The Lawn Doctor – First aid for lawn problems

Your lawn should be green, lush, dense, and healthy. However, even well-maintained lawns can sometimes develop yellow patches, moss, weeds, burns, and other damage. To get your lawn back to its beautiful green state, you need to know what is currently stressing it. We'll show you how to identify and fix lawn problems.

One of the most common problems for lawn owners is moss, which can spread between the grass and even take over large parts of the lawn area. It also often spreads between paving stones – read on to learn how to get rid of it there.
 

Possible cause:

Incorrect seed mixture for the location

What the Lawn Doctor says:

To prevent moss from taking hold in your lawn in the first place, you can set the stage right from the start. The key is to choose the appropriate grass species when establishing the lawn area. If the lawn is located in a shady area of the garden, select a seed mixture that contains 5–10 percent creeping red fescue. You can find the species composition of the grass seed mixture on the packaging. Only shade-tolerant species can establish themselves in such locations. Other grasses may remain sparse and eventually disappear over time. This way, moss has a clear path to quickly take over the area.

Possible cause:

Compacted soil or waterlogging

What the Lawn Doctor says:

For a new lawn, deep soil loosening creates the best starting conditions. Lawns will struggle on compacted soils. If the soil is heavily compacted, aerating the soil can help. This involves creating approximately 10 cm deep holes in the soil using an aerator, allowing water and air to penetrate the soil zone. Ideal for aerating are hollow tines that extract soil material. Alternatively, you can use a simple garden fork, pushing it several times into the lawn area and moving it back and forth lightly. Lifting the soil slightly will also loosen it. Fill the resulting holes with sand to keep them permeable to water, air, and nutrients for a long time.

Possible cause:

Sparse lawn due to improper care

What the Lawn Doctor says:

If moss appears on your properly established lawn, it can have various causes. Moss can establish itself due to improper mowing practices. Regular mowing is important, but a utility lawn should not be mowed shorter than 4–5 cm. If the lawnmower is set too low, it can significantly damage many grass species, leading them to recede subsequently. Once moss has spread, special measures must be taken to combat it. For loose patches of moss, you can use a scarifier, which pulls the moss out of the lawn. The Universal Verticut 1100 also cuts into the soil, promoting new grass growth. You can rent scarifiers at garden centres and hardware stores. After scarifying, level the lawn and provide it with slow-release fertiliser to encourage grass growth and make the lawn dense again. To prevent soil compaction, you can rake a small amount of sand (1 litre per square metre) into the previously scarified turf. If there are larger gaps after removing the moss, you should overseed.

Possible cause:

Acidic soil

What the Lawn Doctor says:

The pH level of the soil is crucial for your lawn. If it's too low, the soil is acidic, causing the grass to recede and allowing moss to take over. To determine the pH level, you can use a soil pH test. If the pH level is indeed too low, the soil benefits most from lime. The best time to apply lime is early spring, around February to March. We recommend spreading 150 g per square metre of ground limestone. Since lime is fine as dust, it's best to apply it on a calm day, preferably with a spreader. If the pH level is too high, you can fertilise according to the instructions with Epsom salt, iron sulphate, or ammonium-containing nitrogen fertilisers.

Possible cause:

Nutrient deficiency

What the Lawn Doctor says:

Another cause for the spread of moss could be insufficient nutrient supply. If there is a lot of moss in the lawn, using speciality products such as moss-killer fertiliser is recommended. It's best to apply such a product in the spring. If moss reappears during the year, you can repeat the treatment in early autumn.

Possible cause:

Lack of light or autumn leaves on lawn areas

What the Lawn Doctor says:

Are there still leaves on your lawn that haven't been cleared before winter? It robs the grass blades of light and they wither. You can conveniently collect it, for example, with the Bosch Universal LeafBlower, and the Universal GardenTidy 2300 leaf blower can even vacuum up the leaves. A shady spot can also become a problem. Under conifers and walnut trees, it can also be difficult for the lawn – but here it is less about the light, but rather the dense carpet of needles on the ground and the root competition or juglone, which the leaves of the walnut tree secrete and thereby prevent growth all around them.

Just like with moss in the lawn, there are various causes for the appearance of weeds and grasses. Among the troublesome plants are especially clover, but also dandelions, plantains, daisies, and especially annual meadow grass among the grasses. It's entirely up to you when the herbs and grasses become too much for you and you want to take countermeasures. In ornamental lawns, weeds are usually not tolerated, although daisies and clover are not so bad on a play lawn.

Possible cause:

Wrong seed variety

What the Lawn Doctor says:

To prevent weeds from appearing in the first place, the right grass seed mixture is crucial once again. Firstly, the grasses must be suitable for the location, and secondly, inferior seed can also contain weeds and unwanted grasses. Therefore, when establishing new lawns, use RSM-certified seed, as these mixtures guarantee purity.

Possible cause:

Nutrient deficiency

What the Lawn Doctor says:

To banish clover from the lawn, it helps to ensure that the area is adequately supplied with nutrients.

Possible cause:

Persistent weeds

What the Lawn Doctor says:

Some wild herbs can be mechanically removed with a scarifier. If there are only a few troublesome herbs, you can easily dig them out with an old knife. However, there are now also semi-automatic weed pullers available that can make the job easier for you.

If none of these measures help, you may consider using selectively acting herbicides. However, only products labelled “approved for use in household and small gardens” should be used. Before using any herbicides, make sure to inquire with agricultural offices, gardening academies, or speciality stores.

