Aerating and dethatching a lawn

And how to have the best lawn on the block without them

Spring is here, the snow has long melted, lawns are looking greener and people are thinking of how to achieve the perfect lawn. You, or someone you know, may be aerating, or dethatching a lawn to improve its look. I had one friend tell me over the weekend “I need to aerate, because I was told that would help my lawn”. I told her not to waste her time. 


In the short term, aeration is a great way to improve the oxygen that the grass roots are getting. However, in the long-term, it becomes more damaging by impacting the microbiology of the lawn. If the soil is compacted or has poor drainage (both possible in urban or suburban settings), the grass won’t grow well. Aerating once will have a short term effect on the lawn, but repeatedly exposing microorganisms to the air can be detrimental. If these microorganisms aren’t replaced the quality of the lawn will deteriorate. If the goal is to improve air pathways to the roots, there are other ways to do that. But not by dethatching.


Thatch is a mat of un-decomposed rhizomes, stolons and crowns at, or near, the soil surface1. Too much thatch can smother the roots, some thatch can protect the crowns from being crushed by foot traffic. Dethatching is the process of ripping thatch out of a lawn to improve air flow to the grass roots. So how much is enough? We can let nature decide on that. 

Adding microorganisms to your lawn can initiate a process to break down thatch and create air pathways in the soil for oxygen to reach the grass roots all at once. Effective microorganisms, compost and compost tea all contain the necessary microorganisms to do the hard work. Once these microorganisms are present in sufficient numbers, they can work their magic to a green and healthy lawn – while you sit back and enjoy the sunshine. Visit the online store to find some products that will help your lawn.

As for my friend, it’s likely she’ll benefit from some of the next batch of compost tea. Prepared with high bacterial compost, it should be exactly what her lawn needs.  

  1. Hermary, H., (2023) Thatch [Lawns]. 

Published by juliamdupuis

Green Angel Sustainability Consultant. Environmental Chemist. RRU MEM Graduate.

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