By now, the shift in weather signals has been quite noticeable. And for your lawn, these changes are critical. It’s your sign for autumn fertilisation. For business owners managing golf courses, public parks, or private green spaces—and for homeowners invested in vibrant lawns—autumn fertilisation is the cornerstone of preparing grass for the colder months ahead. In this guide, we explore the science, strategies, and benefits of autumn and winter lawn care, with a focus on selecting the right winter lawn fertiliser to strengthen root systems, enhance leaf colour, and suppress weeds. Ready to give your grass a boost? Let’s start growing!

Why Autumn Fertilisation Matters

For many grass varieties, autumn marks the transition from active growth to dormancy. Such is the case for warm-season species like couch and buffalo which slow down as soil temperatures drop. Regardless of turf type, however, autumn fertilising provides the nutrients needed to sustain grass through winter’s challenges. This includes frost, reduced sunlight, and competition from broadleaf weeds.

A well-timed winter fertiliser application in late March or early April ensures roots get enough essential nutrients, and store them to support cell function and resilience when growth slows. This not only improves leaf colour during the cooler months but also prepares lawns for vigorous regrowth in spring.

The Role of Winter Lawn Fertiliser

The best winter lawn fertiliser is formulated to address the unique demands of colder conditions. Unlike quick-release fertilisers that risk leaching or triggering sudden and excessive growths vulnerable to frost, slow-release fertilisers deliver nutrients at a slower rate, matching the grass’s reduced metabolic activity. These products typically contain higher potassium levels to strengthen cell walls and iron to maintain a rich green hue without excessive top growth. So when picking fertilisers, what should you be looking for?

The key ingredients to prioritise in winter grass fertiliser include:

Nitrogen (N): A light application supports root development without forcing leafy growth.
Potassium (K): Enhances drought and cold tolerance.
Iron (Fe): Improves leaf colour, countering winter yellowness.
Zoystar: A balanced fertiliser suitable for specific turf varieties, Zoystar supports root establishment without an excessively high nitrogen content—ideal for young or recovering turf in winter.

A fair warning: be careful not to use fertilisers with high-nitrogen content. Excessive nitrogen can cause plants to grow too quickly in the fall, resulting in tender, immature growth that is more vulnerable to freezing temperatures and winter damage or winterkill. Plants with excessive fall growth are also more susceptible to disease infection. Moreover, excess nitrogen can sometimes inhibit root development, which is crucial for plant survival during the winter. For best results, opt for a complete fertiliser with balanced ratios, such as 10-5-10 (N-P-K), supplemented with iron.

Can You Fertilise Grass in Winter?

A common question among turf managers is, “Can you fertilise grass in winter?” The answer depends on different factors such as grass type, regional climate, and soil conditions. In warmer northern regions, where soil temperatures remain above 10°C, light applications of winter fertiliser may still benefit warm-season grasses. In southern states, cool-season varieties actively absorb nutrients until soil temperatures drop below 5°C. Basically, the answer is yes, but of course with care.

Remember, fertilising grass in winter requires precision. Most winter fertilisers are designed specifically for cooler months, releasing nutrients gradually to align with the grass’s slower rate of uptake. In contrast, over-application or using the wrong fertiliser types (e.g., high-nitrogen quick-release formulas, as mentioned above) can weaken turf by depleting energy reserves. Again, encouraging tender growth prone to frost damage.

Choosing the Best Winter Lawn Fertiliser

Selecting the right product involves understanding your turf’s needs and local conditions. Here are some options and when are they ideal for use this season:

Slow-Release Fertilisers
Ideal for most lawns, these formulations minimise nutrient loss and provide steady nourishment over 8–12 weeks. Look for coatings like polymer or sulphur, which break down as soil temperatures rise. Zoystar is a great example—its balanced formula supports winter turf health without delivering excessive nitrogen, making it ideal for root development and recovery.
Liquid Fertilisers
Liquid or foliar fertiliser applications offer rapid absorption, useful for addressing poor health or nutrient deficiencies. However, they require careful dosing to avoid leaf burn in frost-prone areas.
Organic Fertilisers
Compost-based or seaweed extracts improve soil structure and microbial activity, fostering long-term plant health. While slower-acting, they reduce chemical runoff—a priority for eco-conscious spaces.
Pre-Emergent Herbicides
Some winter lawn fertilisers include pre-emergent herbicides to suppress broadleaf weeds and invasive grasses. These are particularly valuable for maintaining pristine surfaces on golf courses or parks.

Whichever you think would be best for your lawn and location, always remember that experts and professionals will be more than happy to assist you. Fertilisers are complex tools. But it does not mean you have to figure them out on your own.

Timing and Application Tips

To maximise the benefits of winter lawn fertilising, scheduling and application play a crucial role:

Target Late Autumn: Apply fertiliser in late March to early April, while soil temperatures remain mild enough for root activity.
Monitor Soil Temperatures: Use a soil thermometer to gauge nutrient uptake potential. Below 10°C, grass absorbs nutrients at a slower rate.
Adjust for Shaded Areas: Turf under trees or structures may require tailored treatments due to reduced sunlight and airflow.
Water Lightly: After application, irrigate lightly to activate granules without waterlogging soil.

Avoid mowing immediately before or after fertilising. Instead, lower the lawn mower blades gradually to maintain a slightly longer leaf length (2–3 cm), which shields roots from frost.

Common Mistakes to Avoid

Over-Fertilising: Excess nitrogen weakens grass, leaving it susceptible to cold damage. Stick to light applications.
Ignoring Soil Health: Compacted or acidic soil limits nutrient absorption. Conduct a soil test every 2–3 years.
Neglecting Spring Prep: Winter fertilising complements—not replaces—correct year-round fertilising. Plan spring treatments to capitalise on autumn groundwork.

Winter Lawn Care Beyond Fertilisers

A holistic lawn care regime ensures turf survives winter in peak condition. Fetilisers are great supplements for lush lawns all year round but keeping a solid routine on lawn care should always be your primary concern. So don’t forget the following tips on top of fertilising:

Aerate Compacted Soil: Improve drainage and oxygen flow to roots, particularly in high-traffic zones.
Control Weeds: Tackle broadleaf weeds in autumn to prevent them from monopolising nutrients.
Reduce Thatch: A thin thatch layer insulates roots, but excess buildup invites pests and disease.
Adjust Watering: As evaporation slows, reduce irrigation frequency but ensure deep soil hydration before frosts.

For added tips, watch this short video on preparing your lawn for winter. If you want to know more about what it takes to establish good quality turf, click here for more advice from our experts.

The Long-Term Benefits of Winter Fertilising

Investing in autumn and winter lawn care will definitely be worth it beyond the colder months. Healthier turf emerges in spring with deeper roots, uniform colour, and fewer weeds. For commercial spaces, this translates to lower maintenance costs and year-round visual appeal. Homeowners enjoy a resilient lawn capable of withstanding summer heat and drought.

By prioritising slow-release fertilisers, tailored applications, and soil health, you equip grass to thrive in every season.

Autumn fertilisation is not merely a task—it’s a strategic step toward sustainable turf management. Whether maintaining a sprawling golf course or a suburban garden, understanding the interplay between fertiliser types, soil temperatures, and grass physiology ensures your lawn remains robust, green, and ready for whatever the weather brings.

For further guidance on selecting the best winter lawn fertiliser for your needs, consult with a local lawn care expert or explore our range of professional-grade solutions designed for Australian conditions.