Nitrogen fertilizer ensures a lush green lawn. Here we explain how to optimally supply your lawn with nitrogen and what needs to be considered.
All plants need large amounts of nitrogen, and lawns in particular have a particularly high need for it. In this article you can learn how and when to best apply nitrogen and how to identify a nitrogen deficiency or excess. You will also receive tips on choosing the right fertilizer.
A lawn can only show the desired properties if it is supplied with nutrients according to its needs. The lawn is a heavy consumer, so it needs all nutrients in relatively large quantities. Nitrogen (N) is of enormous importance for all plants - including the lawn. It is a component of chlorophyll, DNA and many proteins necessary for plant life and development.
Why does the lawn need nitrogen?
As the “motor of vegetative growth”, it is required by lawns in particularly large quantities because nitrogen is constantly being removed from them in the form of lawn clippings as a result of the recurring mowing. Anyone who concludes that omitting nitrogen fertilization leads to a beautiful lawn with less mowing work is unfortunately on the wrong track. Frequent mowing alone stimulates the constant branching of the lawn plants. This results in a dense and hardwearing turf while effectively suppressing weeds.
Nitrogen fertilizer: when to fertilize?
Nitrogen as the "motor of vegetative growth" fuels the lawn instinct. This is very welcome in spring and summer when a lawn is mowed and used a lot. A strong shoot also means a strong competitive power against wild herbs. But there are times when little or no nitrogen is needed and even causes damage. At the beginning of spring, when the weather is mild, the lawn is roused from hibernation with a fast-acting, nitrogen-rich lawn fertiliser. ProblematicThis will happen when heavy frost sets in again after a few mild days. The driven stalks still have a low frost tolerance and can therefore easily freeze to death. They die off, lie yellow on the rest of the lawn, shade it and thus prevent further growth. You can find out here in our special article whether your lawn needs lawn fertilization in the spring to sprout.
In early autumn you should prepare the lawn for the cold temperatures of winter. If nitrogen-rich fertilization is carried out too late in the year and the nutrients are suddenly available, the same happens as described above for spring. The sprouting stalks are not sufficiently frost hardy and the lawn is more likely to go into winter damaged. We therefore recommend that the last lawn fertilization should not be carried out too late. In this article you can find out about the correct lawn fertilization in autumn.
Tip: Use a primarily organic lawn fertilizer such as our Plantura organic lawn fertilizer. You can apply this from the month of February and its release depends on the weather. The nutrients only become available to the plants slowly, so that there is no sudden surge of frost-sensitive stalks. Therefore, organic lawn fertilizers can still be used in autumn without hesitation.
Even in very hot summers, nitrogen fertilization can be problematic. Lawn growth stimulated by a lot of nitrogen is also not well positioned to deal with dry air and lack of water. The result can now be drought damage, after all the stalks can no longer compensate for their high transpiration rate with water absorption. Since mowing too often in hot summers also damages the lawn, you should avoid mineral fertilizers with too high a nitrogen content during these months.
Nitrogen fertilizer against moss in the lawn
A sufficient supply of nitrogen is always the indispensable basis for preventing moss growth. Because what is certain is that an insufficiently nourished lawn is not competitive enough to keep moss in check. But moss in the lawn can have other causes: lack of light, lack of oxygen at the roots due to waterlogging and/or soil compaction are just as possible as a soil pH value that is too low (below 6). Since these various causes - also in combination - cause moss in the lawn, strong nitrogen fertilization is by no means a panacea against moss in the lawn. If you want to learn how to combat moss in the lawn, you can also take a look atthrow this special item.
Detect nitrogen deficiency in lawns
Because lawns require a large amount of nitrogen, a deficiency quickly becomes noticeable. During the growing season and mowing season, you can recognize it by the slowdown in growth and associated fewer mowings. Now at the latest it is time to supply nitrogen in the form of fertilization. An acute deficiency can be recognized by the complete yellowing of the grass, because nitrogen is needed to build up chlorophyll. However, freshly sprouted stalks are often still green because nitrogen can be transported from the old leaves to the new ones. If your lawn is chronically under-nourished, this can be recognized by a thin turf through which the soil shimmers everywhere. Many weeds in the lawn also indicate malnutrition: Some of them can cope with fewer nutrients than the lawn plants. However, over-fertilization of lawns with nitrogen is also possible: This special article deals with over-fertilization of lawns.
