Green, manicured lawns are a staple of most American homes. But sometimes, mowing and maintaining them may not be enough.
Moss can easily invade and thrive in lawns, weakening the grass and creating undesirable patches.
There are several potential causes of moss in your yard. However, the only way to solve the problem is by eliminating the weed and reseeding your moss-covered lawn.
How To Reseed A Moss Covered Lawn
Getting rid of the moss and reseeding your lawn can be challenging if you skip essential steps. Here’s how to fix this predicament.
What You Need
- Lawn mower
- Rake
- Iron sulfate
- Scarifier
- Aerator
- Grass seeds
- Seeder
- Fertilizer
1. Cut The Grass
As a plant, moss has a simple structure that is more similar to fungi and mushrooms than grass and weeds.
It reproduces by the production of spores, but it can also grow from tiny fragments of photosynthetic tissue left behind after branching or fragmentation. This is why getting rid of lawn moss is particularly challenging.
While moss is generally visible in turf-free patches, it can also grow in apparently healthy portions of the lawn.
Cutting the grass as short as possible can make it easier to remove the moss and treat the ground to prevent future growth.
Use the lawn mower on the lowest height setting. Since you’re going to reseed anyway, don’t worry too much about cutting it too short.
2. Rake Out Excess Moss
Since moss reproduces through spores, removing existing moss won’t get rid of it – think of it as trying to get rid of nasty mold causing brown spots on the ceiling and walls. Simply wiping clean surfaces won’t help.
However, it is easier to treat the cause if you remove as much growth as possible.
Use a rake to scrape away the moss.
Start from a corner of your lawn and rake along the edge. Make a U-turn when you reach the other corner and rake in the opposite direction, in parallel with the row you just cleaned. Continue with the back and forth until you’ve cleaned the entire lawn.
For the best results, the rows should slightly overlap. This ensures perfect moss removal.
Gather up debris into a bag and dispose of it or add it to your compost pile.
You must now do a second pass, working in diagonal rows this time – more or less a 45-degree angle compared to the first rows.
Top tip: If you have a large lawn, invest in a push-behind lawn rake or a 2-in-1 lawn rake and scarifier. You can choose from gas, electric, or battery-powered models, and they are as essential as lawn mowers for lawn and garden maintenance.
3. Apply A Moss Killer
Iron sulfate is your best choice if you want to get rid of moss on the lawn naturally. This substance works best on damp lawns.
To apply it, put on rubber gloves and sprinkle the powder liberally onto all areas of your lawn. Alternatively, use a lawn spreader. Make sure to apply it uniformly regardless of the application method.
Water the ground thoroughly immediately after application. Use the sprinkler system if you have one or a garden hose, making sure to cover the entire lawn. Leave it for at least seven to ten days.
Iron sulfate is not only a moss killer; it is also an excellent fertilizer most turf grasses and flowers love.
If you don’t want to use iron sulfate, use a chemical moss killer. Read the label before applying and follow all instructions to get rid of the moss.
4. Scarify Your Lawn
Scarifying a lawn is very similar to raking, but the process breaks up the thatch. Breaking up the thatch is crucial since the substrate promotes moss growth.
You can use a leaf rake or an automated scarifier. Follow the same steps you did for raking the lawn. Scarify twice for the best results, removing the debris between the first and second pass.
5. Aerate The Lawn
Your lawn is now almost ready for seeding new grass, but you should aerate it to promote grass growth.
The best way to do this is with a lawn aerator. These push-behind devices are either manual or powered, but they all have a roll with spikes that penetrate the ground and remove small bits of it to loosen it up.
Alternatively, you can aerate the soil with a pitchfork, pushing its spikes into the ground and pulling it out at a slight angle.
6. Overseed
With the ground prepared – and once four to six weeks from the moss killer have passed – it’s time to seed the grass.
Overseeding refers to the process of planting grass seeds directly into existing turf. However, all of the processes above will remove some of your grass, too, alongside the moss.
If the lawn looks awfully patchy, you should use four to eight pounds of grass seed per 1,000 square feet. If there are only a few patches, use about two to four pounds of seed per 1,000 square feet (or pro-rata if you have a smaller or larger lawn).
7. Aid Recovery
The last step is to get some fertilizer into the lawn. This step is particularly crucial if you remove a lot of moss since the soil might be poor in nutrients for the grass seedlings to grow strong.
