Have you ever wondered about a lawn fertiliser is and how it works?
Follow our easy five-step guide outlining all you need to know about lawn fertilisers including:
1. What makes a lawn fertiliser the best for lawns
2. The different types of lawn fertilisers
3. How to apply lawn fertilisers
4. When to apply lawn fertiliser
5. Seasonal recommendations
The sight of a lush, green, well-manicured lawn is something to behold, complementing your home and garden. To accomplish a great lawn, you need the appropriate lawn variety for your climate, reliable water, good mowing practice and, importantly, the right blend of nutrients.
Lawns grow vigorously through the warmer months when they use a lot of energy that’s fuelled by plenty of nutrients. This is the main reason for fertilising. Regular feeding with a good quality lawn food will support this growth keeping your lawn healthy and looking great.
As a general rule, start at the beginning of spring and feed every 4-6 weeks until mid/late autumn, but the frequency can vary depending on what type of fertiliser you use and your soil type. Sandy soils are less nutritious and leach water and nutrients far more quickly than clay soils, so more frequent applications are generally needed.
Step 1 – What makes a lawn fertiliser the best for lawns?
Lawn fertilisers are specifically designed to provide a range of essential nutrients for optimum lawn growth. The nutrients they contain differ slightly from a regular plant fertiliser because lawn grasses grow differently from a flowering plant. For example, lawn foods have higher concentrations of nitrogen to boost lawn growth and colour but lower concentrations of potassium, which is normally in fertilisers as it promotes flowering and fruiting, but this is not relevant for lawns.
Top three nutrients
The main three elements found in lawn fertilisers are nitrogen, phosphorous and potassium. These are combined with other macro and trace elements in various forms for healthy lawn growth.
Nitrogen (N) Provides lush, green leaf and stem growth and has a high percentage in lawn fertilisers.
Phosphorous (P) Helps develop strong roots, turf establishment and overall health.
Potassium (K) Helps build strong cells, improves disease resistance and improves tolerance to stress from heat, cold, drought, wear and tear.
Other macro and trace elements
Calcium (Ca) Builds strong cell walls and wall integrity. It maintains the soils pH and improves overall nutrient availability.
Iron (Fe) Helps grass to photosynthesize to green up the lawn.
Sulphur (S) Lowers soil alkalinity and brings its pH toward the acidic range. It also helps to ‘unlock’ iron and makes it available to the plant.
Magnesium (Mg) Important for winter hardiness and overall healthy growth. It balances soil pH so the lawn doesn’t become too acidic.
Zinc (Zn) Helps to regulate metabolic activity and, combined with other elements, allows the production of chlorophyll.
Manganese (Mn) Helps with nitrogen uptake, enzyme activation and photosynthesis. It also helps protect against diseases and aids chlorophyll formation.
As well as these elements, you will find boron and copper plus additional health and growth stimulants such as organic components and beneficial microbes for soil improvements.
Step 2 – The different types of lawn fertilisers
There are many different types of lawn fertilisers that deliver nutrients in different ways. There is no right or wrong choice, as what is chosen depends on how often you want to apply fertilisers and which type you prefer. Many people may use a combination of different types of lawn fertilisers throughout the growing season,
1. Granular lawn fertilisers
These are made up of synthetic granules and usually contain a balance of nitrogen, phosphorous and potassium as well as a blend of trace elements for overall health and vigour.
2. Slow-release lawn fertilisers
Granular or pelletised fertilisers that release nutrients in a slow or controlled manner gradually feeding lawns over time as opposed to a big dump of nutrients in one hit. Slow release also means nutrients are released at a rate at which they can be used by the lawn, so they don’t get flushed through the soil, sometimes ending up as pollutants in waterways.
3. Organic lawn fertilisers
Made from natural organic materials such as manures and composts, organic fertilisers are often combined with other materials including seaweed and beneficial soil microbes. They may be in granular, pelletised or liquid form.
Seasol Lawn + Soil Booster is an example of an organic fertiliser that packs a lot in for your lawn and soil. It’s a natural pelletised complete lawn health treatment with a rich source of seaweed and compost to boost soil health and lush, green growth in all lawns including buffalo.