Tip from the professional: Clover and dandelion are indicators of nitrogen deficiency or excess. White clover (Trifolium repens) is adapted to lean, nitrogen-poor soils. As a legume, it is able to enter into a symbiosis with so-called rhizobacteria, which bind nitrogen from the air and make it available to plants. For this reason, the presence of clover in the lawn indicates a lack of nitrogen nutrition. Unfortunately, this does not mean that the clover disappears after a fertilization: once it is well established, sometimes only generous removal and reseeding helps to get rid of it. Dandelion (Taraxacum sct. Ruderale) prefers the exact opposite: it prefers to grow in nutrient-rich locations, indicating that there is no deficiency.
You can find out here how to banish white clover, dandelions and other weeds from your lawn.
Nitrogen Lawn Fertilizer: Application and Application
Even if nitrogen is of outstanding importance for the lawn, nitrogen fertilization alone is not necessary. The necessary nitrogen is usually applied in combination with the other plant nutrients as lawn fertilizer. The nitrogen requirement depends on how the lawn is used: a hard-wearing lawn that is used heavily and mowed frequently needs 20 to 30Grams of pure nitrogen per square meter per year. On the other hand, 10 to 20 grams of pure nitrogen per square meter and year are sufficient for a typical lawn. The percentage nitrogen content can be found on the declaration of the fertilizer used.
The specification "10 - 4 - 6 - 2" indicates that it contains 10% nitrogen, 4% phosphorus compounds, 6% potassium compounds and 2% magnesium compounds. Therefore, if you apply 1 kg of such fertilizer, you have distributed 100 grams of pure nitrogen.
When dosing nitrogen and lawn fertilizers, you should always follow the recommendations of the respective manufacturer. Note that the amount of pure nitrogen applied at once should never exceed the limit of 5 grams per square meter for mineral fertilizers. Otherwise the lawn could be washed out and damaged. To stay within this limit anywhere on the lawn, we recommend using fertilizer spreaders where the size of the lawn allows. Applying larger quantities as long-term fertilizers or organic fertilizers is unproblematic.
Organic Nitrogen Fertilizer
Some organic fertilizers mainly contain nitrogen and can be used to nourish the lawn. However, always remember that the other nutrients are also necessary for maintaining a he althy lawn. Horn fertilizers contain 10 to 14% nitrogen. Depending on the degree of comminution, they act at different speeds: horn meal faster than horn semolina and the latter faster than horn shavings. During the growing season, you can apply 50 grams of horn meal per square meter every six weeks. The use of coarser horn fertilizer allows larger doses and longer fertilization intervals. Unless the soil under your lawn has a proven excess of potassium, phosphate and magnesium, it is better to fertilize with a full-fledged lawn fertilizer. For the sustainable fertilization of your green areas, we have developed our primarily organic Plantura organic lawn fertilizer and our organic Plantura organic autumn lawn fertilizer, which ensure that the lawn is treated gently while at the same time improving the soil quality.
Mineral Nitrogen Fertilizer
Pure mineral nitrogen fertilizers are not actually needed or used in the private sector. The reason lies in the numerous dangers that the use entails: over-fertilization, leaching and frost damage are associated with mineralsFertilizers and especially with nitrogen much more often than with organic or organo-mineral fertilizers. In the event of an acute nitrogen deficiency, the application can certainly be useful: liquid lawn fertilizer with urea or the application of calcium ammonium nitrate works many times faster than any organic nitrogen fertilizer. However, since an acute deficiency can be avoided with the regular use of long-acting lawn fertilizers, their use should be the exception and not the rule.
You can find more information about the different lawn fertilizers here. You can also find out more about "fertilizing your lawn" here in our overview article.