Use a potassium-rich fertilizer for sandy soil (regardless of the type of soil you have) and sprinkle it across the lawn following the instructions on the package.
Until the lawn grows strong, wear smooth-soled shoes when walking on it and tread gently to prevent breaking the seedlings.
How To Keep Moss At Bay
Getting rid of heavy moss on your lawn is no fun, so you probably want to prevent it from growing and spreading again.
The only way to keep moss at bay long-term is by eliminating its cause and maintaining the lawn regularly.
Look for shady spots where moss might grow and try to bring some sunshine into the area, if possible. For instance, you could trim out tree branches or keep shorter hedges.
Moss thrives in moist, compacted soils. Aerate the lawn regularly, especially if you have clay soil. Aeration improves the health of your turf and also promotes drainage.
You should also check the soil’s pH and correct it if necessary.
As a rule of thumb, most turf grasses thrive in almost neutral environments (soil pH between 6.7 and 7.0). Moss likes acidic soils with a pH between 5.0 and 5.5. Correct the pH level with dolomitic lime or another pH corrector.
You should also avoid overwatering. Always give the grass about six to ten inches of water, early in the morning (never in the evening or at night).
The table below shows the watering frequency in days based on the type of grass:
| Season | Warm Season Grass | Cold Season Grass |
|---|---|---|
| Spring (Mar-May) | 4 - 14 | 3 - 7 |
| Summer (Jun-Sep) | 3 - 6 | No water |
| Fall (Oct-Dec) | 6 - 21 | 3 - 10 |
| Winter (Jan-Feb) | 15 - 30 | 7 - 14 |
Why Is My Lawn Full Of Moss?
There are three main reasons why your lawn is full of moss, climate, other environmental factors, and poor lawn care practices.
Climate
The climate in your area and the seasonal variations play an important role when it comes to moss growth.
Moss generally thrives in cold climate areas. While you can have lawn moss regardless of where you live, it is more likely to deal with it if you’re living up north.
Moss is also more likely to grow in years with cool, rainy summers, especially if the weather is cool and rainy in the other seasons, too.
Other Environmental Factors
Climate aside, there are other environmental factors that can promote lawn moss growth.
The orientation of your lawn is one of them. Moss is more likely to grow in north-oriented lawns or in portions of lawns that are shaded throughout the day.
The airflow in your yard also plays a role. If you have heavy, clay soil that retains moisture and poor air circulation across the yard, moss is more likely to grow.
Poor Lawn Care Practices
Negligence is the third and most common reason for moss on your lawn.
If you don’t mow your lawn regularly, if you mow it too often and too short, if you don’t aerate the soil, and don’t dethatch it each spring, you’re more likely to have a moss problem.
Leaving fallen leaves and mowed grass to sit and rot on the lawn from fall to spring is another common cause of lawn moss.
When Is The Best Time To Kill And Remove Lawn Moss?
The best time of the year to kill and remove lawn moss is the fall. This will give you plenty of time to treat the soil and monitor the results throughout the cold season.
If you notice moss starting to grow again after applying moss killer, repeat the first steps or contact a professional landscaper to help you out.
You can also get rid of moss in spring, although this is only recommended if you’re dealing with small and sparse moss patches.
Related Questions
Can you put moss killer and grass seed down at the same time?
While you can put moss killer and grass seed down at the same time if you want to, don’t expect any grass to grow.
Moss killer alters the soil pH and can affect the new grass seedling roots. This is why you should wait at least four to six weeks after the moss killer or iron sulfate.
Can you grow grass on top of moss?
No, you can’t sow grass seed over moss. All turf grasses need to be in direct contact with the ground to germinate. Sowing them on top of moss prevents the seeds from getting into the soil.
How long will it take grass to grow after reseeding?
Most turf grasses take about two weeks to germinate after sowing and about a full month after that to grow. However, some grasses can take up to 30 days to germinate.
Once all seedlings are grown (full coverage with no lawn patches), wait for about six to eight weeks for the lawn to become fully established until walking freely on it.
To End
Getting rid of and reseeding a moss covered lawn is a multi-step process that requires a lot of hard work and attention. If you want a thriving turf, it could be a good idea to let a professional deal with this issue.
Whether you reseed the grass yourself or plan to hire someone to do it for you, don’t forget that proper maintenance is crucial to prevent moss from taking over your lawn once again.