Do Rocks Help With Drainage in Potted Plants?

You might’ve heard of plant lovers adding rocks to the bottom of their potted plants. However, many people can’t agree on whether or not it helps plants. So, does using gravel increase drainage or not?

Rocks can help drainage in potted plants in containers lacking drainage holes. However, adding it to a pot that already has good drainage won’t do anything and could clog the drainage holes. You’ll need to inspect the pot before deciding whether it could benefit from gravel.

So, rocks can help with drainage, but only in certain situations. This article covers when and how you can use stones to add more drainage to your planters. Let’s get started!

When Do Rocks Help With Drainage?

Adding rocks to the bottom of potted plants doesn’t always help with adding more drainage. The stones can block the drainage holes, causing water to remain at the bottom of the planter. If the water can’t drain, it can easily lead to root rot

However, rocks can help add drainage if there are no holes at the bottom of the planter. The stones keep the soil above the water, so the roots don’t start to rot. Still, you must add the rocks correctly, or the plant will suffer. You don’t want to use too many stones, so a thin bottom layer is usually fine.

Mixing the stones in with the soil is the best option. So, instead of leaving a solid rock layer at the bottom of the planter, you stir the gravel in the soil until it’s spread out evenly. This process creates air pockets in the earth that can help increase drainage.

In short, rocks can help add drainage when used correctly. It’s best to mix them evenly in your potting medium. You’ll need to make sure no stones end up covering the drainage hole at the bottom as well.

If you’re having issues with drainage in your current pots, you might want to switch to fabric grow bags. These fabric pots have many benefits, including enhanced aeration and drainage, which can help plants with root rot recover.

Problems With Adding a Bottom Rock Layer

Adding a layer of gravel to the bottom of the planter isn’t always a great idea since it can cause two major problems with many plants. 

First, having a rock layer takes away from the amount of soil in the pot. That means your plant’s roots have less space to spread out and grow. Some plants require a certain amount of growing medium to thrive, so you don’t want to cut into that space with rocks.

Second, if the rocks block the drainage hole, the water will remain in the soil for a long time. Since there’s less growing medium in the pot, it’s easier for the moisture to reach the roots. It makes it easier to overwater your plants, causing root rot.

You can combat the second issue by giving the plant less water. This option works well when you want the excess water to sit in the rock layer, away from the roots. However, it can be difficult to tell precisely how much water the pot can hold without leaving the soil soaked.

How To Add Rocks to a Potted Plant

Adding rocks to the bottom of a potted plant can do more harm than good. However, that doesn’t mean you must skip out on using stones. The best way to use gravel for drainage is to mix the rocks evenly throughout the soil.

The rocks create air gaps in the soil, significantly increasing aeration and drainage in a pot. The water can pass through this gap quickly and reach the bottom of the planter, where it drains out. If your planter has no drainage holes, you should add them first.

If the pot doesn’t come with drainage holes, you can place a layer of gravel at the bottom, then add the soil. The water should drain into the rock section, where the roots won’t go. However, this setup isn’t ideal. Depending on the soil and how much water you use, it wouldn’t take long for the rock section to overflow, leaving the soil drenched.

Instead, you can place gravel in the bottom of a large pot with no drainage holes. Then, set up a smaller pot that has ample drainage on top of it. Doing so makes it easier to fit smaller pots into large decorative ones. It also allows the plant to get the drainage it requires, but you can still use your other pots that don’t have holes.

Overall, you don’t need to use gravel in potted plants that already have good drainage. You should save them for the ones that lack drainage instead.

Should You Put Rocks on Top of Potted Plants?

You shouldn’t put rocks on top of most potted plants since it’s not required for plants to be healthy. It’s suitable for plants that like warm soil since it helps trap heat. It also traps moisture in the soil longer.

You don’t need to put rocks over all of your potted plants, but it’s a good idea for plants like succulents and cacti. These plants thrive in warmer conditions, so the stones can help trap warmth in their pots.

You’ll want to research your potted plants before setting rocks on top of them. Some plants prefer warm conditions, while others want to be cold.

Do Potted Plants Need Rocks for Drainage?

You don’t need to add rocks to potted plants for them to thrive. In most cases, having a few drainage holes is good enough. Plus, many materials that planters come in are porous and allow the water to evaporate. Clay pots have many pores and allow for a lot of evaporation to take place.

Since these pots already have enough drainage, adding more rocks to the soil won’t do much for your plant. Unless it doesn’t already have holes for draining.

Perlite Is Better Than Rocks for Drainage

Perlites are the small white dots you see combined with potting soil. It prevents the dirt from compacting, adds air pockets, and makes water drain easier. If you want more drainage for your potted plants, perlite should be your go-to choice instead of rocks.

It’s much more reliable when it comes to drainage. Perlite can absorb more water than soil, helping to keep the roots dry. Rocks won’t absorb the water and can make it easier to overwater a potted plant, even if they keep the roots out of the moisture.

If you need more perlite to add to your potted plants, I recommend the Organic Perlite by Perfect Plants from You receive a large bag at a great price. The pellets are excellent for plant roots since they keep them dry and don’t get in their way, as a rock would.

So, if you’re looking to mix something with your potting soil to increase aeration, your best bet would be perlite. You can already find it in store-bought potting soils, but adding more wouldn’t hurt your plants. You’ll also need to use it to make your own soil from DIY compost.

Why Do They Sell Plant Pots Without Drainage Holes?

Stores sell plant pots without drainage holes because staff can overwater the plants, leaving a mess on the floor. It’s easier for stores to ban pots with holes instead of cleaning this mess every time it happens. Some planters are also meant to be purely decorative, so they don’t have a hole.

If you find a pot without a drainage hole, there are a few ways that you can still use it to grow healthy plants. The best option is to add a few gaps yourself using a drill. However, you can use stones if you don’t have a drill. Combining stones evenly in the soil should help with adding some drainage.

Although your plants will appreciate being in a pot with much more drainage, removing them from the planters they come in from a store is best. You can replant them in a container with improved drainage and then add that pot to the larger decorative one.

Overall, it’s more convenient for some stores to ban pots with drainage holes. It’s common for staff to overwater plants, which can be messy. You’ll need to repot any plants you get that come in a pot without drainage.

Final Thoughts

To summarize, rocks can add more drainage to potted plants, but only under specific conditions. You don’t need to use gravel in pots with large drainage holes. However, you can use them in containers with poor drainage or aeration. Most pots won’t need rocks but can benefit from perlite.

So, there are some ways that rocks can help with adding drainage. While a gravel layer can keep roots out of the water, it can also trap a lot of moisture, so you’ll need to be careful when using stones.

Alexander Picot

Alexander Picot is the principal creator of, a website dedicated to gardening tips. Inspired by his mother’s love of gardening, Alex has a passion for taking care of plants and turning backyards into feel-good places and loves to share his experience with the rest of the world.

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