Your neighbour's lawn is always greener and nicer than yours? Maybe it's because your lawn is not getting enough nutrients. Therefore, you should consider fertilising your lawn more often. A good lawn fertiliser is an essential factor for your lawn to grow extra green and healthy.
If you are thinking about getting a good lawn fertiliser for your garden, you should read through our lawn fertiliser test 2021.
Here we introduce you to different types of fertiliser and explain all the advantages and disadvantages. It is important that you find the lawn fertiliser that is most suitable for you. However, our buying criteria should make your decision a lot easier.
- 1 Weekly newsletter with the best personal finance tips
- 2 Summary
- 3 The Best Lawn Fertiliser: Our Choices
- 4 Guide: Questions you should ask yourself before buying lawn fertiliser
- 5 Decision: What types of lawn fertiliser are there and which is the right one for you?
- 6 Buying criteria: Use these factors to compare and evaluate lawn fertilisers
- 7 Facts worth knowing about lawn fertiliser
- 7.1 At what time should I fertilise my lawn?
- 7.2 How do I apply the lawn fertiliser correctly?
- 7.3 How much lawn fertiliser should I use?
- 7.4 How do I dispose of lawn fertiliser correctly?
- 7.5 How do I store lawn fertiliser correctly and what is the shelf life of lawn fertiliser?
- 7.6 What can I do if I have used too much lawn fertiliser?
- 7.7 What is a burnt lawn?
- Fertilising the lawn is an important part of lawn care. As lawns are permanent crops, they need an external supply of nutrients, which you can easily provide in the form of lawn fertiliser.
- Depending on how the lawn is used, you should fertilise it two to three times a year.
- To avoid damage to your lawn, always follow the instructions on the lawn fertiliser package and calculate the correct amount of fertiliser for your lawn before use. You can find specific information on this below in our trivia section.
The Best Lawn Fertiliser: Our Choices
Guide: Questions you should ask yourself before buying lawn fertiliser
Why should I fertilise my lawn?
Regular mowing of the lawn forces it to grow back, for which it needs certain nutrients. However, these are partially removed with the clippings each time the lawn is mowed, so that the natural nutrient supply is not sufficient.
Lawns need constant maintenance because the grasses depend on a continuous supply of nutrients from outside in order to grow. First and foremost, lawn care also includes fertilising. If the lawn lacks important nutrients, fewer grasses will grow back. A decrease in green colour is also the result.
When should I fertilise my lawn?
The first time at the beginning of the warm vegetation period in spring and then a second time in summer, if necessary. To ensure that the lawn survives the winter well, it is recommended to fertilise again at the end of the vegetation period in autumn.
In addition, you should wait at least two days before mowing the lawn again so that some of the nutrients are not directly removed with the cuttings.
What nutrients does my lawn need?
Therefore, fertilisers containing mainly slow-acting forms of nitrogen should be preferred so that the lawn, as a permanent crop, is evenly supplied with the important nutrient.
Normal fertiliser used in agriculture and nurseries is not suitable for lawns because it contains an unsuitable combination of nutrients. Therefore, lawns need a special lawn fertiliser.
Is lawn fertiliser toxic for children or pets?
|Lawn fertiliser||How toxic?|
|Slow-release mineral fertiliser||About as toxic as table salt. After a vigorous watering or the next lawn cut, the lawn can be played on without hesitation.|
|Organic lawn fertiliser||After correct application directly playable without danger. Avoid cheap fertilisers that contain castor bean meal. The ricin it contains is toxic if it has not been sufficiently heated before further processing.|
|Lawn fertiliser with weed killer||it is best to water the lawn before application to speed up the effect. After one or two days, the lawn should be thoroughly watered again. Only after the weed killer has taken effect can the lawn be walked on again.|
|Lawn fertiliser with moss killer||Ideally, apply the fertiliser to a damp, freshly mown lawn so that the moss killer reaches the moss quickly. You can water the lawn after two days at the earliest, mow it after another two days and remove the dead moss from the turf. Due to the active ingredient iron-II-sulphate, which can have a corrosive effect, children and animals should not come into contact with freshly treated lawns. After thorough watering, the lawn can be walked on again.|
What does NPK stand for?
