If you have moss on your concrete, then you will want to read this guide to learn how to remove it and prevent it from coming back.
They say, “A rolling stone gathers no moss.” That’s great philosophical advice. But it is useless when it comes to your property’s concrete and paving stones.
If the concrete and paving stones around your home are anything like mine and don’t roll, then the odds are that at some point those features have been covered with moss.
Today, you will learn the conditions in which this age-old plant loves to grow. Then you will learn how to remove it from concrete driveways and from in between pavers and the tools necessary to do so. And lastly, you’ll find out how to prevent it from growing back.
Ideal Conditions for Growth
Moss is a non-vascular plant. That is a scientific way of saying that it has no roots.
Instead, it uses tiny threads called rhizoids to anchor itself to the concrete and pavers around your home. These rhizoids firmly attach the plants’ body to the concrete and allows it to absorb water and grow on the surface.
To prevent itself from drying out, moss requires a moist and sheltered environment. This moist habitat will allow water to absorb through the rhizoids.
Concrete and pavers are made of porous materials that allow the rhizoids to anchor in areas that other plants cannot.
In addition to the physical structure of concrete, some species will grow based on the acidity of what it grows upon. Certain additives in concrete and cement mixes can make the surface more acidic. This acidic environment is another reason moss tends to grow on concrete and paving stones.
There are a few different methods to remove moss. Depending on the method you choose to get rid of them, here are some of the tools you will need:
There are a few different methods that you’ll learn about below that will require you to dissolve and mix some different chemicals. Obviously, the spray bottle will be used to disperse the solution onto the unwanted growth.
A chemical mixture can be caustic and dangerous. It’s always good to be prepared with rubber gloves and put safety first.
Since rhizoids act as anchors, you will need a sturdy tool to efficienty remove them. A wire brush is sturdy and built to endure the tougher phases of the job.
Also, these wires have some flex built into them. That will make brushing out the cracks in your sidewalk and in between the pavers easier.
The moisture that accumulates in moss can sometimes give it a decent amount of heft. A flat-head shovel will make removing it or picking it up easier on your hands and back.
Use the push broom to sweep up any leftover debris after you have scraped with the wire brush.
Use a sprayer attachment on the end of your garden hose to clean up if you’ve decided to remove the moss by hand.
A power washer is the ultimate removal machine. It comes in handy in a couple of different ways. And it cannot be used without the aforementioned hose.
Removing It From Concrete and Asphalt Driveways
I know that, at face value, removing moss from concrete surfaces seems to be an easy order to fill. However, in truth, it can require a little patience on your part to do it correctly.
Here are the different methods you can use to do this job the right way.
Method 1: Boiling Water
Prepare some boiling water. Then carefully pour the boiling water over the entire area. This will soften up the moss.
Scrub it with a wire scrub brush until you have removed it completely. Sweep up the debris with a broom or wash it away with a water hose.
Of all the methods, this is the most environmentally friendly.
Method 2: Household Bleach
For this method, you first need to don old clothing and your rubber gloves.
Combine a mixture of 1 part water and 1 part bleach into your spray bottle. Spray the affected areas with the bleach solution. Allow the bleach solution to soak into the moss for 30 seconds.
Use a scrub brush to scrape tit off of your driveway or sidewalk. Spray away the debris with a water hose, or pick it up with a shovel and bag it.
Be careful not to accidentally coat any plants or grass you intend to keep as bleach is a non-selective killer.
Method 3: Baking Soda or Agricultural Lime
Sprinkle the baking soda or agricultural lime onto the moss. These basic powders will work to neutralize the acidic conditions that it thrive in.
Let the baking soda or agricultural lime sit for 24 hours. Scrape away with a stiff brush and clean the area with water and a cleaning solution. Carefully sweep it up and dispose of it.
Method 4: Vinegar
You can try pouring full-strength vinegar onto the moss to remove it. Allow the vinegar to sit for ten minutes. Then, use your stiff brush to scrape it away and a pressure washer to clean the area.
Reapply vinegar to the affected areas if it is necessary.
Method 5: Ammonium Sulfamate
First, you need to put on appropriate safety gear as this a hazardous chemical. Ammonium sulfamate can be used as a foliar spray to control woody plants. It is not easily found in many garden supply centers because of some of its toxic qualities. It is also used as a compost accelerator and a flame retardant.
Ammonium sulfamate is usually applied using a sprayer or watering can. Apply to the moss growing in areas of the driveway and walkways around your home.
Avoid spraying any other vegetation as it can prove harmful. Use a power sprayer to wash the clumps of debris from your pavement or patios after the chemical treatment.
Carefully follow the directions for application that come with the product. The directions will provide you with more information and a safe overview.
Method 6: Power Sprayer
Oftentimes, using power washing alone will clear areas of moss on your driveway and clean it up at the same time. If not, then you can circle back and use one of the methods above to loosen the rhizoids and use your power sprayer one more time.
Removing It from Paving Stones
You can use all of the same methods as listed above to get rid of moss growing on your paving stones.
The only additional tool you’ll need for the job is a garden or putty knife to reach into the spaces between the stones. Other than that, you can use bleach, baking soda, vinegar, commercial chemicals, or good old-fashioned pressure washing.
Tips for Prevention
You can use a couple of different tips to prevent moss from coming back around your home.
Open Up the Area
One way to prevent it from growing around your house is to open up the area, so more sunlight shines on it. Trim back shrubs and tree branches that are casting shadows onto the area.
Since moss needs a damp and sheltered environment to grow, by allowing the sun’s rays to shine in, you’re beating it to the punch.
Old navy ships used to line their hulls with copper sheeting to prevent barnacles from taking hold of the wood below the water line. You can use a similar tactic to prevent moss from taking hold as well.
Copper is a natural biocide. It’s essentially harmless to wildlife. In fact, it can be found in some of the multi-vitamins that we have in our medicine cabinets.
While putting down copper sheets around your patio is not really practical, you can spray a copper solution to coat it.
Copper sulfate comes in the form of blue crystals and can easily be found online. It dissolves easily in water.
Mix 1 ¾ pounds of copper sulfate per gallon of water. Two to three gallons should be enough to treat the average patio or area of paving stones.
Apply when the surface you’re going to treat is dry as a bone. This allows the solution to soak into the porous surfaces that concrete and pavers possess.
Apply it periodically to the surface because rain will wash the solution away.