Thatching Your Lawn

Lawn thatch is nothing but dead grass which forms a layer between the soil and new growth.   It can comprise of roots, debris which when it becomes excessive can actually strangle and retard the growth of new grass.  Since thatch cannot hold moisture, the soil becomes dry and unfertile.  Thatch becomes a store house for insects and diseases.  Thatch growth is also promoted by excessive Nitrogen from fertilizers (read article on `Fertilizers’). 

The presence of lawn thatch gives turf an uneven look, and once the new grass starts growing, it is very difficult to de-thatch.  Secondly, the thatch prevents fresh grass from getting adequate water supply as it forms a water proof layer choking the stem of the grass plant and preventing it from getting water from its roots.  With lack of adequate water supply, grass can turn an unhealthy shade of yellow and its sickly appearance will be compounded by all those pests which love to attack sick plants. 

Hence, a good understanding of thatching and de-thatching will ensure that your lawn looks great.

How do you recognize thatch?

That spongy looking messy tangle of dead leaves, grass, stems and roots is thatch.  But often it is difficult to tell the difference between thatch and weed.  To ensure that it is thatch, check the soil and try to push your fingers into it.  If you feel a push back or it is really tough to penetrate the soil, it is likely that it is thatch.

When to de-thatch?

The best season to de-thatch is autumn, as it is during autumn that plants are naturally shedding their leaves.  At this time, grass may soon recover and grow back.  However, in spring, the roots are firm and the grass is in a growth mode, and de-thatching becomes an impediment to its natural growth.

How to de-thatch?

If it is early stages, then using a rake will help. But if the thatch has really penetrated the soil and it is tough to wedge it out, then you will need to use a `de-thatcher’, which is a power rake.

The thatch hand rake is an easy option in the early stages.  With its knifelike teeth, it can drag out the thatch easily. 

Another option is the vertical mower which you can rent for use.  The vertical mower is very effective in bringing the thatch out of the soil and it is by far the most convenient option. However, the mower might end up mowing a bit of the healthy grass too, and hence, you will have to re-seed these areas (read article on `Seeding your lawn’).

Another alternative is `coring’ which is done by using machines called coring machines.  Coring machines create cores or holes in the ground as they drill out thatch.  The open holes allow moisture to enter; this helps in preventing further decomposition of any thatch that might still be buried underground. 

Once de-thatching is completed, it is wise to apply a soft layer of soil, which will help enable microorganisms to penetrate the ground and destroy any remaining hidden thatch.