- Nitrogen (N)
- Phosphorus (P)
- Potassium (K)
How much does lawn fertiliser cost?
For this reason, it is advisable to compare products per square metre and according to recommended frequency of application. Another factor is whether the lawn fertiliser is a pure lawn fertiliser or a combination product with a weed killer.
What are the alternatives to lawn fertiliser?
Plant Aid 3 A86
An alternative to the classic lawn fertiliser in granulated or liquid form is the plant aid 3 A86, which is obtained from marine algae. For the production of the powder, three types of seaweed from the sea are gently dried, mixed and ground to a microfine size. The universally applicable plant fortifier contains 86 ingredients and works in three ways:
- The mineral salts focus and diffuse sunlight.
- The leaves warm up and produce more chlorophyll.
- The vital substances enrich the metabolism.
Root formation and metabolism are sustainably strengthened, which boosts growth. Unlike other fertilisers, it contains various micronutrients, minerals and trace elements as well as vitamins and enzymes, lanthanides and growth stimulants that positively promote the entire soil life.
You can use the natural fertiliser for any plants in your garden, as long as they do not require a low pH value, and it is best applied by spraying. You treat your lawn - as with the usual lawn fertilisers - two to three times a year with the plant aid by dissolving one teaspoon of powder in ten litres of water.
You can buy the plant strengthener both as a powder and in liquid form, one litre at a time.
Blue grain is a chemically produced complete fertiliser that is available in granulated and liquid form. It belongs to the group of complex fertilisers, the exact composition of which varies depending on the manufacturer, and can be used for all garden and pot plants.
If you want to use blue grain as a fertiliser for your lawn, you should be very careful with the fertiliser to avoid burning the lawn. Between March and October is the right time to apply the granulate to the lawn by hand (with gloves!).
Follow the instructions on the packaging carefully. In contrast to the plant aid 3 A86, Blaukorn is not suitable for lawns that are regularly played on by children or pets.
Coffee grounds contain valuable substances such as phosphorus, potassium and nitrogen. Coffee is also slightly acidic, which lowers the pH of the soil. However, you should spread the coffee grounds over a large area and then sprinkle the lawn.
Decision: What types of lawn fertiliser are there and which is the right one for you?
Basically, you can distinguish between two different types of lawn fertiliser:
- Organic lawn fertiliser
- Mineral lawn fertiliser
Both types offer different advantages and disadvantages, which are mainly determined by the intended use. Depending on which nutrients are too much or too little present in the soil and what the respective lawn needs in particular, either mineral fertiliser, organic fertiliser or even a mixture of both types is best suited.
In the following section we will compare the advantages and disadvantages of the two fertilisers.
What distinguishes organic lawn fertiliser and what are its advantages and disadvantages?
In organic fertilisers, the fertilising elements are contained in carbon-containing reduced compounds. The fertiliser is of animal or plant origin, such as compost or manure.
Organic lawn fertilisers are released in the soil depending on the weather - moisture and warmth - which is why they are an easy way to supply the soil with nutrients evenly and adequately, especially in the long term.
Organic fertiliser works more slowly because it must first be decomposed by microorganisms and animals in order to release its nutrients into the soil. This is both an advantage and a disadvantage, depending on what is needed at the time. This prevents possible overfertilisation, which can easily happen with mineral fertilisers.
Another advantage of organic fertiliser over mineral fertiliser is the improvement and enrichment of humus and soil quality.
A definite disadvantage of organic fertiliser is its dependence on soil warmth, as the microorganisms become active depending on the temperature and therefore, for example, more nutrients are released in autumn than in spring.
What distinguishes mineral lawn fertiliser and what are its advantages and disadvantages?
Mineral lawn fertilisers require expert use, among other things, due to their fast mode of action, and are therefore increasingly used by garden centres and less by private individuals.
In the case of mineral fertilisers, the fertilising elements mostly exist in the form of salts, which are either extracted through mining or produced in costly energy-intensive chemical processes. The introduction of mineral fertilisers was a major productivity advance in agriculture and mineral fertilisers are still widely used today.
The idea is that the salts are suspended when they come into contact with water and can thus be absorbed by the plant. One disadvantage is that the fertiliser can easily be washed into the groundwater during heavy rainfall and thus the plants do not receive any nutrients.
