5 Best Winter Lawn Fertilisers of 2025

Proctors Autumn and Winter Lawn Feed helps out with two things that frequently cause problems in the garden during winter – grass that won’t grow, and moss that grows too much. It’s a tough balance!

It can be applied during both autumn and winter to help improve grass coverage without causing any undesired growth spurts. The slow-release fertiliser has a low nitrogen content, combined with a higher concentration of phosphorous and potassium; it thickens patchy lawns and creates a strong carpet of grass without wasting energy on excessive growth.

The fertiliser contains seaweed which is a natural source of phosphorous and known to assist with soil aeration – improving drainage and avoiding problems associated with damp soil. In turn this improves the strength of roots, and the health of grass.

Coming in a 20 kg bag, you get plenty of fertiliser for quite a reasonable price – especially considering that it should be applied at a rate of 35 g/m². When applied carefully, one bag can cover an area of approximately 570 m² (for reference: a standard tennis court is 261 m²).

The granules are a reasonably uniform size, which helps achieve an even distribution when using a spreader – they don’t clog the machine. Unlike some fertilisers, this product doesn’t scorch the grass either, which is likely thanks to how easy it is to evenly apply.

It does need to be well watered to see good effects though.

Unfortunately, despite this fertiliser’s iron content, it’s a bit hit and miss when it comes to attacking moss. Some customers have reported a large amount of moss being killed off by the product, whilst others haven’t had as much success. When used to treat moss, it needs to be applied at a higher concentration – 50 g/m².

This is one of the best winter lawn fertilisers overall, thanks to how effectively it can help grass grow over winter. It can also be used up to every six weeks throughout the year, so there’s no need for any to go to waste.

When it comes to garden care, Miracle-Gro have been creating reliable products for over 150  years; their EverGreen Autumn Lawn Care is a basic yet effective fertiliser that also offers good value for money.

One 12.6 kg bag covers approximately 360 m² (when applied at a rate of 35 g/m²), which is plenty of product for most standard gardens (if you’d like a more accurate reference – 360 m² is about the same size as twenty parking spaces!).

This is a reasonably quick-working fertiliser, with results visible in as little as one week. It has an NPK ratio of 6-5-10 which results in a lawn that grows thicker, and achieves better coverage, without having a growth spurt.

It should ideally be applied between September and November, with a maximum of two applications per year.

If you have bare patches on the grass, and it’s coming up to winter, this is a good product to use to fill in the spaces and get a more even, balanced lawn without waiting until spring to fix the problem.

It’s best applied with a rotary spreader – a drop spreader can result in uneven application which may in turn cause burnt patches to appear on the lawn.

One thing to note: if there’s no rain forecast, you’ll need to make sure to fully water in the fertiliser yourself. It takes a while, and a fair amount of water, for the granules to dissolve.

This is one of the most reliable winter fertilisers, and it’s the best winter lawn fertiliser if you’re looking for value for money as well. As long as it is applied evenly, it’s a great option for filling in patchy, sparse areas of grass.

There are two types of Proctors Autumn/Winter fertiliser on this page, each with slightly different properties, suitable for different types of lawn. This particular Autumn and Winter Lawn Feed has an NPK ratio of 3-10-5 meaning it’s very high in phosphorous and slightly more balanced when it comes to nitrogen and potassium.

This is especially useful if the soil in your garden is naturally lacking in phosphorous; phosphorous helps improve root growth and strength.

Proctor’s Autumn and Winter Lawn Feed can be spread from September onwards and makes a visible difference to the density and quality of the grass in this time. Approximately three applications across winter seems to work well. If your lawn is looking tired and patchy as winter moves in, this is one of the best winter lawn fertilisers to achieve a much healthier looking lawn come springtime.

The fertiliser consists of relatively fine granules, so it can be a case of trial-and-error to make sure that they are applied at the recommended amount of 35 g/m². If you are using a spreader that is intended for larger granules, you will need to reduce the aperture accordingly.

When applied correctly, the 20 kg bag can cover an area of approximately 570 m².

Although you may not use such a large bag over one winter, the fertiliser can be kept for the following year as well. It needs to be kept well sealed in a cool, dry space.

A final thing of note about this product is the packaging – unlike a lot of brands that don’t seem to put much thought into their plastic packaging, Proctors have used a bag that is designed to biodegrade. It contains recycled plastic, and materials from renewable sources.

Helping to protect grass health over the winter months, The Grass People Slow Release Autumn/Winter Fertiliser is designed to combat the damaging effects of disease and frost. The aim is to preserve the appearance of the lawn until spring (or whenever the weather actually starts to warm up; we all know how unpredictable our UK climate can be!).

With an NPK ratio of 8-0-6, this is a low-phosphorous, high-nitrogen/potassium formula. Potassium is useful in autumn to improve the strength and resilience of plants, whilst nitrogen is more commonly used in spring to help with growth and the lush green appearance of the grass.

Together, these result in a product that can be used several times over autumn and winter to prepare grass in different ways for spring.

Whilst 0% phosphorous might seem unusual, some gardeners prefer to avoid fertilisers containing phosphorous to avoid excessive use. Too much phosphorous in the soil can cause problems.

The overall effect of this fertiliser is grass that grows in thicker and greener. You just need to make sure it is applied during times when the grass is still growing – if the temperatures drop too much, and the grass goes dormant, the fertiliser will make no difference.

It comes as a 20 kg bag and should be applied at a density of 35 g/m². This is best achieved using a spreader, rather than attempting to get the measurements right by hand. At this application rate, one bag will cover approximately 570 m².

According to the manufacturer, once opened, the fertiliser can be kept for up to four years as long as it is kept sealed in a cool, dry space. For this reason, and because of its nitrogen and potassium content, this is one of the best winter lawn seeds to keep and use during any time of year. In winter, the potassium will help improve grass strength, and in the growing season the nitrogen will boost growth and health.

If you have a smaller garden, or are working on a tighter budget, the Substral Winter Fit Fertiliser is a cheaper alternative to the other products on this page.

Sold in a 2 kg box, this granular fertiliser covers an area of approximately 100 m². The instructions state that should generally be applied at a density of 20 g/m². For areas that need more attention, this can be increased up to 30 g/m².

It contains nitrogen and potassium, helping grass to stay resilient and strong over winter. In particular, potassium is useful to help grass withstand the damaging effects of frost and disease over the colder months.

This product is best suited to being applied towards the end of summer and during autumn to give grass the strength to endure winter. It can also help repair damage after a harsh summer, with the nitrogen encouraging grass to grow following any drought or excessive trampling.

According to Substral, the slow-release granules stay active for approximately 100 days, meaning they are constantly adding nutrients to the soil.

Overall, it’s one of the best winter lawn fertilisers to buy on a budget. You get a generous amount of product for the price, and it will be sufficient to cover the majority of small/medium gardens.

You may need a second box if you are covering a larger area, or applying the fertiliser using the higher concentration. Nevertheless, it will probably still work out cheaper than buying other products, which is great if that’s what you’re looking for.