Generally, apply every 10-12 weeks or as needed. Apply 100 grams of Seasol Lawn + Soil Booster per square metre to established lawns. Ensure even distribution via hand or lawn spreader. Water it in thoroughly after application.
For new lawns or turf apply 100 grams of Seasol Lawn + Soil Booster per square metre into the soil prior to seeding or laying turf. For best results apply an application of Seasol Lawn & Turf Starter or Seasol the Seaweed solution every 7 – 10 days while establishing.
4. Dynamic fertilisers
These are fertilisers that combine slow and quick release nutrients and sometimes also include organic fertilisers and conditioners such as compost and seaweed. This combination gives lawns a quick boost for fast results as well as a longer-term feed. They can also improve soil with compost and in some cases include beneficial soil microbes. These are the ultimate lawn foods.
PowerFeed LawnFeed andPowerFeed Buffalo LawnFeed with Troforte technology are examples of dynamic fertilisers. They deliver a balanced blend of slow and quick release of nutrients to all lawns including buffalo. Boosted with seaweed and beneficial microbes, they boost lawn health and growth and improve the soil structure, helping lawns to access nutrients within the soil.
PowerFeed LawnFeed or PowerFeed Buffalo LawnFeed can be used at any time of the year depending on the variety of lawn. Generally, one application at the start of spring, summer and autumn is recommended. During the growing season, best practice is to apply every 4-6 weeks.
Apply 20-30g of PowerFeed LawnFeed or PowerFeed Buffalo LawnFeed per square metre to established lawns. Ensure even distribution via hand or lawn spreader. Water in thoroughly after application and sweep any excess off paths or driveways.
For best results do not apply to newly laid lawn turf or seed, apply an application of Seasol Lawn & Turf Starter or Seasol the Seaweed solution every 7 – 10 days while establishing your new lawn.
5. Liquid fertilisers
These are very fast acting as they get taken up through the roots and leaves to give fast results. They come in ready-to-use hose-on bottles and in concentrate form to dilute with water in a sprayer pack or watering can.
As the liquid provides nutrients to the lawn quickly, they can correct nutrient deficiencies to boost healthy growth and create a lush, green lawn. They are also ideal to be used straight after mowing to reduce foliar stress to the cut leaf and help improve their resistance to environmental stresses such as heat, drought, frost and foot traffic.
Liquid fertilisers release their nutrients rapidly and therefore are usually applied more often than granular or pelletised formulations. Typically, they are applied to the lawn fortnightly to monthly during the growing period (spring to autumn).
They are a quick and easy way to feed lawn grasses and can contain a blend of essential nutrients as well as liquid composts and seaweed.
Seasol for Lush Green Lawns or Seasol for Buffalo Lawns are tried and tested favourites among liquid fertilisers that gives fast and excellent results. Both are superior health treatment and fertilisers that are safe to use on all lawns including buffalo.
They combine the benefits of Seasol with a specially formulated nutrient mix, trace elements, concentrated liquid composts and a wetting agent to feed and revitalise all lawns. It promotes healthy, green growth, stronger root systems and increases tolerance to heat, drought, frost and foot traffic.
Both contains highly active liquid compost and a wetting agent to improve the soil health. They condition the soil to increase soil friability and reduce nutrient leeching and soil moisture retention.
Application is easy: simply attach it to your hose. Each container treats up to 100 square metres of lawn.
6. Lawn Starters
For newly laid turf lawns or lawns started from seed, a lawn starter assists establishment and early growth. These products come in granular and liquid form and are highly recommended as an easy way to help ensure a good start to a new lawn.
Granular forms are usually slow release and are added to the soil before the turf goes down or applied with the lawn seed. They work within the soil and lawn for up to 12 weeks.
A liquid form is usually applied after the turf has been laid or the seed sown and are applied every week for the first six weeks.
Seasol Lawn & Turf Starter is an excellent example of a lawn starter to get your lawn off to a great start. It contains Seasol, plus highly active liquid compost to improve seed germination rates and reduce transplant shock on lawn turf.
