Opinions are very divided on the subject of liming the lawn. Liming should help against moss in the lawn, at least the providers promise and swear so. Others say on the other hand that lime in the lawn is of no use, and can even damage it. I am not an expert now and will summarize here what I found out during my research. In the end, the only thing that helps is to try it out again and find out for yourself. What I know for sure is that it always depends on the circumstances, i.e. location (a lot of shade), plant substrate (very solid soil) and water supply (very moist soil). In poor conditions you can lime, fertilize, cherish and care for and the lawn will still never look really great. So I can’t give you an all-inclusive tip. It only helps to test.
You should therefore always be the first to commission a soil analysis. Until you have this result, there is no point in doing anything. This is how the pH value can be determined. As a rule, parts of the lawn that are slightly shaded are more acidic than those that are constantly in the sun.
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Why is lawn being whitewashed?
If there is moss on the lawn, it is usually because the soil is too acidic. Moss loves this acidic soil, grows and thrives and displaces the lawn. If the soil analysis has confirmed that a light soil needs lime, it should be limed. It is best to do this in March, as soon as you are reasonably certain that there is no more snow. The ideal pH value for lawns is between 5.5 and 6.5.
Lime has a major impact on soil fertility. It stimulates the soil life, also improves the crumb structure, promotes rooting, promotes the metabolism in the soil and ensures firm cell walls in the plants. Too little lime affects the absorption of crucial nutrients, too much lime on the other hand that of iron and trace elements. The soil structure is only improved with an optimal lime content and nutrients and trace elements can be absorbed by the lawn.
The lawn season begins with liming and the aim is to neutralize the soil so that the grass regains the upper hand. Scarifying and liming alone is usually of no use if the soil is not improved at the same time.
- Many gardening professionals recommend liming in autumn for the reason that the soil is fertilized in spring. However, lime should not be applied with nitrogenous fertilizers, because lime drives out the nitrogen. So autumn fertilization really makes more sense.
- Carbonate of lime reacts very slowly. This is another reason why autumn fertilization makes more sense, as it gives you enough time.
- Lime consumes huge amounts of humus. So when liming is used, sufficient humus must be provided afterwards.
- If the pH value is in the ideal range during the measurement and there is still a lot of moss growing, liming must not be carried out. That would weaken the supply of nutrients to the grass. The result would be even more moss. Then the appropriate fertilization makes sense after the moss has been removed, of course.
Warning: If there is a lot of clover on the lawn, the soil is very basic. Then liming is not recommended, because it becomes even more basic. This can lead to the grass being deprived of its livelihood and being seriously damaged.
Which lawn lime is recommended?
Many hobby gardeners only know fertilizer lime, quicklime and vital lime, but there is a lot more. Different means are used depending on the soil.
The amount of lime that should be used depends on the pH of the soil, but also on the amount of humus and the nutrient content present.
There are different offers for lime. Many recommend very fine lime, others swear by granular products because they are easier to distribute, simply more evenly.
- Fertilizer lime – rather a summary of some types of lime (collective name)
- Quicklime – works very quickly, but is only suitable for very heavy soils and generally not recommended, as it has an unfavorable influence on soil biological influences.
- Vital lime – carbonate lime, contains peat, magnesium, trace elements and Azotobacter bacteria. Well suited for lawn fertilization, but about 10 kilograms per 100 square meters are required. Good for organic gardens.
- Quick lime – is unslaked lime, must not simply be used! Must be deleted first!
- Limestone flour – also carbonate of lime, which is sparingly soluble in water and is therefore mostly used in autumn and winter.
- Rock flour – contains potash, lime and magnesium and various trace elements. It works slowly because, similar to bone meal as a fertilizer, the active ingredients first have to be broken down by microorganisms.
- Slaked lime – has a similar effect to quicklime and is not recommended.
- Dolomite – carbonate of lime, contains a lot of magnesium and is therefore used when there is a simultaneous magnesium deficiency. Inexpensive on light soils.
