Putting Rocks on Top of Potted Plants

Putting Rocks on Top of Potted Plants Image

Putting rocks on top of potted plants serves different purposes. But should these rocks be below or on top of soil particles?

Well, putting rocks above potted plants’ soil has several benefits. Some of the benefits are root protection and hydration in moist soil. Further, decorative rocks boost your Garden’s aesthetic value.  

So, in this article, we’ll discuss whether rocks on potted plants are ideal. Also, we’ll discuss the various rocks one can put on top of potted plants.

Can You Put Rocks On Top Of Potting Soil (Of Potted Plants)?

Yes, you can put rocks on plant pots since they’ve got several benefits. Moreover, these rocks do fit the following:

  • Outdoor plants
  • Indoor plants

Further, rocks covering topsoil protect your indoor plant against the following:

  • Soil splashes on the foliage.
  • Soil erosion.
  • Pests.
  • Weed.

Also, as we said earlier, these rocks improve your Garden or plants’ aesthetic look. But it would help to know the disadvantages of these rocks too. And that’s before putting them on your potting soil.

But don’t worry. We’ve also listed some alternatives to rocks, like rubber and mulch.

How to Put Rocks on Top of Potted Plants?

There’s more to covering a potted plant using rocks than just tossing some gravel in the plant pot.

  • First and foremost, pick a plant container with drainage holes at its bottom. That’s because drainage holes prevent moisture buildup at the container’s bottom. Further, in preventing moisture buildup, they also prevent root rot. You can drill a drainage hole if the plant container has none.
  • Apart from picking a suitable plant container, it would help if you had certain rocks. Otherwise, picking random rocks may negatively affect the soil pH. Thus harming the plant. For instance, limestone rocks may raise your soil’s pH. And in the worst scenarios, some stones may introduce organisms that may eat potting soil.

I recommend picking glazed rocks if you’re after aesthetic appeal. Other suitable rocks are crushed gravel, brick chips, and river rocks. Also, sand is a fabulous top-dressing material. They allow moisture to move to the roots and prevent a bug from laying eggs.

  • Research your plants’ suitable soil acidity before top-dressing them. After doing the soil topdressing, retake the soil pH often to prevent plant harm.
  • Finally, put a layer of your rocks on the soil. When doing that, don’t overfill your plant container with stones. Create some holes within the potting soil to allow oxygen circulation. That’s so since compressed soil won’t drain well, decreasing oxygen levels.

Why Put Rocks in Potted Plants?

Putting Rocks on Top of Potted Plants Image

Adding aesthetics using decorative rocks for indoor plants

Broken and rounded rocks appear natural. But you can pick the following rock types to create a minimalistic but modern look:

  • Square rocks.
  • Special-shaped rocks.

Further, rocks offer several options. For example, you can level uneven soil or add landscaping elements. Such elements can be pathways and patios. In short, there are no aesthetic limitations to these rocks.

Heat retention

When using rocks on top of potted plants, the soil will release heat indirectly to cold air. That’s because the temperatures must first go through the rock barrier. Then afterward, move through the mulching.

Again, rocks on top of soil help with the following:

  • Heat accumulation.
  • Protection against cold weather damage.

Moisture balance

Moisture efficiency is another benefit of putting rocks on top of potted plants. They create barriers that block moisture evaporation into the atmosphere.

Moreover, placing stones close to house plants and arranging them is common.

Elsewhere, the barriers help in water retention in plant roots.

Related: Best self-watering containers

Reducing erosion

Rocks prevent soil dispersion from wind since they’re heavy. They work wonders, especially on dry soil, since they’re prone to distribution from winds. Further, covering topsoil using rocks is an excellent way of reducing water impact.

The said moisture may come from watering or raindrops.

Animal protection

Discourage your lovely pets from interacting with the potting soil. Fortunately, putting rocks on top of potted plants helps deal with that issue. Otherwise, your pet may ruin your plants and the soil too.

Just place some stones on top of the soil. Doing so makes it challenging for them to reach the potting mix.

Fungus gnats protection

Among insects infesting indoor and outdoor plants, the Fungus Gnats stand out. That’s because they cause critical and heavy damage to plants. Moreover, they do so even though they’re tiny.

Further, these Fungus Gnats will lay eggs in your soil. So, if you put rocks or gravel onto the soil, you’ll prevent egg laying.

Putting rocks on top of potted plants prevents fungus gnats naturally. That’s if you stay within beach/urban areas with ready sand/rocks. Also, putting beneficial nematodes on top of potted plants kills fungus gnats.

Nematodes are microscopic worms. They destroy organisms like pupae/larvae by injecting an enzyme into their bodies.

Preventing weeds

Weeding around plants has always been a burden to some.

