At a minimum, your potted plants need air, light, and water to survive. But to thrive, your plants will need healthy roots. If your potting container has poor drainage, your plant might suffer from root rot and die. We have created this post to help you learn how to improve the drainage in your potted plants.
There are three main ways for you to improve the drainage in your potted plants:
1. Use the correct soil-free that is designed to drain 2. Choose a deep planter or container 3. Do not add stone, pebble or shards of clay
Those three steps sound easy and are an excellent starting point for you. But not all of us have a natural green thumb. Keep reading as we guide you through the details of how you can grow healthier plants by promoting proper drainage.
Choosing The Right Soil For Your Containers
According to Texas A&M AgriLife Extension, the density of garden soil or dirt as it’s better known prevents proper drainage. You shouldn’t use 100% dirt or soil from a store or your yard in your plant container.
That might sound like we are crazy, so let us explain. Soil and dirt are fine for trees, plants even your in-ground garden. Roots have plenty of space to grow in the ground. And ground soil can be aerated so when you saturate an in-ground garden, and it will drain.
Containers have limited space, and traditional dirt will soak up the water like a sponge, but it won’t drain. The lack of drainage can waterlog your plant. What you need to use is a “potting mix.” A potting mix doesn’t contain soil or dirt. Instead, this mix is created from materials like peat moss, perlite, and vermiculite. These materials are lightweight and allow air to flow as well as water to drain.
You’ll find these mixes at your local nursery or home garden store. There are soil-free soils explicitly created for different types of plants. You’ll be able to find a perfect match for your plant of choice.
Deep Planters Let Your Roots Breath
Choosing a taller or deeper container for your plants allows gravity to do it’s work when it comes to wicking away water. More soil mix means more air and water that is aerated for your plant’s roots even if the base layer is saturated. A shorter planter with less soil mix might hold on to too much water.
If the soil in your plant container doesn’t drain, the roots can become stressed. According to the University of Georgia Extension, too much water can lead to root rot. Plants need water, but they also need air to survive. With a lack of air, your plants will feel smothered.
Overwatering is a cause of root rot, but the excess water is likely because your soil can’t release the moisture. When your plant’s roots can’t breathe or get the food they need from soil because they are too wet, the result is an unhealthy plant. To prevent an early demise of your plants, you need to pick the right soil.
What Can I Add To Soil To Improve Drainage?
As we have discussed, traditional soil is not ideal for adequate drainage. It holds onto water and makes it difficult for you to aerate the soil in a small container.
If you are unable to find a soil-free mix, you should consider adding other materials to the soil to make it lighter. Let’s take a closer look at peat moss, perlite, and vermiculite as these are your best options for getting a soil that won’t get soggy or mucky.
- Peat moss is a fibrous material that can hold a lot of water and release it to your plants as needed. It's super light but does the job wicking away the water.
- Perlite is a material composed of volcanic glass that is heated to expand many times its original size. The result is a lightweight product that porous, absorbing the water in your plant container
- Vermiculite is a pellet-shaped material composed of minerals. Like perlite, vermiculite is lightweight and will soak up water. It’s ideal for your container plants because it lets air flow through the soil.
Adding a bit of each of these materials to your dirt will help you create a soil that will be lighter and less likely to rot.
What Can I Put In The Bottom Of A Planter For Drainage?
You might think that a layer of rocks at the bottom of your plant container is the perfect choice for improving drainage. But we did the research, and it’s learned it’s not a good choice at all.
The main reason that rocks or any similar material don’t improve your drainage is that they don’t soak up the water. Rocks sit in the container and wait to take on what water your soil releases. And, that’s assuming the soil drains.
In this post, we’ve covered some materials that you can add to the soil to improve the release of water. A couple of other ideas for you to consider are adding wood chips or pine bark nuggets to the bottom of your container.
For best drainage results, we recommend that you focus on getting the right soil-less dirt for your plant container. Visit your local nursery or garden store, and find the right mix for your plants.
Will Adding Sand To Soil Improve Drainage?
Sand will improve soil drainage. It’s not the best choice, but it’s inexpensive.
If you decide to add sand to your potting soil, choose coarse sand as the texture will lend itself to better drainage. Fine sand doesn't have enough texture to break up the dirt. Keep in mind that while sand is cheap, it’s also heavy to haul around.
What Can I Use To Fill The Bottom Of A Large Planter?
Filling space at the bottom of a large container is an easy problem to solve as long as you aren’t expecting help with drainage. We know that the potting mix can get expensive when trying to fill a large container. Here are a few inexpensive ideas of materials that take up space:
Rocks or shards of pottery
Rocks, gravel, and shards of broken pots or bricks are a great base layer for your big planter. The materials will not easily break down and are bulky enough to take up space. A bonus of these materials is that they are heavy and can holder your planters in place when the weather rolls in.
Styrofoam and packing peanuts are a common buffer in your shipped packages. These materials can be put to work in your planters. Pack them in plastic bags and fill the bottom of your planter.
Check your recycling bin for soda cans, water bottles, and even the bags your potting mix came in. All these items can add fill up space in a planter. It’s best to slightly crush the cans and bottles so that you can get an even surface to cover with your potting mix.
Remember, these items won’t help suck up excess water in your planters, but they are cheap solutions to fill in the void.
Should Planters Always Have Drainage Holes?
Yes, your planters should always have drainage holes. As we've discussed, adequate drainage is crucial for your plants to thrive.
If your container doesn’t have a drainage hole, determine if you can drill or punch in holes into the bottom of the planter. If it’s not possible, then you will need to use two pots or containers and create a draining system.
When using containers to create a drainage system, you’ll need two different sizes so that one of the planters can sit inside the other. Place your plant in a smaller container that has drainage holes or add the holes. Then, take the smaller pot and place it in the larger container that doesn’t drain.
You might want to consider emptying the water from the larger container once in a while.
How To Cover Drainage Holes In Pots
Sometimes your soil mix and pot will drain too well. When this happens, you might notice that the water is draining too fast, and you are losing that precious mix as well. Or you might have a dirty mess on your hands after watering your plants.
We have a few solutions for you to cover the holes but keep the water draining.
Cover the Drainage Holes
Before you plant, cover the holes from the inside with a piece of screen or mesh, a coffee filter, or folded cheesecloth. These items serve as a filter but still release water.
Use a Saucer
Find a saucer that fits under your planter. The saucer will cover the holes and will also collect any water that drains through the soil mix. Remember to empty the saucer, and you don’t want your plant sitting too long in extra moisture.
Use Water-Absorbing Materials
Peat moss and coconut fiber discs can also be placed over your drainage holes before you plant. These materials absorb and release water but won’t block drainage.
Let It Flow
Your potting containers need excellent drainage for your plants to thrive. If the plant’s roots get waterlogged, they can suffocate and kill your plant. Our best advice to make sure that you use a porous potting mix that is soil-free in your containers. Remember, regular soil and dirt are too dense for proper drainage.
We hope this post helps you and your potted plants flourish.