeed Xtra
Price: £31.99


SeaFeed Xtra is a premium, organic seaweed fertiliser that promotes strong, lush growth for plants


  • Versatile and strengthening
  • Plant-based and organic
  • Anti-stress compounds


  • Large containers are awkward to use - decanting is recommended

Best organic lawn fertiliser

Just Grow DUO Double Organic Fertiliser - 5kg
Price: £16.99


This is a combination of seaweed and chicken manure. The seaweed acts as a supplement in improving


  • Organic and versatile
  • Super strength with double fertiliser
  • Perfect for fruit and veg


  • Chicken manure may smell

Best natural lawn fertiliser

Supreme Green
Price: £9.95


This concentrated liquid feed is based on seaweed extract derived from sustainably harvested kelp,


  • Suitable for all lawns
  • With plant development
  • Extra iron and kelp for greening


  • Takes a while - but worth the wait

Best pet-safe lawn fertiliser


Rrp: £10.49

Price: £9.30


Westland SafeLawn is a child and pet-friendly natural lawn feed that contains 100 per cent natural


  • Only natural ingredients
  • Improves soil fertility
  • Transforms organic matter into nutrients


  • Children and pets need not be excluded from treated areas

Best rated lawn fertiliser

Miracle-Gro Evergreen Complete 4 in 1 Lawn Food

Rrp: £26.40

Price: £24.40


This is top-rated on Amazon for a reason. With over 13,000 reviews of an average of 4.4 stars,


  • All-in-one for fertilising and killing
  • Good value and highly rated
  • Versatile and effective


  • Needs to be ideal conditions for the application
  • Wear protective gloves when sprinkling
  • Keep away from children, pets and water sources

Lawn fertiliser FAQs:

What are the types of lawn fertiliser?

Synthetic formulas - Chemical fertilisers that offer immediate release and quick greening of the lawn, but at the expense of long-term soil health. These are manufactured using fossil fuels. They tend to be cheaper.

Organic formulas - Naturally made from once-living organisms or their by-products. These are not as fast-acting as synthetics, they release their nutrients more slowly. This is better for your garden's long-term health if used properly.

Other aspects to consider are:

Granular fertilisers - A popular choice due to the ease of application.

Liquid or water-soluble fertilisers - Spread using a hose, providing a quick and effective way to introduce nutrients rapidly to the grassroots.

When is the best time to fertilise my lawn?

It's recommended to fertilise your lawn twice a year, between late March and April, in the early summer, and once more in late autumn. For best results, apply fertilisers when the soil is moist, or when rain is expected.

How to fertilise the lawn

Your lawn will get the most benefit from a fertiliser when you've just mown the grass. By feeding the newly shorn lawn with fertiliser, it will give the grass more time to absorb the nutrients before the next mow. If you mow your lawn after fertilising, you may disrupt the fertiliser before it has a chance to sink in properly.

You should not fertilise dry turf – there should be moisture in the soil for the grass plants to be able to take in the nutrients.

How you apply the fertiliser product will likely depend on the product's individual instructions, but for the most part, you can use a watering can for liquid fertiliser or spread it by hand if you are using granules.

Some lawn fertilisers may come with spreaders to make it easier to get an even distribution of feed across your lawn. You can also buy spreaders separately.

Should I water after fertilising?

Yes, always water your lawn before and after fertilising - or wait until it is due to rain.

What is NPK?

NPK stands for nitrogen (N) phosphorus (P) and potassium (K). When you buy a commercial fertiliser, you will see an analysis of the NPK content on the packaging.

You will generally see an NPK ratio on the label such as 7:4:7, for example. This is the product's percentage of nitrogen, phosphorus, and potassium. These ratios vary from product to product, but as a rule, you want to avoid anything with high percentages. This is often reserved for cheap synthetic products that offer a quick fix.

What are alternatives to fertiliser?

There are alternatives to packets of fertiliser if you want more natural ingredients:

Chicken manure is great for encouraging bugs and worms in the soil. It smells a bit, so best to apply it in cooler weather and when damp.

Grass mulch is great for helping retain the ground's moisture and encourage worms. If your lawnmower has a mulcher already then that's even better because it's free. But just be wary that it can encourage more weeds.

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Natalie Corner is the Commercial Content Editor across the Specialist Portfolio for Bauer Media and is slowly learning how to care for her plant babies. When she's not soaking up the three days of sunshine in the great British outdoors, she's testing out the latest BBQ products.

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