And in most cases, they prefer seeking help to weed them. Thankfully, putting rocks on potted plants is a sure way of preventing these weeds.

That’s so since stones will block sunlight within places where it isn’t necessary. Then again, that’s the best way to maintain plant pots and beds. All that without spending more time weeding.

What are the Problems of Putting Pebbles on Top of Potted Plants?

Destructive temperatures

Rocks with dark colors become hot or boil in the summer. That happens when intense sunlight hits the rocks. In short, the temperature increase within the rock spots becomes excessive.

So, if the stone layer heats too much or becomes dense, it’ll damage your potted plants. It would help to know the amount of sunlight that hits the spot.

If the sunlight amount is excess, use any rocks provided they aren’t dark.

Increased weight

Some tropical plants dislike stones that press against their root system. They do so since such pressures can badly affect their root health.

Moreover, heavy rocks compress the soil, erasing their small air pockets.

Further, you won’t have well-draining soil when these air pockets block. Furthermore, the ground may waterlog. 

To improve drainage, use lightweight rocks.

Toxic components

Often, when placing rocks on potting soil, some do that to add contrast and color to the plants. In doing so, they expose their plants to toxic chemicals. That’s because some rocks have colors with harmful chemicals.

When rain/sun hits these decorative rocks, the chemicals in them dissolve into the plants. Thus causing damage to the plant’s roots or other parts. Also, harmful chemicals may affect your container gardens.

To avoid that, use chemical-free or artificial rocks.

Best Rocks for Indoor Plants

1. Brick chips

Big brick chips work well when mulching or landscaping. That’s so since their color never flakes or fades off because of the red hue. Apart from that, these chips hold water and won’t deteriorate.

Moreover, these bricks’ density is 1500 pounds for each cubic yard. On the opposite, tiny brick chips work well on the following:

  • Potted plants.
  • Walkways.
  • Trails.
  • Planting beds.

Also, they’ve got a density of 1800 pounds for each cubic yard.

2. Crushed gravel

Gravels are fabulous mulches since they work well when covering the soil. That’s because they prevent soil surface evaporation and erosion. Moreover, wind can’t move them, unlike wood chips. It would help to use Medium-sized gravel since the tiny ones can fly away.

I recommend using crushed gravel around any tree or bed type. Elsewhere, you can get crushed gravel in several colors. For example, they’re available in standard colors like white, gray, brown, and black.

Read: What size planter do I need for a cactus?

3. White gravel

Apart from white gravel being beautiful, they’re functional too. Their white color reflects sunlight onto growing plants. So, when they do that, they boost light intensity. Also, their white color performs better than dark ones.

They do so since the chips heat less, meaning your plants will be comfortable. Apart from that, one can use them around trees and for beds.

4. Lava rock

Mulch from lava rocks works as a protective layer for your soil.

Further, they prevent soil loss by preventing soil erosion. Fortunately, they do so while allowing nutrients to flow through. Lava rocks also reduce water evaporation, preventing drastic water loss.

Lava rocks can have a brownish-gray or black color. But depending on their locations, they can be a mixed shade of colors.

5. River rocks

River rocks are ideal for landscaping since they fit and are multipurpose. Other than on the ground, you can use these rocks differently. For example, these rocks can be an outdoor fireplace or a walkway.

6. Marble

Marble chips are an excellent inorganic mulch option for potted plants and beds. Also, you can use these chips to add a different look to your paths or patios. But remember to observe the sunlight levels. That’s because sunlight in full-sun locations might be extreme for your plants.

Are There Alternatives to Use Instead of Using Indoor Plant Rocks?

Organic Mulch

Nothing can ever go south when using organic mulch. I say so because it’s a natural product that decomposes with time. And when it decomposes, it adds beneficial nutrients to your potted plants. It’s worth noting that any organic mulch available for purchase works.

Often, at local garden centers, chances are you’ll find simple wood chips. The chips may be from cypress, pine, or cedar trees.

Grass Clippings

You can use clippings from mowing the lawn to improve your potted plants’ health. Like organic mulch, grass clippings break down and improve soil quality which is why it’s allowed to leave them on your lawn after mowing. Moreover, their breakdown is faster since their ends are dead.

Mainly, grass clippings can be beneficial to your vegetables. But they work well on any plant. Only apply one to two inches of clippings for better results.

Pine Needles

Have you got any pine trees within your home? If so, I bet several pine needle tons are lying around your yard. The good thing is you can place them on your potted plants. They’ll protect your potting soil.

Best of all, their material won’t compact since it decomposes. Thus, your soil will remain well-draining and light.

