Last Updated on October 29, 2021 by Grow with Bovees
Have you ever wondered why some plant owners and cultivars add a selection of rocks to the top of their plant pots?
Putting rocks on top of potted plants has not only shown to be beneficial to your greens but also adds a lovely modern look to indoor houseplants and even outdoor garden plants.
Some benefits of placing rocky materials in your planter include the reduction of flies around your shrubs, it creates lovely decoration, it improves water retention and more.
Some plant owners and garden experts may recommend top dressing your planter whereas others don’t think it’s a great idea.
Regardless of whether you choose to make use of stones as a dressing, always make sure that your shrub is planted in a proper soil mix with perlite.
It needs to be well draining potting soil and if it is grainy enough, drainage will be even better and airflow will be sufficient.
Continue on to learn about the benefits rocks have to your potted lovelies and also get a few tips on how you can make this a decorative addition to any plant container.
Benefits Of Mulching With Rocks In Pots
Let us start off by taking you through the positive aspects of using rocks in your planters.
Adding rocks on the top of potted indoor plants gifts them with a certain cosmopolitan look which makes them fit in and match with other modern decorations, hence why rocks are used for aesthetics in many cases.
This decorative rock covering is in fact commonly used in cactus & succulent gardening. It gives any pot a finished and neat look.
Color Of Rocks
In the case of using rocks for a decorative aspect, white is the preferred color to use. The white color of the rocks creates a beautiful and fitting contrast together with the amazing shades of green that most shrubs provide.
When creating ornamental gardens such as beautiful fairy gardens, for example, beautiful different colored stones will be used instead.
When choosing to use rocks of color to place on the top of your plant pots, be careful of the type of rock that you choose to cover the topsoil.
We say this because when watering certain types of stones, they can trickle limestone which then naturally seeps into the soil of your shrub.
This limestone dripping may cause the pH of the soil to rise.
This, in turn, is quite harmful to your greens as it hinders the absorption of important nutrients through the roots, which ultimately causes your indoor plants leaves to turn yellow, wilt and die.
Two types of stones that are a great choice when planning on adding them to your pot are glazed rocks and crushed gravel.
Do you have pets in your home that are very interested in interacting with your household plants? If so, then pebbles or gravel are great to use.
Adding stones to your pot creates a barrier to the soil below, and thus prevents the curious interaction of pets with soil, which may cause some health issues if not avoided.
Potting mixes and soils contain a certain amount of constituents that are produced to enhance the growing needs of container plants.
These ingredients may be harmful to your pets when ingested, causing an array of diseases and problems. We therefore recommend that you shoo any pets away when they attempt to interact with or even eat potting soil.
Water Loss & Moisture Levels
Topsoil that is covered with stones or gravel will naturally achieve a reduction in temperature due to the shading effect of the rocks.
This causes reduced water evaporation into the air, which in turn will reduce the frequency of having to water your shrub.
Drafts & Winds
A coat of stones will act as a shield to keep any cold drafty winds from removing moisture from the soil when blowing past.
Tumbled glass, interestingly enough, has the same effect.
How annoying is it when water splashes out from your pots every time you go about watering your succulents? Having to go back to mop up splashed soil from the floor?
Adding stones to the top of your pots is the solution. The pebbles again act as a barrier and when irrigating your shrub they will break the force of water, preventing it from splattering onto the floors and inner sides of the pot.
It also prevents potting soil from getting onto the leaves of indoor plants.
Less splashing of water, means less water being released into the atmosphere, which in turn means reduced water loss for your plant.
Fungal Prevention & Weed Prevention
As a plant lover, you might have heard about fungus gnats. They are small flying critters that resemble the appearance of mosquitos. Fortunately, their life cycle is short, but they do carry harmful fungi which like to feed on plants.
These plant-eating fungi are known as Phytophthora and Pythium.
Moist soil conditions and areas of decay are the perfect ground for fungal gnats to grow and thrive. These conditions often feature in the topsoil of succulents and mature plants, and this is also where gnats lay their eggs.
Placing rocks over the top layer of soil in plant containers hinders fungus gnats from crawling into the first quarter inch of the soil where they like to breed.
Rocks alone may not be a great candidate, though, make sure the soil is covered in a layer of garden sand before adding the stones.
The holes or gaps between the rocks create pathways which will allow critters to slip through. The sand will not hold water but rather allows the water to drain without mimicking breeding grounds for gnats, making room for healthy indoor plants and succulents.
Much like the prevention of fungal gnats, mulching the topsoil with pebbles also hinders the onset of weed growth from your container plants.