Toxic metals and other pollutants can also enter the drinking water and the food chain. Mineral fertiliser is therefore best used as a supplement when certain nutrients are lacking in the soil.
In addition, the sustainability aspect must also be considered, as phosphorus deposits are running out and the quantities of natural gas used in production are also a problem.
There is also a combination of both types of fertiliser: the mineral-organic fertiliser.
Mineral-organic lawn fertiliser
Mineral-organic lawn fertilisers combine the advantages of organic and mineral fertilisers so that a good supply of nutrients is ensured and the soil quality and soil life are protected at the same time.
Organic lawn fertiliser
Another option that you can fertilise with is organic lawn fertiliser. This has similar properties to organic mineral fertiliser, but only contains the mineral components permitted in organic farming.
The organic content of organic lawn fertiliser is also very high, which shows that resources are being used sustainably. Basically, lawn fertilisers can also be divided into two categories with regard to their mode of action:
- Long-term fertiliser
- Short-term fertiliser
Long-term lawn fertiliser slowly releases nutrients into the soil over a period of three to six months, while short-term fertiliser is only effective for a very short time. Since this fertiliser is quickly soluble, the lawn is immediately supplied with nutrients.
However, it must be re-fertilised regularly because this effect does not last. If you use short-term mineral fertiliser, the risk of overdosing and "burning" the lawn is particularly high.
You can also differentiate between fertilisers according to the application period. You can find more information about this in our trivia section below.
Of course, you can also buy combination products that are multifunctional and with which you can not only fertilise your lawn but also kill moss and weeds at the same time.
Buying criteria: Use these factors to compare and evaluate lawn fertilisers
Here we help you compare lawn fertilisers and find the right one for you. The following criteria have proven to be useful in assessing which lawn fertiliser is best for you:
- Time of application
- Toxicity / environmental friendliness
- Duration of effect
- Nitrogen content
- Phosphorus content
- Potassium content
- Weedkiller additive
In the following paragraphs you can read about the individual purchase criteria and how you can classify them. Depending on the lawn, however, there can be considerable differences in nitrogen, phosphorus and potassium. To find the perfect fertiliser, you should have your soil tested for nutrients.
Fertilisers cannot simply be compared by weight due to their different application methods and nutrient concentrations. If you want to compare lawn fertiliser prices, you should always pay attention to the recommended amount of product per square metre and the recommended frequency of application.
There are generally very different recommendations: from 20 to 100 grams per square metre. This also depends on the chemical mixture. In general, you can simply follow the recommended dosage.
Time of application
Depending on when you want to fertilise your lawn, different fertilisers are suitable. Since special lawn fertilisers are produced for different application periods, which are characterised by different nutrient compositions, you should be clear about the season for which you need the fertiliser before buying it.
In spring and for the warm growing season, your lawn needs nutrients in different amounts than in the second half of the year, when you should use an autumn lawn fertiliser (a low-nitrogen fertiliser with a high potassium content). Many manufacturers also offer lawn fertilisers with nutrient combinations that are suitable for the whole year.
If your lawn shows yellow, curled or mottled leaves, purple shoots, poor growth and low flower and fruit production, you need to pay special attention to fertilising your lawn properly.
Toxicity / environmental friendliness
Lawn fertilisers are manufactured differently depending on the type of product and therefore require different amounts of energy and resources in their production. If you value sustainable production, an organic lawn fertiliser is the right choice for you.
In its production, leftovers from food production are reused. However, you should also know that slaughterhouse waste is sometimes recycled in the form of fertiliser. For mineral lawn fertilisers, nutrients are artificially produced or extracted from deposits.
Apart from production, it is also possible to assess how environmentally friendly a fertiliser is in your own garden. Organic lawn fertilisers represent the most natural variant. The natural carrier provides the nutrients that correspond to the natural nutrient supply of the lawn.
If you have decided to fertilise your lawn, but at the same time also want to remove the weeds in your turf, combination products that contain an additional weed killer are a good choice.
There are lawn fertilisers that contain a moss killer, for example. Depending on the type of weed you want to control, you should find out about the effectiveness of the fertiliser before buying it.
