Whether you are new to the world of lawn care or a seasoned gardener, you will have likely heard the term ‘thatch’.
Thatch is a natural occurrence in most lawns, but if it is not managed effectively, it can cause problems for your grass.
In this guide, we explore what thatch is, what causes it, how to remove it, and how to prevent it.
What is thatch?
Thatch is a build-up of organic matter and debris, like dead leaves and clippings, that forms a layer between the grass blades and soil.
You can usually tell if your lawn has thatch just by walking on it, as it will feel soft and spongy.
| Fast Facts Less is definitely more when it comes to thatch, as below ½ an inch is normal and can actually be beneficial for your lawn. |
It can create a barrier, helping to retain your soil’s moisture and shield your grass roots from harsh elements.
However, if it is left to build up, that is where lawn thatch can become an issue for your lawn’s health.
Too much organic matter will start to suffocate your lawn, preventing air, water, and nutrients from reaching your grass roots.
It can also dry out the soil, forcing the grass to grow roots into the thatch, creating a spongy and uneven lawn.
What causes thatch?
Now that you are aware of how thatch occurs in your lawn, it’s time to look at what factors can contribute to its build-up.
Understanding what causes excessive thatch can help you identify potential issues earlier and take proactive steps to manage and prevent it.
Here are some of the most common factors that lead to thatch growth:
- Over-fertilisation. Applying too much fertiliser to your lawn, nitrogen-rich ones, in particular, can cause your grass to grow too quickly. Fast growth does not allow time for the older grass to break down properly, resulting in a build-up of dead grass and organic matter
- Soil compaction. Compacted soil prevents air, water, and soil from reaching the roots of your grass. Water can often be left to accumulate on your lawn, creating the perfect damp conditions for thatch to accumulate
- Overwatering. Similarly, overwatering your lawn can cause waterlogging which can hinder air circulation in the soil. Too much moisture and lack of air can prevent thatch from breaking down naturally, resulting in a build-up
- Pests and diseases. Common garden pests like insects and grubs enjoy feeding on lush grass, while diseases can cause damage to grass blades. Both can disrupt the decomposition of organic matter and debris, allowing them to take over
- Improper mowing. Not mowing your lawn enough means the grass will continue to grow taller, causing dead clippings to accumulate, contributing to thatch-build up. Similarly, if you cut your lawn too short, it can become stressed, which slows down the natural decomposition of organic matter and debris. Always remember to never remove more than one-third of grass per mowing session
- Grass type. Different grass types can be more prone to thatch than others. Grasses like Kentucky Bluegrass and Creeping Fescue grow rapidly, producing more organic matter that contributes to thatch build-up if not dealt with effectively
How do you get rid of excess thatch?
Excess thatch can cause significant issues for your lawn’s health, so it is best to take action as soon as possible.
In addition to suffocating your lawn, excessive thatch build-up can contribute to poor root development, increase susceptibility to diseases, and reduce resilience against stress factors like drought and foot traffic.
The most important lawn care practice to carry out when it comes to thatch removal is scarifying.
Scarifying is the simple, yet effective, process of removing organic matter, moss, and other debris from your grass.
The process of scarifying is more intense than dethatching your lawn, making it ideal for lawns with a significant build-up.
Scarifying is typically carried out using a thatching rake for those with smaller gardens or a scarifying machine for those with larger lawns.
Do not be alarmed by the amount of matter you are lifting from the grass, as scarifying allows you to delve deeper and remove more than just the surface layer of thatch.
Should I dethatch or scarify?
Dethatching is often confused with scarification, and although both processes involve improving the health of your lawn, they are different.
If your lawn has a light to moderate layer of thatch, then you may want to consider dethatching.
Dethatching is a gentler method that requires a rake or electric dethatcher to break up and lift thatch from the surface of the soil, allowing nutrients, air, and water to reach your grass roots.
However, scarifying is a more vigorous process that is ideal for those lawns with a heavy build-up of thatch.
