Many homeowners trying to get rid of moss in the lawn fail to realize that moss plants are an indicator that you currently have less than ideal conditions for growing grass. In other words, this weed is not the cause of your problems, but an effect.
The potential causes behind the problem are:
- Low soil pH
- Lack of necessary nutrients in the soil
- Poor drainage
- Excessive shade
Consequently, you have to understand that the job of getting rid of moss (permanently) has only just begun when you remove the particular patch of moss growing in your lawn at the present time. You must follow up that initial removal with some investigative work, to determine why moss would grow in the area to begin with, in spite of your attempts to grow grass there. If you fail to discover which of the potential causes behind the problem applies to your lawn, a new patch of moss will simply take the place of the old one.
Firing the Initial Salvo
So to begin, how do you get rid of the moss currently growing in the lawn? Well, since moss is shallow-rooted, you may be able simply to rake it out. But if you do need to apply an herbicide, take note that there are both chemical and organic (or "green") options. Among the latter, I've heard of baking soda being used, as well as soap (both Safer soap and the type of soap you use to wash dishes).
For example, some people recommend filling a garden sprayer with 2 gallons of lukewarm water and mixing in a box of baking soda. I've heard others mention mixing dishsoap (Dawn Ultra seems to be the preferred product) and water in a garden sprayer (2-4 ounces per gallon of water).
But again, such efforts will yield only a temporary benefit. For long-lasting success, it's critical that you conduct an investigation into the root cause or causes of the problem.
How to Get Rid of Moss: Finding the Root Cause
A great way to begin your investigation is to send a sample of your soil in to your local cooperative extension so that they can test it for you. Tell them you're trying to get rid of moss in a lawn and indicate that you need to find out what your soil pH is and whether or not your soil contains the necessary nutrients for growing a healthy lawn. This way, you can kill two birds with one stone: the root cause of your problem could be either (or both) of these soil-related issues.
The presence of moss can be an indicator that your soil's pH is overly acidic. If this is the case, you will need to apply lime to "sweeten" the ground. If the ground lacks the nutrients required for lawns to be healthy, you'll have to amend the soil and then fertilize the lawn on a regular basis (with compost if you wish to stay organic).
If your soil under your lawn does not drain very well and retains excessive moisture, this condition, too could invite moss. What's a good indicator that you have a drainage problem? Well, a type of soil with high clay content should send up a red flag. Water tends to percolate slowly through overly clayey soils, and that can lead to puddling. Happily, there's a very simple test you can conduct to determine what type of soil you have. Of course, if you remember seeing standing water somewhere on your lawn after a spring rain, that's all you need to know to conclude that you have drainage issues in that area. If clay is the source of your problem, amend the soil (e.g., with humus) to make it more friable.
Poor drainage could be due to any of a number of factors (clay content in the soil is only one possible factor). If the lawn receives a lot of foot traffic (as when children play on the lawn frequently), your problem could be soil compaction, for which the recommended solution is lawn aeration. When you should aerate depends, in part, on the type of lawn grass you grow. Aerate cool-season grasses in early fall and warm-season grasses in mid-spring to early summer.
Some homeowners intent on getting rid of moss really need to be focusing on getting rid of thatch. A thick layer of thatch can prevent water from penetrating properly through the soil. The process of removing thatch is called "dethatching."
In some cases, poor drainage will have to be addressed by re-routing excess water. French drains are often installed for this purpose.
Finally, getting rid of moss in a lawn can be a matter of addressing the issue of excessive shade. At least this problem, unlike the others discussed above, is intuitive: even total landscaping novices understand the concept of "shade." There are two angles from which to tackle the problem:
The second approach requires some explanation. The fact is, moss is opportunistic and will sometimes fill in lawn areas left bare because the grass variety you've chosen is ill-suited to shady conditions. The solution to your problem of getting rid of moss may be as simple as switching grasses.
Indeed, as with battling other types of weeds in the lawn, often the best defense is a good offense. Healthy grass will crowd out weeds. Instead of asking, "How do I get rid of moss?" a more apropos line of questioning may be, "How can I make my lawn greener?"