Dealing with moss.

Over the course of the 2020 mowing season I noticed a number of lawns with moss problem. For some moss is just another patch of green among a sea of weeds, grass, and whatever will grow. However, moss is a sign of an unhealthy lawn.

There can be a number of reasons why moss might grow and thrive on your lawn such as excessive shade, poor drainage, irregular grass cutting, poor soil fertility, and high acidity (low pH) to name a few.

When the soil becomes too acidic the grass will struggle to grow and plants and weeds that prefer acidic soil will thrive. According to Scotts healthy lawn will grow best at a pH level between 6.0-7.0. Moss on the other hand prefers a pH of 5.0-5.5. The only way to be certain if you lawn suffers from low pH is to have a soil test done, but moss is often a good indicator of high acidity in the soil.

Moss will tend to blanket the ground making it difficult for grass to grow and almost impossible for grass seeds to make contact with the soil and germinate. If high acidity is in fact the cause, applying dolomite lime, which can be found at most garden centers, can help balance the pH level in the soil. Dolomite lime is not a moss killer, it simply helps balance the pH level of the soil making your yard less favourable for moss.

Removing moss is an easy and effective way to begin restoring your lawn, however, without addressing the underlying reasons that caused the moss to grow it can be a short lived remedy. Raking or even dethatching your lawn is a good way to remove moss.

As mentioned previously, a soil test is the only accurate way to determine if your soil's pH is out of balance. Assuming a soil test indicated that low pH in my yard and I wanted to get rid of the moss and restore my grass I would remove the moss by dethatching and raking up the moss. I would then apply the appropriate amount of dolomite lime as determined by the soil test. Next, I would top dress my lawn with nutrient rich top soil or manure. Finally, I would seed with an appropriate seed blend for the climate and sun/shade condition where I live.

Of course any other issue such as poor drainage would have to be address if that were the case, but removing the moss and seeding is only half the battle. Proper lawn maintenance is always the best way to prevent an unhealthy lawn. Regular fertilizing, regular grass cutting, reseeding bare patches in the lawn to prevent weeds from germinating in those areas, and aerating and dethatching as required go a long way to keep your lawn healthy.

A lush and thick lawn is not a one time thing, but an ongoing effort.