Mulch vs Rock - Which is Better for Your Home Landscape?
People are asking us about mulch vs rock and which of them would be suitable for soil cover? Before we could answer this question, we have to know the type of soil cover you want like would you need it for aesthetic appeal or to benefit the plants in your garden? Basically, both mulch and rock have certain benefits to the soil, to the plants and also to give your home surrounding the aesthetic but rustic ambiance. But before we state some of the pros and cons of mulch and rock, let us tell you more about mulching and rock mulch first. 
Mulching is the process of covering the soil with organic materials that mainly come from different species or varieties of plants and trees to reduce evaporation, preventing soil erosion, moisture retention, weed control and providing nutrients to plants and trees. It can also act as a form of barrier to reduce the movement of water throughout the soil.
Rock mulch or stone mulch is also another form of mulching but as the name implies, you only use rocks or stones for soil cover which are inorganic and not capable of decomposing. You can commonly see these as decorative soil covers around fountains, palms, trees, or any large structures that need more pronounced aesthetic appeal. However, rock or stones are used not only to beautify but also to benefit the soil and plants. So here are the advantages and disadvantages of using organic mulch and rock mulch.
Pros and Cons of Organic Mulch
When it comes to mulch vs rock, organic mulch is always seen as the better choice with regards to the healthy growth of plants. But it also has some negative effects. So we start with the benefits:
Pros of Organic Mulch:
Promotes better growth in plants. Organic mulch when decomposed brings about so many macro and micro-nutrients into the soil which help the plants and trees to grow faster, bigger and more robust. It is also full of beneficial microorganisms that can enhance the decomposition of the organic matter present in the mulch.
Reduces evaporation. If the organic mulch has the right thickness and as it gets compacted, the better it can reduce evaporation and preserve water for the plants compared to the stones mulch which barely compacts at all. 
Prevents the growth of weeds. It may reduce about 50% growth of weeds while stopping new seeds from sprouting. The grown weeds are also much easier to pull out with organic mulch because mulch is looser than topsoil.
Can maintain the optimum soil temperature for the plants. It can keep the soil warm for the plants during winter and cool during summer.
Erosion control
It can hold up water about 80% of its volume thus it can serve as a good medium for erosion control. 
Cons of Organic Mulch
Needs regular replacement.
There are different types of organic mulch. Some can decompose in a year such as hay, grass clippings and shredded leaves while other forms take 1 1/2 to 2 years like wood chips, barks and tree roots. So depending on the mulch type, you still have to sustain the mulch on the ground like once or twice a year or as needed.
Can stress the plants.
There’s always the right thickness of the inorganic mulch to make it safer for the plants. Because unlike with the rock mulch that does not compact, once the compaction of organic mulch gets to more than 3 inches, there will be the build-up of heat underneath which can stress the plants. 
Should be applied at the right time.
The best time to apply a thin layer of organic mulch should be mid to late spring as these are the period when seeds begin to germinate. Applying too early may heat the ground and prevent germination. Applying too late like autumn to winter may not benefit the plants because of slow mulch degradation. The landscape should also be free of all weeds before mulch application to ensure a weed-free landscape.
Pros and Cons of Stone Mulch
Stone mulch is mostly preferred for landscaping purposes as these can create a more neat-looking and well-managed scenery. But like the organic mulch, there are also some corresponding benefits and disadvantages to it.
Pros of Rock Mulch:
Require only very little maintenance. Once you put stone mulch, you can leave them out there without the need for replacing them.
Less expensive.
Compared to organic mulch which you must add now and then, rock mulch will cost you more to buy them but once installed they retain their shapes for many years.
Resistant to wildfires.
Living near forested areas is safer using stone mulch for the yard. They can serve as fire breaks but remember not to plant trees like pine trees or eucalyptus which are easy to combust especially if your area is prone to forest fires. 
Fewer weeds grow.
Because seeds of weeds don’t have much soil to cling onto the rock mulch, most of them don’t germinate at all or if they grow are very easy to pull out because their roots are only holding on to the small amount of soil.
Resistant to strong wind. People living in windy regions are not advisable to use organic mulch because once it gets dry, most of it will be taken away by the wind and scatter it along the pavements. Rock mulch won’t move no matter how windy the environment could be. 
Best choice for rock and cacti gardens.
The stone mulch is best suited in these kinds of gardens to create an ambiance of a natural desert environment.
Serve as a good backdrop to the grass lawn. It can break the monotony of large grassy lawns and best to place around hedges and bushes or ornamental perennial plants.
Cons of Stone Mulch
Can become too hot during summer. With the temperature going up, the heat can be assimilated by the rocks and heat the plants’ surroundings. So it should not be placed around plants that are sensitive to heat. The soil can also absorb the heat from the rocks which can stress the plants and dry their soil quickly.
Not suitable for plants that need acidic soil.
Rock mulch can turn topsoil into alkaline soil because it is not retaining water unlike with organic mulch. So plants and trees that need acidic soil will not grow well when mulched with rock
Can prevent adequate branch rejuvenation on plants. Large rocks that are heavy and solid can prevent the proper sprouting of branches that normally comes from the main stems of some young plants. With rocks around the stem, these can cause unwieldy growth of these branches. So if you intend to use rocks around shrubs that you want to trim, put rocks only around old shrubs that grow branches on top. 
Difficult to remove. You may decide one day that you want to change your rocks and stones into luxurious garden grass and so you need to put on organic mulch. But the problem is, collecting the stones should be done by hand which is a very tedious job
When Rock Mulch a Better Choice?
