Lawn fertiliser, feeding & nutrition

A lawn that receives the correct amount of nutrition not only looks healthy but is more tolerant to common turf problems.

The results of a healthy lawn include good colour, more wear tolerance, good disease resistance, excellent weed suppression and good root development, resulting in improved drought resistance.

There are many nutrients that the grass plant requires but there are 3 key nutrients that most lawn and turf areas require to remain healthy.

The 3 nutrients that a lawn fertiliser should contain are Nitrogen (N), Phosphates (P) and Potash (K), all three being essential for a healthy and vigorous lawn. It is these nutrients that we shall cover on this page. We shall look at the role and their importance to the grass plant of these nutrients in a little more detail.

• Nitrogen (N): Nitrogen is important for plant growth and it gives the leaf it's deep green colour. It is the most important of the 3 main nutrients in a lawn fertiliser as it is readily used up by the plant and is leached through the soil more than the others. Used in the spring when the temperature rises, it helps to kick-start and maintain growth going into summer. It should not be used in large quantities during the autumn and winter months as it could lead to a fungal disease attack, particularly fusarium patch disease. Fusarium can be quite severe in the winter so it is essential not to apply large quantities of nitrogen later than late August / early September.
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• Phosphates (P): The main reason for applying phosphates is to produce a healthy and vigorous root system. This encourages earlier growth come spring time resulting in a healthier lawn in the summertime. Although it is more readily available than nitrogen within the root zone it may still be beneficial to apply once a season.
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• Potash (K): The main role of potash is to harden the plant, helps make the plant less susceptible to drought and helps with plant metabolism. Potash is important during the autumn and winter months as it helps with disease resistance.

What fertiliser to use & when to apply

The first lawn fertiliser application of the year will be at the start of spring. This is when the temperatures are starting to rise and the grass is starting to finally show some growth, after the cold winter months. This application should be a nitrogen based fertiliser with additional phosphates and potash.

There are different types of fertiliser on the market, for example: you may want to use a slow release fertiliser. These are generally more expensive than conventional fertilisers, the advantages being that you get slower, more consistent growth with greater longevity.

Alternatively you can use a conventional fertiliser where you will tend to get very quick growth and less longevity. Depending on the fertiliser used in spring a further application may be necessary during the summer months.

Heading into the winter months your fertiliser program should be Phosphate and Potash based to harden up the plant for winter. Very little nitrogen should be applied during this period as this can lead to disease problems.

It is important to choose the correct weather conditions for fertiliser application. If you are applying a granular feed it will be best applied during periods of showery weather. Make sure that the foliage is dry when you apply your feed. If no rain falls after application make sure it is watered in thoroughly to prevent scorch.

Liquid fertilisers may need a different approach depending on whether you are using a foliar feed or root feed. Whatever you choose it is important to follow the manufacturers instructions.

Methods of fertiliser application

Which ever method you use it is important to try and get an even distribution to prevent scorching or missed areas.
The main application methods are as follows:

• Hand Application: This is probably the most commonly used method of fertiliser application, however the main problem with this method is uneven application. The correct way to apply, is to apply half the rate going up and down the lawn. Apply half the rate again using the same method by going cross ways, 90 degrees from the first pass.
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• Hand Held Applicator: There are two types of hand applicator the first has a spreader nozzle that fixes on to the container holding the fertiliser. The second type is a hopper that is hand held and a handle is then turned and the fertiliser is distributed via a spinner onto the lawn.
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• Liquid Application: Some fertilisers are soluble, or in a liquid form therefore require a liquid applicator. There are many types available including a watering can, knapsack sprayer or a hose end applicator.
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• Wheeled Distribution: There are two types of wheeled applicators (see pictures below). A spinner type spreader which as it's name suggests spins out the fertiliser and is ideal for large areas as it covers a large area quickly. The other type is a drop spreader which is slower than a spinner type but when used correctly is a very accurate method of application.

A drop fertiliser spreader	A spinner fertiliser spreader