When it comes to nutrient supply, lawns are very demanding. We will introduce you to different lawn fertilizers and make a comparison .
A beautiful lawn needs the right fertilizer [Photo: SingjaiStocker / Shutterstock.com]
The choice of lawn fertilizer not only determines the nutrient supply of the lawn, depending on the type of fertilizer chosen, the frequency and comfort of application, the risk of overfertilization or leaching, the effect on the lawn plants and the soil and, in the long term, even the subsequent need differ watering, scarifying or aeration. With the presentation of the most diverse types of lawn fertilizers, we want to give you an overview so that you can find exactly the lawn fertilizer that has the most advantages.
Special iron fertilizers, liquid fertilizers, nitrogen fertilizers, blue grain and lawn fertilizers with weed killers are all mineral lawn fertilizers. Liquid fertilizers and nitrogen fertilizers are also available in organic form and organic fertilization in particular offers many advantages, such as a natural long-term effect. Organic lawn fertilizers also have these advantages due to a high proportion of organic material, so that after a detailed comparison we ultimately consider them to be the best lawn fertilizers.
Organic lawn fertilizer
Table of Contents
The difference between organic and mineral lawn fertilizer lies in the “packaging” of the nutrients. While mineral fertilizers are available as pure salts of nutrients, organic fertilizers are bound in naturally grown structures. This has a number of advantages:
- These structures not only contain some main nutrients, but also various trace elements.
- It also contains a large number of carbon compounds, for example in the form of cell walls, carbohydrates and wood pulp (lignin). If there is a little more carbon or if the living conditions of the soil organisms are not optimal, some of the material remains unprocessed. From these half-decomposed materials, new humus molecules are formed in biological and chemical processes, which represent a kind of carbon and nutrient storage in the soil.
- Humus molecules also have special properties that greatly increase the quality of the soil.
- In addition to plant nutrients, the introduction of organic material also provides the basis of life for many extremely useful soil organisms and material for building new humus. This is particularly important because soil organisms, when there is a high level of nutrient input, make use of the carbon reserves of the soil without the provision of organic material: the existing humus.
Organic fertilizers must above all be used with foresight [Photo: SIM ONE / Shutterstock.com]
The conversion of organic material into the soluble nutrients that plants can absorb takes a certain amount of time. Finely ground organic lawn fertilizers release nutrients for the lawn faster than coarsely ground fertilizers. Warmth, humidity and a neutral to slightly higher pH value accelerate the work of the microorganisms. Nevertheless, organic lawn fertilizers must always be fertilized in advance: You should fertilize organically about a month before the nutrient requirement appears. You can also read more about organic lawn fertilizers in this article.
Organic lawn fertilizer
Both mineral and organic lawn fertilizers have their disadvantages: Mineral lawn fertilizers reduce the quality of the soil and organic lawn fertilizers have a delayed effect. Organic-mineral and organic-certified lawn fertilizers are the fusion of both types of fertilizer. The combination of organic and mineral components makes it particularly easy to effectively care for a lawn and the soil beneath it. Organic lawn fertilizers have the additional advantage that they only contain mineral components that can also be used in organic farming: the sources are demonstrably used as sustainably as possible. Organic lawn fertilizers are also available in animal-free form – including our Plantura organic lawn fertilizer and Plantura organic autumn lawn fertilizer. As a result, they are not only less odorous and suitable for strict vegetarians or vegans, but are also more resource-efficient due to the lack of “food processing” in the production chain. Incidentally, some organic fertilizers even contain living microorganisms such as useful mycorrhizal fungi or special bacteria that release nutrients. You can find out more about the fertilizing properties of organic lawn fertilizers in this article.
Long-term organic lawn fertilizer
Solid organic fertilizers always have a natural long-term effect. If humus is built up through use, the nutrients brought in can only be used by the soil years later if the soil is poorly fertilized. This long-term effect arises from the time it takes for microorganisms to release nutrients. This also means that the release depends on the living conditions of these organisms. In the following table we have summarized for you what leads to a faster or slower release and how these factors can be influenced.
|Faster release||Slower release||Influencing|
|warmth||cold||Pay attention to the shadows cast by trees and buildings when installing|
|Sufficient moisture||dryness||Introduction of water-storing clay minerals, increasing the humus content for water storage, frequency of mowing in summer (soil shading, cut stalks increase water loss), watering the lawn|
|Good floor ventilation||Bad soil ventilation due to waterlogging / soil compaction||Increase humus content through organic fertilization, scarifying, aerating and sanding, organic fertilization to stimulate soil life|
|High nutrient content of the fertilizer||Low nutritional content||Choosing the right fertilizer, if necessary incorporating additional, difficult-to-decompose material to slow down the release, or adding nitrogen to accelerate it|
|Soil pH in the neutral range||Acid pH||Occasionally check the soil pH value and lime if necessary|
Tip: A quick release always means that less humus is built up. If you also fertilize organically with the aim of improving the soil, you should therefore not over perfect the working conditions of the microorganisms.
You can find more information on the subject of long-term fertilizers for lawns here.