Duration of effect
Depending on whether you choose a short-term or long-term fertiliser, you should expect the lawn fertiliser to have a different duration of action.
While short-term fertilisers are not long-lasting but have a quick effect, you can expect many slow-release fertilisers to be effective for three to six months. The exact duration of action is always stated by the manufacturer on the fertiliser packaging.
Basically, lawn fertiliser can come in two forms: as granules and as liquid fertiliser. Here is an overview of the most important differences:
|Liquid fertiliser||Liquid fertiliser is particularly suitable for smaller lawns and can be applied very evenly and quickly. The fertiliser, which you buy as a concentrate, is mixed with water before use. Subsequent watering is not necessary. The effect of liquid fertiliser is not long-lasting.|
|Granular fertiliser||granular fertiliser comes in different sizes. It is usually cheaper than liquid fertiliser. The fertiliser can be spread evenly with a spreader. However, there is a risk that the granules will be blown away by the wind. Granular fertiliser usually has a long-term effect.|
Nitrogen is considered a growth engine because it offers the strongest yield response of all nutrients. It contributes above all to better green colouring. The usual proportion of nitrogen in fertiliser mixtures is between five and 22 percent.
The chemical symbol for nitrogen is N. Nitrogen is found in various forms in normal soil. On the one hand organically bound as humus, on the other hand in mineral form as nitrate or ammonium. Too little nitrogen in the lawn has three basic consequences:
- Chlorosis and necrosis of the older leaves
- Low tillering
- Poor root growth
Phosphorus is an energy carrier. It plays an important role in the cell function of the grass and mainly promotes root growth. The usual phosphorus content in fertiliser mixtures is between five and 15 percent.
The chemical symbol for phosphorus is P. Often, not pure phosphorus is used, but the P2O5 mixture phospohorentoxide. Phosphorus occurs in the soil as water-soluble, labile or stable forms of phosphate. A lack of phosphorus in the lawn leads to:
- Reddish leaf colour
- Reduced root growth
- Low tillering
- Poor growth and overall development
Potassium strengthens grasses against drought, cold and disease. It plays an important role in managing a plant's water supply and thus helps to increase the resilience of the lawn. Between five and 25 percent potassium in fertiliser mixtures is common.
The chemical symbol for potassium is K. Potassium is bound to clay minerals. Therefore, it occurs in different amounts in different soils. A lack of potassium causes the following in the lawn:
- Increased susceptibility to disease
- Leaf margin necrosis on older leaves
Weed killer additive
There are some fertilisers that have a weed-killing function in addition to providing nutrients. These are often also advertised as 2-in-1 products. The use of weed killers at the same time as other fertilisers or moss killers is strictly discouraged. It will kill your grass rather than improve it.
To fertilise and weed at the same time, it is best to buy a 2-in-1 or 3-in-1 fertiliser. Not every lawn needs a weed killer. However, if you have weeds such as stinging nettles, dandelions or white clover, it may be worth buying a slightly more expensive fertiliser with weed killer.
Facts worth knowing about lawn fertiliser
At what time should I fertilise my lawn?
The optimal time to fertilise is in the evening before a rainy day or night. The rain helps the nutrients of the fertiliser to reach the lawn. It is also recommended that the fertiliser is not left directly on the blades of grass, but directly on the soil. Otherwise, the chemical substances may burn into the lawn.
How do I apply the lawn fertiliser correctly?
Granulated lawn fertiliser should be distributed as evenly as possible over the lawn so that the grass grows evenly. To do this, the fertiliser can be spread by hand using gloves.
simple and convenient alternative is a spreader with which you drive over the lawn in lanes, similar to mowing the lawn. When filling the spreader, make sure that no fertiliser falls next to the container, as this can severely damage the lawn in the affected areas.
A tip on how to best apply the lawn fertiliser with the spreader: Halve the amount of fertiliser to be used and spread the first half in one direction on the lawn, the second half across. Here is a helpful video for you to learn how to spread the fertiliser evenly with a spreader and what you should pay attention to.
If the lawn has been freshly cut and is only a little high, the nutrients can be released more quickly because the fertiliser comes into contact with the soil more quickly. Be sure to water the lawn (for about 20 to 30 minutes) after fertilising.