Various fungal pathogens can affect your lawn. Fungi spread when:

• The grass becomes too tall over winter
• The turf is too dense
• Leaves are left on the lawn and not cleared away
• The lawn is in shade and the wrong types of grass seed were sown
• Too much nitrogen was applied in autumn
• A layer of snow remains for weeks
• There is a potassium and micronutrient deficiency in the grasses

Possible cause:

Snow mould

What the Lawn Doctor says:

Snow mould occurs between September and March. You can recognise the disease by small round patches that grow larger in spring, merge together, and are covered with a white-grey to reddish coating. You can combat the fungus by verticutting and aerifying. As a preventive measure, you should mow the lawn regularly, remove leaves in autumn, and apply a potassium-rich fertiliser.

Possible cause:

Red thread disease

What the Lawn Doctor says:

Red thread disease mostly occurs between June and October. You can recognise it by irregularly shaped patches and grass blades with pinkish tips. Additionally, the lawn may appear dried out. Mow regularly and remove the clippings. A robotic lawnmower can assist with this task by not only cutting the grass but also collecting the clippings. You can learn more about its advantages and disadvantages here. Proper fertilisation according to the lawn's needs can help prevent this disease.

Possible cause:

Rust disease or lawn rust

What the Lawn Doctor says:

From April to September, yellow to brown pustules may appear on the grass blades. These symptoms indicate rust disease, with the grass often looking weak. Host plants for the rust fungus include barberry and mahonia. If these shrubs are near the lawn and the disease becomes severe, they should be removed. To prevent it, you should mow regularly but not too deeply and fertilise according to the lawn's needs.

Possible cause:

Leaf spots

What the Lawn Doctor says:

Oval, dark brown, with whitish centres, leaf spots occur from April to September. Reduce nitrogen fertilisation to contain the fungus. Also, verticutting and not mowing too deeply can prevent or combat leaf spots.

Possible cause:

Fairy rings

What the Lawn Doctor says:

The symptoms are familiar to many lawn owners. Fairy rings are caused by various types of fungi and can occur throughout the year:
Type 1: The grass dies in a ring shape, with a dark border zone forming on both sides of the fairy ring.
Type 2: A dark green ring with increased growth forms, and fruit bodies may appear temporarily.
Type 3: Circularly arranged fungal fruit bodies are visible on the lawn.

The fungi responsible for fairy rings do not directly damage the lawn, but they feed on organic matter. If the grass becomes dry, it may be due to water deficiency in the root zone or toxic breakdown products caused by the fungi. Because fairy rings can be quite stubborn, it's better to prevent them by avoiding soil compaction through verticutting and aerating. Fertilise with slow-release fertiliser to prevent both over- and under-fertilisation. If you already have a fairy ring, puncture the mycelial layer of the fungi, for example, with a digging fork. Then, you should water thoroughly, preferably enriching the water with a wetting agent to improve water retention capacity.
 

Especially voles and ants, but also moles, can appear more frequently in the lawn and cause damage. They should be gently discouraged, as they are sometimes considered beneficial animals in the garden.

Possible cause:

Moles

What the Lawn Doctor says:

Moles loosen the soil and consume harmful larvae. So, initially, you should be pleased when moles visit you. However, if they become more prevalent in the lawn, they can indeed become bothersome and even destroy the turf. There are various methods for repelling them, such as pouring sour milk or vinegar into their burrows.

Possible cause:

Voles

What the Lawn Doctor says:

Voles not only enjoy vegetable and flower roots but also grass roots. You can spot their activity when slightly elevated burrows are visible in the lawn. To restore soil contact to the grass, you should level the burrows. Using traps for control is permitted.

Possible cause:

Ants

What the Lawn Doctor says:

If ants are appearing more frequently in the lawn, you can water the nests at short intervals. This displeases the ants, and they will migrate away.

If you have ruled out the previous causes and your lawn still has gaps, then heavy usage, waterlogging, fertilisation errors, or heat could be possible reasons.

Possible cause:

Heavy usage

What the Lawn Doctor says:

Intense use of the lawn, such as frequent soccer games or inadequate fertilisation, can lead to gaps in the grass. If the lawn area is shaded by large trees, the tree roots absorb water and nutrients, causing the grass to weaken and recede. To avoid such bare patches, the lawn should not be subjected to excessive stress. Give it more rest periods and use a robust grass seed mixture for overseeding. If the grass under trees continues to thin out, you should water and fertilise those areas more frequently. Are you aware that you and your family will be using the lawn intensively? Then plan a family-friendly garden.

Possible cause:

Waterlogging

What the Lawn Doctor says:

If waterlogged spots appear in the lawn, it may be due to a soil rich in clay. Compacted soil can hardly absorb water, so when it rains heavily, the water simply pools on the surface. The best solution is to excavate the soil at the affected spots, mix good garden soil with gravelly sand in a 1:1 ratio, and fill the excavated area. Then, sow new grass seeds and press them down, for example, with the back of a rake. Water thoroughly until the grass begins to grow.

Possible cause:

Fertilisation errors

What the Lawn Doctor says:
Too much fertiliser can be just as harmful as too little. If your lawn turns yellow in some spots, it could be due to over-fertilisation. Incorrect pest control measures can also cause yellowing or discolouration. Reduce the amount of fertiliser and follow the instructions on the packaging. If pest control measures are necessary, seek advice from a specialist store beforehand. It's essential to adhere to the recommended dosages.

Possible Cause:

Heat or drought

What the Lawn Doctor says:

During prolonged extreme heat, grass can literally burn, and very dry winters also take a toll on the lawn. Extended periods of dryness lead to drought damage in the lawn. In such cases, you should rake away dead grass and dispose of it in your compost, then loosen the soil layer below with a digging fork. If bare patches have formed, a lawn repair mixture can help. Ensure adequate watering until the grass begins to regrow.

If you want to know more about when various gardening tasks need to be done, you can consult our garden calendar, which provides the right timing for all essential activities.