It promotes strong root development, healthy green growth and reduces stress from heat, drought, frost and foot traffic. Boosted with highly active liquid compost it helps to improve soil health, moisture retention and nutrient uptake.
TIP Ensure your newly sown seed or new turf is kept moist at all times. Long, deep watering ensures that the roots grow down into the soil.
Step 3 – How to apply lawn fertilisers
All fertilisers come with instructions and application rates that need to be followed carefully. Over fertilising can result in burning your lawn, while excess fertilisers also leach into waterways, which damages the environment.
Most granular fertilisers, including dynamic ones, need to be watered in immediately after application to avoid burning the lawn. Watering in also activates the fertiliser and, in the case of Powerfeed LawnFeed, the beneficial soil microbes.
Applying when it’s about to rain or even when it is raining saves time and water. An even coverage gives a balanced, even feed and growth. Spreading by hand is okay but using a fertiliser spreader ensures even application. Spreaders are available as small, handheld units or as larger units on wheels. Spreaders can be adjusted to vary the amount of fertiliser being delivered.
Pelletised, organic fertilisers generally require more volume than synthetic, granular or dynamic fertilisers, 100g per square metre for example is a fairly standard application rate. Otherwise the same application principles above apply for pelletised fertilisers. Ensure even coverage for even growth. Sweep any excess pellets off hard surfaces such as paving and driveways to avoid staining. Water in well after application or apply during rain to save time and water.
Most liquid fertilisers come in a hose-on bottle to click onto the hose. To apply, turn the tap to medium pressure then spray onto the lawn. They are quick and easy to use and can be reused many times. To re-use, fill up with 1 part concentrate and 3 parts water or as directed on the bottle.
If required, hose-on can be diluted for watering can use at the rate of 80 mL per 9L of water. Regular fortnightly or monthly applications promotes a healthy, lush, green lawn. Hose-on products should not be used if it is raining or rain is imminent and always wash off any surfaces to avoid possible staining.
Step 4 – When to apply lawn fertiliser
Fertilisers are designed to provide the necessary nutrients to support lawn growth throughout the growing season from spring to autumn. So, it makes sense to apply from the beginning of spring and continue until mid-late autumn to keep the lawn in top condition.
How much fertilising is needed largely depends on soil quality and the nutrients it contains that are readily available for the lawn. Fast-draining sandy soils for example leach water and nutrients very quickly so sandy soils need regular watering and fertilising. The trick is to get the balance right to avoid wasting water and fertiliser.
Over doing fertiliser applications means excess fertiliser leaches through the soil into waterways, which is a waste of money and bad for the environment. It is better to lower the application rate slightly but increase frequency.
If you’re blessed with the perfect loam your lawn will still benefit from the tailored nutrients found in high quality dynamic fertilisers like PowerFeed LawnFeed with the big three nitrogen, phosphorous and potassium plus trace elements, beneficial microbes and added seaweed. By all means experiment a little to see what works best to get a high-performance lawn that’s the envy of your neighbour.
Step 5 – Seasonal recommendations.
At the beginning of spring use a dynamic fertiliser such as Powerfeed LawnFeed and water in. Alternatively use Seasol Lawn + Soil Booster for more soil-based improvements and a dynamic fertiliser to really get things moving. Follow this up with Seasol and/or PowerFeed liquid feeds every two weeks.
As things heat up, your lawn is subject to more stress from heat. Warm-season grasses such as buffalo, couch, kikuyu and zoysia, will be growing at their optimum levels. Cool-season lawn grasses such as fescue and ryegrasses, need additional water to keep them growing through summer. Lawn growth benefits from extra nutrients so keep the fertilising rates up to the spring regime. Applying Seasol helps alleviate the environmental stresses experienced by lawns during summer.
Continue the feeding program into autumn. A good feed late in the season gives lawns a boost prior to winter when warm-season lawns go into varying states of dormancy. Feeding cool-season grasses at this time helps to boost their growth into winter.
During winter, when lawns are dormant, regularly apply Seasol to maintain a strong immune system and healthy soil