A heavy rain shower has the same effect. Watering accelerates the effect of the lawn fertiliser because it dissolves more quickly and can thus seep into the soil in a liquefied form. If you use a liquid fertiliser, watering the lawn is not necessary, as you mix the concentrate with water before applying it.
How much lawn fertiliser should I use?
To find out which nutrients the lawn needs and to what extent, you can have a soil analysis carried out. In this context, the soil's content of phosphorus, magnesium and potassium will be examined.
The test also provides information about the soil type and pH value. In order to carry out such an analysis, samples are taken from 10 to 15 places in the lawn at a depth of about 10 cm, which results in a total of about 300 to 500 grams. This quantity is delivered to a testing laboratory.
The results can be used to determine the optimal fertiliser for your lawn. Often, the nitrogen content of the lawn is not also tested, which is why it is advisable to orientate yourself on the given guideline values.
For example, lawns that are used intensively and played on often need 18 to 25 g of nitrogen per square metre per year. Ornamental turf has a lower requirement. The recommendations of the soil test and the guideline value for nitrogen form the so-called pure nutrient quantity.
This is needed when calculating the amount of fertiliser required, which is necessary because lawn fertilisers do not consist of 100 percent of just one nutrient.
This is how you calculate the right amount of fertiliser for your lawn: Fertiliser quantity (g/m²) = pure nutrient quantity (g/m²) * 100 / nutrient content (%) in the fertiliser You will always find the nutrient content as a percentage value on the fertiliser packaging.
Remember that the amount of pure nutrients your lawn needs is based on a whole year. Therefore, you should divide the calculated fertiliser quantity into two or three loads, which you add to the lawn during fertilisation over the course of the year.
How do I dispose of lawn fertiliser correctly?
Since fertiliser residues must not be disposed of in waste water, it is best to dispose of them in their original packaging at a local garden centre or at a collection point for harmful substances.
If you have a compost area in your garden, you can also add small amounts of fertiliser residues to leaves, straw or wood chippings.
The micro-organisms will absorb the missing nutrients and enrich your compost, which small animals will enjoy.
How do I store lawn fertiliser correctly and what is the shelf life of lawn fertiliser?
When storing lawn fertiliser, make sure that it remains tightly sealed in its original packaging. A good place for dry fertiliser is, for example, a lockable cupboard in your garden shed, tool shed or garage - so that children or pets do not come into contact with the fertiliser and rodents do not eat the packaging.
Make sure that no moisture gets to the fertiliser. Also, avoid mixing different fertilisers so that you can apply the fertiliser correctly at a later date. Liquid fertiliser is best stored in a dark place without large temperature fluctuations.
Unless otherwise stated on the packaging, opened liquid fertiliser can usually be used for up to three years without concern.
If optimal storage conditions are observed, lawn fertiliser per se cannot go bad and remains effective.
If the fertiliser has changed visually and has clumped, for example, you can simply dissolve it in water and continue to use it. If some mould has formed on the fertiliser, you can remove the affected area and continue to use the rest.
What can I do if I have used too much lawn fertiliser?
You should act quickly if you have used too much fertiliser. You can take the following measures as soon as possible to prevent serious damage to your lawn:
- Remove as much granulate as possible from the affected lawn area with gloved hands.
- Rake the fertiliser granules out of the turf with a rake.
- Water the affected areas thoroughly and for a long time so that the increased nutrient concentration is diluted and reduced.
To prevent over-fertilisation, here are a few helpful tips for you:
- It is best to use organic lawn fertiliser. This is released only slowly, so the general risk of overfertilising the lawn is very low. In this case, over-fertilising is less serious than using a mineral fertiliser.
- If you do want to use a mineral lawn fertiliser, strictly follow the dosage and application instructions on the packaging.
- Always place fertiliser bags on plastic or stone surfaces and fill the spreader or bucket there.
- Check the function and setting of the fertiliser spreader before each use.
What is a burnt lawn?
Burnt lawn usually refers to partially dead brown grass or completely dead lawns. It is caused either by a lack of nutrients, incorrect fertilisation or poor watering.
Image source: Pixabay.com / Arcaion