What Fertiliser Should I Use This Spring On My Lawn?
As the days lengthen and the temperature starts to rise, spring is the perfect time to give your lawn the nutrients it needs to thrive. Choosing the right fertiliser is crucial to ensuring your grass stays healthy and green throughout the season.
1. Understanding the Nutrient Needs of Your Lawn
Before purchasing fertiliser, it's essential to understand the key nutrients your lawn requires. These include:
- Nitrogen (N): The most important nutrient for healthy grass growth, nitrogen helps your lawn develop its lovely green blades. It is crucial for photosynthesis and overall plant health.
- Phosphorus (P): This nutrient supports strong root development, which is vital for establishing deep, healthy roots. Many soils already contain sufficient phosphorus, so it’s typically not necessary to add more unless you’re sowing new grass or have a specific soil deficiency.
- Potassium (K): Potassium strengthens your lawn’s immune system, making it more resistant to diseases, pests and drought. It also helps your grass withstand temperature fluctuations.
Lawn fertilisers typically come in a ratio of these nutrients (e.g., 20-10-10), with the first number representing nitrogen, the second phosphorus and the third potassium. Understanding these ratios will help you choose the best option for your lawn.
2. Soil Test: The Key to Customised Fertilisation
One of the most effective ways to determine the best fertiliser for your lawn is by conducting a soil test. A soil test will tell you the pH level of your soil and its nutrient composition. This information allows you to select a fertiliser that addresses any deficiencies in your soil. There is no point in purchasing a Nitrogen rich fertiliser for example if your lawn is already full of it.
If your soil test reveals an imbalance, you can choose a fertiliser with the appropriate nutrient ratios to correct any deficiencies. For example, if your soil is low in phosphorus, look for a fertiliser with a higher middle number (e.g., 20-10-10), or if your soil has a pH imbalance, you may need to amend it with lime or sulphur before fertilising.
3. Choosing the Right Fertiliser for Spring
When choosing a fertiliser for spring, it’s essential to select one that gives your lawn a good start without overwhelming it. Here are a few options to consider:
Organic Fertilisers
Organic fertilisers, such as compost or manure-based products, are great for feeding your lawn gradually while improving soil structure over time. They release nutrients slowly, ensuring your grass receives consistent nourishment without the risk of “burning” the grass. Organic fertilisers also promote soil health by encouraging beneficial microbial activity and improving water retention.
If you prefer an organic option, look for slow-release nitrogen fertilisers like blood meal, fish meal , chicken manure, seaweed or alfalfa meal. These can be excellent choices for a natural lawn care regimen.
Synthetic Fertilisers
Synthetic fertilisers, while effective for providing quick nutrients, tend to release their nutrients rapidly, leading to faster grass growth. They are an excellent choice if you’re looking for a quick boost to get your lawn green and thick in spring.
Look for a fertiliser with a balanced nutrient ratio for spring, such as a 20-5-10 or 24-5-10 formula. These are usually high in nitrogen to encourage vigorous grass growth. Slow-release synthetic fertilisers are also a good option if you want a controlled, steady release of nutrients throughout the growing season.
Pre-Emergent Fertiliser
If you're looking to combat weeds while feeding your lawn, a pre-emergent fertiliser could be the right choice. Pre-emergent fertilisers contain herbicides that prevent weed seeds from germinating such as crabgrass and dandelions while providing the necessary nutrients for your grass to grow strong. However, use pre-emergent fertilisers with caution as they can prevent desirable grass seed from germinating as well. Only apply them if you're not planning to overseed your lawn in the spring.
4. When to Apply Fertiliser in Spring
Timing is key when it comes to fertilising your lawn in spring. Applying fertiliser too early can cause nutrient runoff especially if your lawn is still dormant while applying too late can stunt growth or allow weeds to take hold.
For most lawns, the best time to fertilise is once the soil temperature reaches around 10-12°C (50-55°F) and grass begins to show signs of new growth—typically in early to mid-spring. This ensures that the fertiliser will be absorbed efficiently by the grass, and you’re not wasting nutrients.
It’s also important to avoid fertilising when there’s a heavy rainfall forecasted. Heavy rain can wash away the fertiliser before your lawn has a chance to absorb it. Make sure there are no frosts around also!
5. How to Apply Fertiliser Properly
When applying fertiliser, always follow the manufacturer’s instructions to avoid over-fertilisation, which can lead to burn spots or excessive growth. You can use a broadcast spreader for even application- we would advise against a drop spreader. Be sure to water your lawn thoroughly after fertilising to help the nutrients penetrate the soil.
If you’re using a granular fertiliser, be careful not to apply it during windy conditions to avoid uneven coverage. If you’re using a liquid fertiliser apply it when your lawn isn’t stressed by extreme heat.
6. Keep an Eye on Your Lawn
After fertilising, monitor your lawn’s progress. If the grass begins to turn yellow or show signs of stress you may need to adjust your fertilisation routine. Similarly, if the lawn is growing too quickly or looking excessively lush, you might want to cut back on the nitrogen levels in future fertilisations.