Mineral lawn fertilizer
Mineral lawn fertilizers contain the main nutrients nitrogen (N), phosphorus (P) and potassium (K) in mineral form. In addition, there are often other nutritional elements that act as partners in the formation of fertilizer salt. Often advertised with high magnesium and iron contents, which should ensure a healthy, green lawn color. Most of the nutrients contained come from fossil raw material stores, while nitrogen is synthesized from atmospheric nitrogen (N2) in the so-called Haber-Bosch process.
Mineral lawn fertilizers with a three to six month long-term effect are increasingly being offered, which are intended to make your work easier as a user and to limit leaching more or less well.
However, mineral lawn fertilizers do not contain any organic components and completely bypass the natural conversion processes of the soil. By using only mineral lawn fertilizers, the soil becomes depleted in useful soil organisms and even loses parts of its humus body. This ultimately leads to a reduction in the quality of the soil. As a consequence, there can even be additional effort in maintenance: scarifying and aeration are required more frequently, wild herbs can be promoted and fertilization errors are more serious.
The use of mineral lawn fertilizers can lead to a deterioration in the quality of the soil [Photo: Singkham / Shutterstock.com]
Unfortunately, cheap mineral lawn fertilizers are often more heavily contaminated with cadmium, chromium or even uranium. These heavy metals can accumulate in the soil, in groundwater, in plants and finally through composting in the entire human food chain. Of course, there are limit values for exposure to toxic heavy metals in Germany and the EU, and these have also been revised downwards several times in recent years.
Tip: Together with the reduction in soil quality, the consumption and the scarce recycling of phosphorus represent a major environmental problem: The deposits for unpolluted rock phosphates will be used up in a few decades, and deposits with heavy metal-contaminated rock phosphates are already being used. Many experts are therefore of the opinion that the era of mineral fertilization in agriculture must come to an end in order to conserve resources such as soil and nutrients and not to introduce further heavy metals.
Summary: Mineral lawn fertilizers
- In addition to nitrogen, phosphorus and potassium, it also often contains magnesium and iron
- Organic components and other trace nutrients are missing
- Long-term mineral lawn fertilizers extend the fertilization interval and protect – depending on the type of processing – more or less against loss through leaching
- Sole use leads to a reduction in soil quality and impoverishment of soil life, which results in additional horticultural effort
- In particular, cheap mineral lawn fertilizers are more heavily contaminated with harmful heavy metals
Iron fertilizer for the lawn
Iron is one of the 14 essential nutritional elements and is not only required by the lawn for the synthesis of various enzymes and chlorophyll. For this reason, it is often used in lawn fertilizers to create a very green lawn. Unfortunately, soil and nutrient chemistry is a little more complicated than some fertilizer manufacturers suggest: Iron is one of the most common elements in our soils. An absolute deficiency – i.e. the complete absence of iron – is extremely unlikely. It is much more likely that there is a relative deficiency that cannot be permanently remedied by iron fertilization, although plants only need very small amounts of iron. Optimizing the growth conditions for the lawn is the cheaper and more natural way of preventing iron deficiency, because lawn grasses are able to absorb iron very efficiently. You have an intake strategy that is unique in the plant world. So before you start spending your money on something that is perfectly adequate in your own soil, it is best to read this detailed article on how to supply your lawn with iron.
Iron fertilizer can only prevent moss from appearing in the lawn for a short time [Photo: philmillster / Shutterstock.com]
Tip: The use of iron sulphate against moss in the lawn is recommended far too often. You can also read about why this only leads to the moss dying off in the short term and even increases the amount of moss in the long term in the aforementioned special article on iron fertilization of the lawn. Here you will also find tips for really effective control of moss in the lawn.
Blue grain for the lawn
Blue grain is a well-known universal mineral fertilizer. It has been copied many times by different manufacturers, but usually only externally, the nutrient composition and quality, however, can differ. “Blaukorn Classic” contains 12% nitrogen, 8% phosphorus oxide, 16% potassium oxide, 3% magnesium oxide and 10% sulfur. Other products in the “Blaukorn” range may have a different composition or contain special inhibitors that prevent nitrogen leaching.
Blue grain is less suitable for lawn fertilization [Photo: sarka / Shutterstock.com]
Blaukorn has all of the above-mentioned disadvantages of a mineral lawn fertilizer and, thanks to its universal composition, is by no means tailored to the specific needs of the lawn. An application for autumn lawn fertilization would result in environmental pollution as a result of the leaching and incorrect fertilization. The latter would cause frost damage to the lawn and thus also hinder the good start of the lawn plants in the coming year. If you want to find out more about fertilizing your lawn with blue grain, you will find it here.
Because of the frequent cutting, the lawn has an increased need for nitrogen. As the “motor of vegetative growth” it is essential for the synthesis of DNA, enzymes and chlorophyll. An inadequate supply of nitrogen not only leads to a rare mowing, but above all to gaps, weakly competitive lawn, which cannot suppress wild herbs and moss well. An acute nitrogen deficiency is shown by a complete yellow coloration of the oldest lawn grasses. Nitrogen fertilization alone is usually not necessary, the optimal solution is a lawn fertilizer that covers all the nutrient withdrawals from the lawn.
