Why is Moss Growing in My Lawn? Do you have patches of lawn where there’s moss growing instead of grass? You can easily rake up the moss, but it’ll come back again until you address the underlying cause for it. 4 Possible Causes for Moss Growing in Your Lawn & How to Combat it Moss could be a sign that your lawn isn’t getting enough sunlight, isn’t draining properly, or has soil that may need to be aerated. Stevechatterton / iStock / Getty Images Plus While you can get rid of moss by raking it up and using a moss killer, you still need to address why moss is growing in your lawn. Here are four possible causes of moss development: You may have a yard drainage problem. If you have compacted soil, excessive thatch, or your clay soil causes ponding on your yard after a big rain, you could end up having a moss problem.There are three reasons why water doesn’t percolate through the soil: Your soil is compacted - in which you should aerate your lawn to allow more water and oxygen to penetrate the soil, allowing for better drainage. There’s too much thatch - to remove it, you will have to dethatch your lawn, which will allow water to reach your soil instead of getting stuck at the thick thatch. Sitting water - after a big rainfall, if you have ponding that takes a long time to drain, you may have to think about re-routing water away from those areas. A landscape contractor will be able to give you recommendations on how to grade the area, or other solutions if necessary. You may have too many trees blocking the sun. If trees dominate a portion of your lawn, grass will have a difficult time growing because it’s not getting enough sunlight and air circulation. You can add more sunlight and air circulation by pruning back your trees. Follow proper trimming techniques to keep your trees looking beautiful as well as improving air circulation and sunlight exposure. The soil’s pH is too low. Grass grows best when the soil’s pH ranges 6 – 7. When the ground becomes more acidic, the grass won’t grow. Instead, you’ll have moss growing in its place. The solution? Get your soil tested. It’s better to get your soil tested through your county extension rather than buying a soil kit test. When you collect your soil samples, note on your paperwork to the extension service that you need your pH tested due to moss. Your county extension will give recommendations based on the test and the moss evidence. 4. Your soil lacks essential nutrients. Your grass needs nitrogen, phosphorous, and potassium, as well as many other minerals to flourish. If your soil lacks any of these nutrients, your grass won’t thrive, and moss will compete for space. If you are already getting your soil tested for pH, you can note on the paperwork to test for missing nutrients as well. You improve your soil’s lack of nutrition by adding organic compost and fertilizer to level out the nutrient deficiency.