Knowing The Difference
When cultivating different hybrids — during a potted plant project, for example — that look similar in appearance, adding pebbles of different colors to each pot, will easily help you tell them apart.
Dress plants, especially when they are still young and small succulents.
Disadvantages of Plant Rocks
Much like with everything else, mulching with rocks also comes with some disadvantages.
Continue on to learn about why you should be a bit wary when placing rocks on top of the soil in your plant pot.
Outdoor container plants that are located in areas of lots of sunlight, for example outside, on a balcony or porch, or plants that are standing underneath artificial lights, may be at risk of overheating due to the stone mulch.
Too much or prolonged sun or light exposure to the rocks will cause the stone mulch to start heating up.
The heat will start radiating from the pebbles and start making its way to the close surroundings of the plant. Too much heat will cause plant stress.
Bigger amounts of heat also promote evaporation, which means that a lot of water will leave your plants potting soil, eventually causing your shrub to wither due to being too dry.
Even though some weight on top of the soil will hold top heavy or a heavyish plant steady, be aware of the amount of rocks that you place on top of your plant container’s soil.
The more pebbles you add, the more wait is being exerted on the soil, which will then start compressing the soil.
Compressed soil makes for too dense soil which can lead to waterlogging due to lack of drainage after giving your plant water. This in turn makes for too wet soil.
Dense soil also means a decreased number of oxygen pockets inside the potting soil. Inadequate aeration in the soil, leads to the suffocation of plant roots which will eventually cause your shrub to perish.
Rocks Below The Potting Soil & Drainage Holes
We are all aware that plant soil needs good drainage. It is said that if you place stones below your pot, it will improve drainage and even aid in sufficient drainage of excess fluid.
Simply take a pebble tray and place some rocks into it. Then fill water into the tray and sit your plant pot and saucer onto the tray.
You might ask yourself how much water do you add? The idea is to make sure the water level in the tray is about halfway covering the rocks.
You don’t want to create a risky environment for your plants’ roots where they sit in water over long periods of time. This can be very harmful to your beautiful plants as it may cause a condition called root rot.
Regardless of making use of the pebble tray method, always make sure that the planter of your indoor plant has a drainage hole in order to increase drainage. When watering this will ensure adequate drainage of excess water.
Arranging Indoor Plants
Repotting your container plants once every few seasons is helpful in maintaining good plant health and good growing plants.
If you feel it’s too soon to change pots, simply add a layer of new rich gardening dirt mixed with organic nutrients — a mix with perlite for example — or some potting soil mix which is well draining to freshen up the soil. Another thing that is great for growth promotion is feeding your shrubs with some houseplant fertilizer.
Sprucing Up Indoor Plants
Potted plants can look quite boring and unattractive with only dirt in them.
As mentioned above, by adding a layer of rocks to your entire pot, you can easily spruce up your indoor container plants. Choose between plain black gravel or gravel of different colors to make for a more decorative look.
Personal Tips For Your Potted Plant & Top Dressing
Simply take a dirt mix of small gravel from your driveway and cover all the soil with a thin layer of it. This layer of rocks will create grounds for water to drain into the soil and seep through the roots while at the same time keeping the potting soil in its place while watering.
You can even take your decorative plant project to the next level by adding a few different crystals and gems to the pot. It is a great way to put your rock collection on display.
If and when you decide to go ahead and start a decorative gardening potted plant project and go about dressing your plant — whether you choose to do so with a cactus garden or a regular indoor or outdoor potted plant garden — be sure to have the following materials at hand to start with:
- Planting & garden materials
- An indoor plant
- A large plant container or pot
- Some garden dirt mix, potting soil, potting mix with perlite
- Small to medium-sized decorative stones, gravel or porous clay pebbles
- Polished rocks of color, such as crystals or quartz and colored pebbles
With the above listed materials, you should easily be able to decorate any pot, adding an ornamental modern look to any plant collection and room.
Conclusion of Covering Potted Plant Soil With Rocks
There you have it, fellow lover of plants. You should now have a pretty good idea why and why not to add rocks to the top space of your potted plant.
I suggest that you go ahead with this easy beautification of your container plants. Whether it be for aesthetic reasons, preventing the loss of water and fungal gnats or keeping house pets and kids away from your pots’ space.
These are all good reasons to go ahead with adding pebbles to your potted plants.
Just remember to keep an eye on waterlogged soil due to on site compression and heat radiation due to heated up rocks, and you will be good to go.
Good luck and, most important of all, just have fun! Happy decorating!