If there is a nitrogen deficiency in the lawn, this can be seen, for example, in the colouration of the grass [Photo: SingjaiStock / Shutterstock.com]
Especially in spring and over the summer, the lawn has a high nitrogen requirement. However, if the year is heading towards autumn, you should gradually reduce the nitrogen fertilization, because stalks with a strong nitrogen supply are soft and can hardly do anything to counter frosty temperatures. For this reason, the effect of nitrogen-stressed long-term lawn fertilizers should expire at the latest in August and fertilization that emphasizes potassium should begin. We recommend the organic supply of the lawn with nitrogen in order to prevent losses through leaching and over-fertilization. If you have to treat an acute deficiency, an organic-mineral fertilizer or an organic liquid fertilizer is also suitable. Detailed information about nitrogen fertilization of the lawn can be found here in our special article.
Liquid lawn fertilizer
Plants can absorb nutrients not only through their roots, but also in small quantities through all organs above ground. Liquid lawn fertilizers take advantage of this fact. Both mineral and organic liquid lawn fertilizers are available. These advertise with an extremely fast effect and an immediately green lawn. The uptake rate is extremely different depending on the nutrient, but nitrogen quickly gets into the lawn plants via the leaves. The even distribution and simultaneous watering of the lawn, which is also completely dust-free, should also offer an advantage. Even liquid lawn fertilizers with “long-term effects” are offered. However, the disadvantages of liquid lawn fertilizers should be clearly visible to every lawn owner:
- Application leads to sudden growth; As a result, the lawn is often not well prepared for diseases, heat or cold
- If the dosage is incorrect, high nutrient concentrations quickly lead to over-fertilization
- The often contained nitrogen form urea is difficult for laypeople to assess; It easily leads to a loss of nitrogen to the environment and thus to a loss of utility for the paying customer
- The usually small pack size is due to the better applicability, but it increases the price per fertilized square meter
- Mineral liquid lawn fertilizers bring in organic matter and therefore deteriorate the soil quality with repeated use
These are just a few of the disadvantages that are relevant to you and that the use of liquid lawn fertilizers entails and which should lead you to refrain from using them.
Liquid fertilizers are also partially absorbed through the above-ground organs of the grasses [Photo: Piyaset / Shutterstock.com]
Organic lawn fertilizers in liquid form are – if such an application is urgently required – still the best form of liquid fertilization, because in addition to mineral nutrients they contain some organic matter and many trace elements, and the production is more sustainable. But remember: With regular lawn fertilization, you will not end up in a situation in which extremely fast lawn fertilization is even necessary. You can find more detailed information in our special article on this topic. This article also tells you about liquid fertilizers in general – and how you can even make them yourself.
Lawn fertilizer with weed killer
Wild herbs in the lawn do not bother every lawn owner, but some are waging a real war against dandelions ( Taraxacum sect. Ruderale ), daisies ( Bellis perennis ), white clover ( Trifolium repens ) or mosses ( Bryophyta ). In addition, some lawns seem to be more affected by the pejorative wild plants called “weeds”. Anyone who no longer knows what to do with mechanical means such as cutting out, mowing or tearing out may come up with the idea of using a lawn fertilizer with a weed killer. This should combine the supply of the lawn grasses with fast-acting mineral nutrients and the control of wild herbs.
Wild herbs such as daisies are supposed to be destroyed by lawn fertilizers with weed killers [Photo: Flower_Garden / Shutterstock.com]
As beautiful as this promise is, the use of lawn fertilizer with weed killers should not be done lightly – it has the following disadvantages, among others:
- The herbicidal substances can be harmful to wildlife, domestic animals and the user
- Weed grasses remain unaffected by the use of herbicides, since the agents contained must of course be harmless to grasses
- If handled carelessly, various other garden plants can also be damaged
- The sole use of mineral lawn fertilizers leads to a loss of soil quality and can disrupt soil chemistry to such an extent that the pH value changes. This in turn can favor the growth of wild herbs
You can find more information about lawn fertilizer with weed killer and more effective prevention and control of weeds in this special article.
The best lawn fertilizer
The direct comparison of organic and mineral lawn fertilizers reveals the weaknesses and strengths of the two types of fertilizer. While organic lawn fertilizers have a slow effective speed, mineral lawn fertilizers have a negative impact on soil properties and thus on lawn health. For this reason, our conclusion after a closer look at the two types is that the combination of mineral and organic elements in lawn fertilization unfolds the most positive effect.
Our Plantura organic lawn fertilizers with long-term effects are ideally tailored to the needs of the lawn
Mainly organic lawn fertilizers in organic quality with long-term effects are for example our Plantura organic lawn fertilizer and our Plantura organic autumn lawn fertilizer. We have summarized further information on organic and mineral lawn fertilizers and the optimal care of your lawn for you in this article.
You can find out everything about “fertilizing the lawn” – from the right time to the right approach to fertilizing – in our overview article.