7 Alternatives to Using Rocks in a Planter

Some people add rocks to their planters to help with aeration and drainage. However, only some plants will like rocky soil. You’ll want to consider alternatives to keep your plants healthy and happy.

The best alternative to using rocks in a planter would be perlite. It offers improved drainage and doesn’t take up growing space like rocks do. Other options include moss, sand, and even newspaper. All of these items can offer different benefits to your potted plants.

This article will cover those alternatives in detail. After reading, you’ll better know which to pick for your potted plants. Let’s begin!

1. Perlite

First, let’s start with perlite. It’s one of the best materials you can add to your potting soil for several reasons. Perlite is a mineral that occurs in the earth naturally and looks like small white flakes. It has plenty of functions and can greatly benefit your plants.

Perlite is absorbent, so it can pull some excess moisture out of the soil. If you accidentally overwater your plants, perlite can help to dry out the dirt faster, preventing root rot. Adding perlite to the ground can create tiny air gaps that benefit aeration.

These air gaps are also suitable for drainage and are much better than using rocks. It’s also healthier for the plant’s roots since it won’t block them from spreading out. It’s worth noting that you use perlite by mixing it through the soil evenly and don’t simply leave it at the bottom of the planter.

Adding perlite to your potted plants is excellent for helping them grow. The material is perfect for adding more drainage and aeration and keeps your plants healthy. However, it doesn’t add any nutrient content to the soil. It’s only for changing the quality of your potting soil.

2. Sphagnum Moss

Next, you might consider using sphagnum moss. Many gardeners use sphagnum moss as a growing medium. However, you can also place a layer at the bottom of your planter and get great results. It’s thick enough to stop the soil from falling out of the drainage hole.

Plus, this moss is very absorbent. This natural material holds water like a sponge and will suck moisture away from the plant’s roots, which helps manage drainage. It works well for plants that like humidity since it slowly releases moisture into the air.

Sphagnum moss is also extremely fibrous, which helps to keep some air pockets in the soil and allows for ample drainage. It can help the soil retain its structure too. That way, the dirt can’t compress and make it impossible for the plant’s roots to keep growing.

However, this moss will make the soil more acidic, so not every plant will love it. If your plant prefers an alkaline pH, you may need to avoid using this alternative.

3. Newspaper

Many gardeners use rocks on top of their soil to stop water from evaporating from it so quickly. You might be surprised to learn that newspapers can do the same thing. 

Start by cutting the newspaper into a shape that fits your planter. Then, set it inside. At least three layers of newspaper are required to prevent moisture from evaporating from the pot.

It’s also suitable for trapping water inside porous pots, like clay. To do this, you’ll want to line the inside of the planter with newspaper before filling it with soil and adding your plant. The newspaper will help keep more moisture inside. Plus, it’ll eventually break down and combine with the earth.

So, if you live in a dry place, you can use newspaper instead of rocks in your planter. It can’t offer better drainage, but it will help trap moisture in the planter longer. If your plants always seem thirsty and their soil’s always dry, it’s a great option to try.

4. Coffee Filters

Coffee filters are a good alternative when you have a large drainage hole on your planter and need to stop dirt from flowing out each time you water your plants. It’s better than using rocks at the bottom of the planter because they won’t block the drainage hole. 

Water can easily pass through the planter, but your soil won’t escape. It’s much more efficient than using rocks. Plus, you can easily combine this method with others on this list and get excellent results.

Coffee filters are perfect for cleaning your space without lowering drainage in your potted plants. However, they can’t offer you as many benefits as rocks, or other materials, can.

5. Packing Peanuts

Packing peanuts are a fantastic alternative to using rocks at the bottom of your planters. You’re also repurposing them, which can keep them out of landfills longer. Before using packing peanuts, you’ll want to dip one in water and see if it dissolves. If it does, you can’t use it in your potted plants.

The peanuts can support the root system and are perfect if you want to set another planter inside a larger one. They can easily hold the weight of the soil and the plant without compressing for a long time.

You’d use them the same way you’d use stones in the bottom of a potted plant. They can provide some aeration and space for water to drain. Although, you’ll need to be careful not to use too many of them, so they don’t invade your plant’s growing space.

Is It Safe To Put Styrofoam in a Planter?

It’s safe to put styrofoam in the bottom of a planter. It won’t break down, so you won’t need to deal with soil collapsing and compressing. Packing peanuts are made from styrofoam, so they’re safe to use.

You should refrain from adding packing peanuts that dissolve in water because they’ll break down the first time you water plants, causing the dirt to shift.

The only downside to using styrofoam is that it doesn’t offer your plants any nutrients. It simply takes up space at the bottom of the planter, which is fine when you only need a drainage layer.

6. Wood Mulch

Wood mulch is good for potted plants too. As the mulch breaks down, it returns nutrients to the soil that your plants can use to grow. You can set mulch on top of the dirt’s surface to trap moisture, but you don’t want to place it too close to the base of your plants. Many gardeners find that mulch looks nice too.

You can also put the wood mulch at the bottom before adding the soil and your plant to the pot. Doing so creates a layer that can help enhance drainage. The mulch will continue putting more nutrients into the soil, so they’re usually better for your plants than rocks.

Although, it’s not good to mix the mulch with soil. You either want to leave it on the top or bottom, not combine them with each other. Mulch mixed with soil can cause issues with the nutrients in the soil.

7. Sand

Not all plants like sand very much, so you’ll want to be careful when adding it to your pots. Adding a bottom layer of sand can help keep the plant’s roots dry and lower the odds of it getting root rot. 

You can also mix sand with the soil for some plants. It adds more air pockets and weight to the planter, so it doesn’t fall over as easily. You’ll want to choose coarse sand since the fine grains won’t help much with aeration.

(PAA) Should I Put Something in the Bottom of My Planter?

You should put something in your planter if it’s large or needs more drainage. It helps to fill the pot, and you don’t have to use as much soil. However, you don’t always need to. Your plants must have enough room to spread out their roots as deep as they need to.

You’ll want to put something in the planter if it’s big and you plan on setting a smaller planter inside of it. You can still use your sizeable decorative pot, but the plant can still get the necessary drainage. 

Rocks, packing peanuts, and sand can create a sturdy surface for your smaller planter to sit on.

As long as your planter has ample drainage, you might not need to add any other materials to the bottom of the pot.

Why You Should Choose an Alternative to Rocks

Rocks are only beneficial to potted plants in certain situations. They cause some issues with drainage, so you may not want to use them in all of your plants. Plenty of alternatives can offer you many of the same benefits for your plants without messing up the drainage in your pots.

For instance, perlite can do everything that rocks can, but it enhances drainage greatly. It’s generally a better choice because it works more consistently than adding stones or gravel to the bottom of a planter.

If rocks work for your plants, they’re perfect to use. However, you have plenty of alternatives in case they don’t!

Alexander Picot

Alexander Picot is the principal creator of TheGrowingLeaf.com, 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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