Scarifying can also be carried out using a rake or electric scarifier, but it can break up compacted soil, remove moss, and stimulate the growth of new grass shoots.
It can be easy to confuse the two, but generally, if your lawn has a light layer of thatch, we recommend dethatching; if it’s excessive, opt for scarifying.
What time of year is best to dethatch a lawn?
The best time to dethatch your lawn is when it is actively growing.
However, this can depend on your grass type, i.e. whether it is a cool-season grass or a warm-season grass.
| Fast Facts Warm-season grasses should ideally be dethatched in late spring through early summer, while cool-season grasses need to be dethatched in early spring or autumn. |
Try to stick to these timings as best you can; otherwise, you may risk causing unnecessary stress and damage to your lawn.
It is important to note that your lawn may not need to be dethatched annually, but rather when you start to notice signs that your grass has too much thatch.
These signs can include:
- Soft and spongy texture
- Water pooling on the surface
- Poor grass growth
- Presence of pests and diseases
- Compacted soil
- Bare patches
- Yellowing grass
Will grass grow back after dethatching?
Yes, grass will generally grow back after dethatching your lawn with the right care and attention.
Do not worry if your grass looks stressed and thin after dethatching; it is completely normal and part of the process.
To ensure that your lawn makes a full recovery, you should:
- Remove any remaining thatch from the lawn
- Water deeply and infrequently to promote root growth
- Apply our expertly blended Perfect Prep Fertiliser
- Resume regular mowing once the grass has started to grow
How do you prevent thatch in your lawn?
Preventing excessive lawn thatch does not have to be difficult; in fact, it could not be simpler when following a month-by-month lawn care calendar.
By sticking to a schedule, you can ensure that you are completing core lawn care tasks in line with the seasons, which will contribute to your lawn’s overall health and prevent thatch build-up.
| Top Tips We recommend carrying out the following tasks to reduce the risk of excessive lawn thatch: – Aerate your lawn. Carry out this process to relieve soil compaction and allow nutrients, air, and water to reach your grass roots. It can also break up layers of thatch, preventing them from building up. The ideal time to aerate your lawn is in early spring or autumn for cool-season grasses and late spring or early summer for warm-season grasses – Fertilise correctly. Ensure that you are applying fertiliser as and when your lawn needs it. Over-fertilising your lawn can cause rapid, yet weak growth, while under-fertilising can leave your lawn stressed and a target for disease and pests. We offer a range of fertilisers to suit the seasons, including our Fertiliser – Summer Shield for the warmer months and our Fertiliser Winter Wellness for the harsher months – Mow properly. Maintain a regular mowing schedule and avoid scalping your lawn. Cutting your grass to the correct height will ensure that the grass clippings are small enough to decompose and not contribute to lawn thatch. In addition, make sure that you keep your mower blades sharp to avoid blunt cuts, which can put stress on the grass – Water deeply. Avoid overwatering by watering your garden deeply but infrequently. Following this routine promotes deep root growth, resulting in a strong and resilient lawn. Always pay attention to the weather; if rain is scheduled, you may want to avoid watering that day. Ideally, you always want to ensure that you are watering early in the morning so that your grass can dry throughout the day – Control lawn thatch. After mowing, make sure any grass clippings are disposed of in your compost bin. In autumn and winter, leaves can fall more frequently onto your lawn; you will want to keep on top of removing these as they can contribute to thatch build-up – Monitor your lawn. It might sound obvious but regularly monitor your lawn for signs of stress or thatch so that you can catch and address the problem more quickly |
Ready to take control of your lawn?
Thatch is a natural part of your lawn; however, excessive build-up can cause significant problems for your lawn.
Understanding what causes thatch build-up, the signs, and how you can remove it effectively can help you address the problem while keeping your lawn healthy.
In addition, prevention is key to letting thatch take over, so following a good schedule is essential for maintaining a healthy lawn all year round.
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