Lawns can benefit from thatch. Dethatching becomes a priority when the thatch grows to more than 1/2 inch.
Dethatching can be detrimental as it reduces the benefits of thatch. It is best to keep some thatch but not excessive thatch buildup at your turfgrass’ base.
What is Dethatching?
Thatch buildup is removed from lawns by dethatching. The accumulation of grass clippings, roots, stems, and dead grass blades between the soil’s surface and the base of grass blades is actively growing.
If left to accumulate over 0.5 inches, thatch can become a vegetative barrier and be detrimental to your turfgrass’ health. These adverse effects can be prevented by dethatching.
You can use tools like a hand rake or a power rake to dethatch your turfgrass.
The Pros and Cons Of Dethatching Lawn
There are many benefits to dethatching a lawn. This creates more air pockets within the thatch layer, which allows air, water, and sunlight to reach the soil easily. Thatch has many benefits for lawn soil. Dethatching, however, has its downsides.
These are the benefits of dethatching.
It increases sunlight penetration, air, and water.
Dethatching allows water and air to penetrate the soil and reach roots. The roots become more robust and more profound, improving turfgrass’s health. Grass with an extensive root system is more resistant to heat and drought.
It lowers your risk of getting sick.
Thick thatch can create anaerobic conditions where oxygen is not available. These conditions are ideal for the survival and growth of disease-causing fungal organisms like Sclerotinia homoeocarpa (cause of Dollar Spot in turfgrasses). The chances of fungal diseases infecting your turf are reduced by dethatching.
In thick thatch’s warm and moist conditions, some disease-causing insects/pests like book lice and mites thrive. A pest infestation can be prevented by dethatching.
It improves fertilizer penetration.
It acts as a barrier to the growth of plants. The barrier is removed by dethatching, which allows fertilizer to penetrate the soil more easily. Most turfgrass types are healthier and fill in quicker when fertilizer has been applied.
It improves herbicide penetration.
Systemic herbicides, which enter weed plants via their roots before being transported elsewhere in the plant, must first reach the soil to reach the roots. A thick layer of thatch is a barrier preventing these weed killers from entering the soil. This allows herbicides to get to the roots of weeds by dethatching.
It increases the success of overseeing.
The thatch is mixed with the lawn topsoil to create a pseudo substrate layer, which new grass seeds confuse for natural soil. Thatch isn’t as nutritious as soil. The result is that grass seeds germinating in thatch are not as healthy as soil and can die quickly. Removing thatch makes overseeing easier by allowing new grass seeds to reach the ground and grow in it.
These are, however, the cons to dethatching.
This leaves your lawn open to weeds.
It acts as a barrier preventing weed seeds from reaching the ground. It helps suppress weed germination. Dethatching turfgrass allows the weed seeds to grow in optimal conditions.
The soil can be dried out by dethatching.
It reduces the amount of sunlight and atmospheric heat reaching the soil. It slows down evaporation and retains soil moisture. The ground is exposed to direct sunlight and heat retention by dethatching it. This can lead to more evaporation. Drought/lack of soil moisture can even cause turfgrass to die.
Dethatching can dry out the soil. The soil can be drained more easily by dethatching. Excessive thatch can hold water from rainwater and irrigation water, which prevents water from reaching the ground. Aerating the dethatched areas can help balance water penetration and dethatch.
Frost vulnerability increases with dethatching.
Thatch keeps the soil warm and prevents cold air from reaching it during winter. Thatch makes a lawn less vulnerable to frost damage. After dethatching, the lawn is less cold-tolerant and more susceptible to frost damage.
Your lawn is at risk of turf injury when it is dethatched.
Incorrectly trimming a lawn with aggressive tools such as a power rake and a vertical mower can result in excessive turf injury. This is especially true for turfgrass varieties spread via stolons but not stolons.
The blade height should not be set too close when using dethatching tools. The tool’s blades saw through the runners above the ground, making it difficult to recover the turf.
Is it possible to dethatch wet lawns?
Technically, it is possible to dethatch lawns when they are dripping wet. You shouldn’t. Dethatching tools can cause lawn damage. Wet thatch can also clog power dethatching tools’ tines, making them less efficient and difficult. It’s better to avoid wet thatch.
Dethatching works best when the grass is just slightly damp. Lightly irrigate your lawn for two days before dethatching. This will ensure that the turfgrass is not too wet but still moist.
How to avoid thatch buildup?
Watering according to the soil’s pH and applying a liquid thatcher are the best ways to prevent excessive thatch buildup.
Some turfgrasses, like centipede grass, require very little water to thrive. Overwatering can make them more susceptible to developing thatch. This doesn’t mean you shouldn’t let the lawn dry completely. Soil needs moisture to decompose.
Remember to water your lawn well. Each week, we recommend that you water your property by one inch. Keep the soil moist to avoid waterlogging.
The lawn should be aerated.
Thatch is organic matter that has not yet been decomposed. Core aeration of lawn soil reduces thatch by reducing soil compaction and increasing microbial activity.
Thatch that has more soil bacteria decomposing faster is less likely to be harmful.
Monitoring and adjusting the pH of your soil
Sometimes, soil pH changes can lead to decreased microbial activity and thatch buildup. To prevent excessive thatch buildup, you should regularly monitor and adjust your soil pH. Lime can be added to acid soils to increase the pH.
Notice: The ideal soil pH to support soil bacteria involved in thatch degradation is 6.5. A pH lower than six will cause microbial activity to decrease.
Use a liquid dethatcher.
Although rakes or vertical mowers can be used to remove thatch, liquid dethatchers can be used while it is still thin to prevent it from building up. The biological and liquid dethatchers are made up of bacteria and enzymes. They speed up the thatch degradation process, preventing the thatch layer from becoming too thick.