Although the weather is cooling, plants still have a few months growing time left so will benefit from a nutritional boost to see them through winter.
But, unlike a summer feed, which focuses on lush, green growth, an autumn fertiliser is designed to prepare your lawn for the challenging conditions of the colder months. This means you need to avoid using fertilisers designed to maximise growth and focus on the nutritional profile to ensure strong root development, and hardening the plant off to withstand the cooler weather and potential frosts.
Go Low On Nitrogen In Autumn
While some nitrogen is needed to help the grass prepare for winter, an excessive amount can be detrimental. Start by looking for a fertiliser that doesn’t have a high ratio of nitrogen to phosphate and potassium.
Why go easy on the nitrogen? If you apply too much nitrogen in autumn, it will stimulate a surge of soft lush growth. This is problematic because we need grass in autumn to shift its energy to developing roots.
If it uses that energy to produce too much new green blade growth, it can become vulnerable to damage from frost, and diseases that thrive in cooler months – like fusarium patch for example.
Key Nutrients in Autumn Fertiliser
In autumn, we are looking for a fertiliser that helps increase the resilience of your lawn grass so that it can survive winter and deliver healthy turf in spring.
Ideally, autumn lawn fertilisers will contain:
Nitrogen (N): Whilst we don’t want too much in an autumn fertiliser, we do need some to help maintain colour.
Potassium (K): The higher potassium content in autumn fertilisers helps to "harden" the grass blades and cells. This makes the lawn more resistant to fungal diseases like red thread and fusarium (also known as snow mould), which can cause unsightly brown patches.
Phosphorus (P): Phosphorous is crucial for promoting strong root development. A well-developed root system helps the grass withstand the stresses of cold temperatures, frost, and potential waterlogging during a typical British winter. This makes it more likely to survive and thrive when spring arrives.
Iron (Fe): Often included to provide a quick greening effect, iron can also help suppress moss. Autumn is the season when moss and weeds can take hold in a weakened lawn. By strengthening the grass with a fertiliser containing iron, you allow it to outcompete moss and weeds for water, nutrients, and sunlight - reducing the need for extensive moss control later on.
Magnesium (Mg): Aids in photosynthesis, helping the grass stay green during shorter, darker days.
Slow release or controlled release fertilisers can be beneficial in autumn, providing a steady, trickle-feed of nutrients over a period of time (typically 6-12 weeks). This ensures the lawn is continuously fed throughout autumn, without encouraging excessive growth.
Agrigem’s Top Three Autumn Lawn Fertilisers
A good allrounder for autumn is our Nutrigrow 3-12-12 autumn blend fertiliser. This will help strengthen turf and encourage strong root development – ideal for pre-winter months. The NPK (nitrogen, phosphate, potassium) analysis of this fertiliser is 3% nitrogen, 12% phosphate, and 12% potassium.
This particular fertiliser has versatile application rates- as low as 35g/m² enabling one bag to cover 600m² making for an economical product.
MossTop contains a good balance of nutrients together with a high level of iron which can blacken moss making it easier to remove. It is also a conventional-release formulation, so it will deliver nutrients to the grass over six weeks.
Autumn-gem is a fully foliar liquid fertiliser. Foliar fertilisers are more readily available to the plant when compared with granular fertilisers as they are absorbed through the leaf tissue rather than the root system - meaning results are usually seen much quicker. The NPK analysis of this fertiliser is: 4% nitrogen, 2% phosphate, 16% potassium.
We offer a range of autumn fertilisers and nutritional products that can be used to great effect in the cooler months. If you are unsure about which to choose, please get in touch with our technical team for free tailored advice.