- Thomas flour – is suitable for acidic soils. It is a waste product from ore smelting and contains plenty of phosphorus as well as manganese and trace elements.
- Algae lime – my favorite – is extracted from coral deposits. Rock flour with a high proportion of lime, 80% carbonate of lime, plus plenty of magnesium, silicates and trace elements. Can be applied all year round. Good for biological balance. The risk of over-fertilization is low, in contrast to other means.
As already mentioned above, the dosage depends on various factors. If you have no special location, soil or irrigation problems, you can dose as follows:
To convert the pH from 5 to 6, use per square meter
- 200 grams of pure lime
- 400 grams of carbonate of lime
Depending on the type of soil in the year
- On light soils – 6 to 8 kg for 100 m²
- For medium floors – 8 to 13 kg for 100 m²
- For heavy floors 12 to 18 kg for 100 m²
- 60 to 80 g per m²
10 kg of lime on 100 m² seems like a lot to me. I would spread that over several years. Otherwise this is really a radical intervention in the life of the soil.
It is often better to scatter small amounts, even if you then have to do this more often. Once the pH has been corrected and returned to normal, it usually takes two or three years before something has to be done again. It is best to check the pH once or twice a year.
Sandy soils usually need lime fertilization more often than heavy clay soils, for example. These can bind lime better.
Alternative to liming
Garden enthusiasts, who rate limescale as not that good, usually recommend spreading compost as an alternative. Rock flour can be mixed in. Spreading compost is not only beneficial for the lawn, it can and should be used throughout your garden. The pH is increased. At the same time, humus is added to the soil. In any case, this is good for the garden and the lawn, so there is no need for discussion.
Preparatory work for liming
It is advisable to scarify before liming. A lot of moss is removed from the lawn. Other foreign growth is also pulled out of the ground. It is also really well ventilated. You scarify in the spring before the grass starts to grow again. Depending on the lawn area, a lot of waste is created when scarifying.
How is liming done correctly?
The first thing to do is to take some precautions.
- Wear gloves! Never let lime come into contact with bare skin. It can cause chemical burns.
- It is best to wear old clothes, in any case with long sleeves.
- Use old shoes too. You get terribly dirty, especially if you scatter with your hand.
- A spreader is recommended for larger areas because it is spread more evenly.
Step by step
- Mow the lawn (cutting height 4 cm)
- Scarify the lawn (rake or scarifier)
- Spreading lawn lime (by hand or with a spreader)
- Water the lawn (rain or water hose)
After liming – resting phase
After liming, watering is very important. That is why it is best to whitewash before it rains. This allows the lime to penetrate the soil more quickly. He’ll be okay sooner. Burns can occur if you do not get wet after lime. Then you should let the lawn rest. Under no circumstances should fertilization be carried out shortly after liming!
Lime dangerous for dogs and cats?
Lime is not as dangerous as some mineral fertilizers, but also not entirely without it. Dogs and cats are very clean animals and they clean their feet. When they lick, they take in the lime that sticks to and between their toes. That’s why I would definitely recommend organic lime, which would mean algae lime again, but I also have a dog.
With the other types of lime, it certainly makes sense to ban gardening for two or three days. If it rains properly or the lawn is watered, there should be no more lime on the surface. The animals would no longer be in danger.
So there is no agreement about the liming of lawns. It helps against moss, but only if the acidic soil is to blame for the moss growth. Otherwise scarifying is the better solution. But if the soil is too acidic, liming makes sense. The ideal is the use of an organic lime. My favorite is algae lime. This can also be used in the entire garden. There is no over-fertilization and children and pets are not disadvantaged if the lawn is freshly limed.
In any case, a soil survey is useful. The pH value must be determined in any case. It’s also very easy. The test set is available in every DIY store and garden center. Then only trying it out will help. You can tell whether liming is beneficial by treating only half of the lawn with it. This is the best way to see the difference.