Organic mulch is the way for healthier soil and better-growing plants. But sometimes we think about shifting to rock mulch because of many practical reasons. So when would you need to try using stone mulch? Rock mulch is a better option if there is a poor drainage system around your house especially if your area is flood prone. So it is better to have rock mulch to easily drain water from your yard and your plants. With mulch, even the water is gone, much of it will stay on the soil thus this can introduce soil-borne diseases to the plants. 
Another thing why we sometimes need to consider rock mulch is when you have some open areas where grass maintenance is difficult. For example, if the water is scarce in your area or you don’t want to spend too much on your water bill, then the use of rock mulch with river stones will enable you to cover up some of the barren areas on your lawns and can still produce a neat-looking lawn. 
You want to install a fountain or a statue in the middle of your lawn? Or do you want to set up a Japanese garden with the appeal of natural rock formations around the shrubs or near the bridge? Rock mulch can bring about a handsome and exotic appeal to this kind of garden. And if you like to have a more attractive-looking fountain, you can create a more refreshing aura if you’ll put some nice looking pebbles around it. Regardless of the size of your lawn or yard, if you can install a centerpiece like a fountain or a statue, this can instantly create a relaxing ambiance as water, rocks and greenery combined can give you a natural therapeutic process to relieve your stress.
Mulch Vs Rock - Which Are Preferred by Homeowners & Property Managers?
We asked people which among the mulch and rocks are their most preferred choice when it comes to maintaining their lawns and properties and we got varying but interesting responses. For some homeowners, they prefer the mulch because accordingly, this is the best natural form of fertilizer that can enrich the condition of the soil and improve the overall condition of their plants while keeping them always hydrated. They also prefer the greenery over the lifeless ground cover like rocks which only the organic mulch can offer. 
On the other hand, most of them also don’t like the maintenance needed with the organic mulch like the need for regular mulching and having to mow grass and prune ornamental plants more often as they get more nourishment from the mulch.
Then we asked some property managers about mulch vs rock and which of these can make a better appeal to properties. Accordingly, rock mulch requires only little maintenance while they keep the surrounding clean and tidy. It can also fit to any type of outdoor environment and can create crisp and contemporary charm around ornamental plants and garden decor. They also added that some property buyers can easily get swayed in buying properties with nice rocked landscapes with the perennial shrubs in the middle. So when it comes to choice, mulch is better preferred by the homeowners while for the property sellers, mulch and rock should go together to enhance the value of the property.
Types of Rock Mulch - Which Would You Prefer?
Did you know that there are different types of rocks for mulching? These rocks don’t contribute to the fertility of the soil but they can basically improve the landscape of homes and building surroundings.
So here are the 7 varieties of rock mulch and stones mulch that are used for landscaping and ground cover purposes. We also include tips on where to put them to serve their purpose.
Decomposed granite.
These are parts of the decomposed granite that are reddish-tan. They can provide landscapes a softer and rustic look and they are great around small and medium-sized trees. They also look better on garden trails and fit for xeriscape which are landscapes that do not need water for maintenance.
Pea gravel.
As their name says, these are pea-size gravel with about 1/4 to 1/8 inch in size. Their colors range from white to brown and they are often used on driveways and as fillers between stone pavements. If you want to have mulch rock to control weeds, the pea gravel stones are a good choice because of their small size and they compact easily. 
Crushed granite gravel.
These are larger than the decomposed granite gavels. It can offer a nice, organic look on any yard or garden and these are better if you want to have a smooth transformation between pathways and garden plants. 
Lava rocks.
These are dried and crushed parts of lava and they have pretty bold colors that can provide an explosive accent to any landscape. Best to use for areas with arid climates as it can absorb heat in the daytime and release it once darkness settles in. Very lightweight, these rocks are easy to spread. 
River rocks.
You probably know what river rocks look like. These are what they call the live rocks because they are heavy, often rounded and flat, have smoother surfaces and vary in colors. They are best for garden borders or around short palm trees and they always look alive. You can also install them along free-flowing water or right along the garden drainage. 
Flagstone.
These rocks are large, wide and flat and are better be used as stepping stones, for garden paths and on walkways along the landscape. 
Marble chips.
These stones are the classy types of rock mulch. They look best around container gardens and gardens with elements such as pots, statues, and decors. However, don’t use them around plants that need acidic soil because these stones mulch are known to change the ph level of the soil they are laid on. 
You can buy most of these rocks and stones at Amazon in small bags and you can even see their descriptions, how to use them for better accent and where to use them to maximize their features along with your plants and landscape.
My Conclusion
So here are the things you should consider before taking on organic mulch or rock mulch. First is the cost, stones mulch is generally more expensive than mulch though it doesn’t break down and no need for annual replacement. Second, think about what your soil needs. Remember that rocks are all about ground covers, beautification, and low maintenance but your soil and plants don’t get anything from it. Third, if your landscape has a lot of trees in it, rock mulch would not be a good idea as it can accumulate fallen debris that are hard to clean out. 
Fourth, if you plan to install rock mulch along your flower beds, think twice first. Flowering plants will not grow well with rock mulch although the drought-tolerant plants will thrive. So always consider the type of plants you have before deciding to use stones mulch. Finally, if you are to compare mulch vs rock in terms of choice, why not consider using them both. You can search for landscape designs on the web with mulch and rocks combined so you’ll have the option for a better-looking yard by putting a twist in it.
For our next blog, we will be talking about blowing mulch which is the process of blowing mulch into the soil and around plants using trucks loaded with machines that carry mulch for easy application.