Peat Moss

Sphagnum and peat moss are excellent alternatives to rocks. For example, peat moss conserves your soil’s moisture levels. And when in colder climates, it maintains favorable soil temperatures.

Coconut Fiber

This coconut fiber entails the stringy material coming from the husks. In gardening, the fiber material is popular. They come as mulch, rolls, or even containers. Beyond its standard benefits, the fiber won’t affect the soil pH balance.

They don’t do so since they have near-neutral pH levels even when decomposing.

Rubber Mulch

Often, rubber mulch comes from recycled car tires. Moreover, it’s a synthetic product or material that’s durable. The mulch also repels pets, making it a huge plus for outdoor pots.

What are the Best Plant Drainage Rocks?

The best rocks for drainage in pots are the following:

Smart Gravel Eco-Friendly Plant Drainage. These drainage rocks have an efficient moisture balance, keeping your soil moist. Moreover, they’re perfect for young plants and are straightforward to use. 

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Legigo Organic Clay Pebbles. Their porous structure provides efficient plant drainage and aeration. That ensures the plant’s root system has no saturation from over-watering. Apart from that, these pebbles improve oxygen circulation within the root system.

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Do Rocks Help with Drainage?

Rocks at the bottom of plant containers don’t help drainage and plant health. Instead, the plant roots may encounter saturated soil that won’t drain well. All that is because of perched water tables.

Ideally, when watering our plant pots or when the rain does it, water percolates. It does so through the soil towards a drainage hole below. All the plant roots will receive moisture, and if excess, it’ll drain away.

But in plant pots with rocks at the base, moisture will percolate via the soil. The moisture moves sideways when it encounters the different layers. When that happens, a saturated zone will form.

Further, water in that zone will hang on a unique layer.


Can I put stones around plants?

Putting stones around your plants within a tray is an excellent idea. They’ll increase your indoor plants’ humidity levels when need be. So, they work well for plants needing more moisture. Also, using pebble trays provides drainage space. That’s so since you’ll place the rocks directly below the planter pot. Moreover, that’s a perfect tip if you’ve got tropical plants. 

What should you put on top of potted plants?

The following are topdressing options for potted plants:

  • Hardwood mulch.
  • Moss.
  • Crushed glass.
  • Replica coverings.
  • River rock.
  • Crush slate.

It would help to get a gardening expert to pick the best top-dressing option for your potted plants. That’s because of the many options. For example, a Planterra horticulture expert will help you with that.

What are the white rocks in potting soil?

In summary, tiny white balls or rocks are known as perlites. The perlites are volcanic glasses or materials with ultra-low densities. Also, the perlites have temperatures above 870 degrees. In horticulture, perlites improve soil aeration and drainage.

They’re ideal for potting mixes. Moreover, perlites also help recover compacted soils where plants never grow.

Should you put rocks in the bottom of a planter? 

Not really. Rocks at the bottom of plant containers don’t help drainage and plant health. Instead, the plant roots may encounter saturated soil that won’t drain well. All that is because of perched water tables.

Ideally, when watering our plant pots or when the rain does it, water percolates. It does so through the soil towards a drainage hole below.

How to repot a plant with rocks

Here’s how to use rocks to repot your plants:

  • Pour a fresh potting soil layer into an empty planter pot.
  • Pack the soil layer to remove air pockets.
  • Layer the planter’s bottom using gravel or lava rocks. Do that if your planter lacks a drainage hole. Again, do so before adding your potting mix.

The primary goal is creating crevices to allow the pooling of the extra water away from your roots.

How to use rocks for drainage

You can lay a drain rock over pipes within a hole or trench. Doing so lets moisture move through them into your perforated pipes. Further, that’s an excellent way of protecting structures from moisture damage. That’s especially near foundation lines.

Often, gardeners use larger drain rocks for french drains. But for an entire driveway, it would help to use smaller gravel. 

Can you put gravel on top of soil? 

Laying pea gravel on topsoil can be a problem. At the same time, placing loose gravel on the topsoil will make it migrate. That’s especially if your potting soil will be open to vehicle or foot traffic. Moreover, it would help to grate the area and reapply the gravel to keep it even.

How to use clay pebbles for houseplants

Here’s a step-by-step guide on how to use clay pebbles for houseplants:

First, rinse the pebbles to remove any dust. Then, add a layer of pebbles to the bottom of your plant pot for drainage. Fill the pot with soil and plant your plant. Add more pebbles to the top for decoration or to keep the soil from drying out too quickly. Water your plant as needed.


Finally, it would help to consider different factors when putting rocks on top of potted plants. For example, sunlight availability and soil type are some of the factors. Also, check if your potted plants will or won’t handle the extra weight from the rocks.

If you aren’t sure, contact your favorite gardening expert. 

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