The type of pot you choose can increase your chances of successfully growing your new houseplant!
This post will discuss my best tips on how to choose the best pot for your plant’s health.
Table of Contents
- Pick a Pot with Drainage Holes
- Pick a Pot with the Material that Suits You and Your Plant’s Needs
- Pick a Pot the Right Size for Your Plant
- But What if You Want to Pick a Pot Without Drainage Holes?
- It is possible to use a pot without drainage holes as a cover pot (or cachepot).
- There is a way to successfully setup a pot with rocks in the bottom and have it drain excess water. Here’s how.
- The Perched Water Table and What it Means for Your Plant’s Pots
- Big Takeaways
- Related Posts
Pick a Pot with Drainage Holes
Drainage holes allow excess water to have a place to exit the potting mix so the roots of your plant don’t accidentally drown.
If your plant is stuck in a pot that is retaining too much water, the amount of air in the potting mix is severely reduced. Because roots need air, water, and nutrients to maintain health, the roots begin to drown and rot.
Be aware that smaller drainage holes will make it more difficult to ensure a pot is properly drained.
For example, I have found that decorative pots with attached saucers look nice, but are more difficult to remove excess water because these pots often have only one small drainage hole on one side of the pot.
Because of this, I try to purchase pots with removable saucers and ample-sized drainage holes. Then I can easily take the saucer where excess water has collected and dump it out.
Bigger drainage holes or a larger number of drainage holes provide more opportunity for water to drain and less of a chance for the potting mix to stay wet for too long of a time.
Pick a Pot with the Material that Suits You and Your Plant’s Needs
The material the pot is made out of will affect how long the water will be retained in the pot. Plastic pots, for example, retain moisture for a very long time compared to a terra cotta pot, which is made of a porous material that wicks moisture out of the soil.
This is a very important consideration when determining what type of pot to choose for your plant. The vast majority of plants do not want to be wet for long periods of time. It can be advantageous to choose a type of pot that does not retain moisture for a lengthy amount of time.
General notes on pot types:
- Terracotta pots – inexpensive, helps to wick moisture from soil, great drainage
- Ceramic pots – ranges in price, retains moisture much longer, may or may not have drainage holes
- Cement / Concrete pots – more expensive, heavier planters, does wick some moisture, may or may not have drainage holes
- Plastic pots – often very inexpensive, retains a lot of moisture, may or may not have drainage holes, often is very light which can be problematic for top-heavy plants
I personally house 95% of my houseplants in terra cotta pots. They are inexpensive, great for preventing overwatering, easy to replace if needed, and easy to match (for those who like to have pots that match).
Pick a Pot the Right Size for Your Plant
Typically the pot that you choose should be the same size or only an inch or two larger than the pot your plant came home in.
If the plant looks dwarfed by its pot, then the pot is probably much too large. If the plant’s roots are winding around the inside of the pot and there is very little soil left, then the pot is probably too small and an upgrade to an inch or two larger in diameter is in order.
Potting a plant in too large of a pot results in the plant having a very large and overwhelming body of soil. When that entire body of soil is watered, the plant is not large enough yet to be able to efficiently use that amount of water in a reasonable amount of time. As a result, the plant may develop root rot from sitting in wet soil for too long.
But What if You Want to Pick a Pot Without Drainage Holes?
It is possible to use a pot without drainage holes as a cover pot (or cachepot).
In other words, the cover pot is only a decorative pot whose sole purpose is to look good. The plant will actually be living in a thin plastic pot or a nursery pot that you can slip inside the cachepot. Often people use the pot the plant was in at the time they purchased it.
Doing this allows you to remove the plant from the decorative pot, water it thoroughly, and then return the plant to its decorative/cover pot.
Some places will tell you that it is possible to plant in a pot without a drainage hole if you put gravel in the bottom. The scientific research behind this method has proven that this is more likely to cause root rot. If you would like to understand why, keep reading about the Perched Water table below.
There is a way to successfully setup a pot with rocks in the bottom and have it drain excess water. Here’s how.
Essentially, you add a strip of sponge going from the potting mix down into the rocks. This sponge will act as a drainage hole (sort of) and allow the excess water in the potting mix layer to drain into the rock layer.
To learn more about the science and the setup, watch the video below where a soil scientist explains why this method is successful and how to easily set it up:
The Perched Water Table and What it Means for Your Plant’s Pots
To understand why using gravel in the bottom of a pot isn’t often successful, we have to understand the perched water table and how that relates to our potted plants:
When we water a plant, the water is not evenly distributed throughout the soil as we might prefer or expect. Instead, gravity pulls the water down, and the majority of the water collects lower in the body of the soil.
Putting Rocks in the Bottom of Pots
To try to remove excess water without drainage holes, some people thought that adding rocks or another coarse material in the bottom would allow the water to pass through the soil layer and drain into the rock layer.
But Your Soil is Basically a Sponge that Doesn’t Want to Let Go of the Water
The Perched Water Table shows that adding rocks doesn’t actually change the moisture level in the soil because potting mix has a saturation point regardless of the rocks it is sitting on.
In other words, the potting mix will retain a certain amount of water (as it is basically a sponge soaking up water) regardless of whether we add a layer of rocks below it.
However, you could also do a similar experiment where you use several different types of potting mix with various ingredients and see what the perched water table looks like in each scenario. All you need to do is water the pot thoroughly and then let it drain and sit for a few minutes.
Pot Size Doesn’t Matter!
To take this matter one step further, this saturation level is the same regardless of the size of the pot. So if the saturation level of potting soil is 2 inches, then half of a 4-inch pot will be saturated.
If you fill 1 inch of your 4-inch pot with rocks and 3 inches with soil, how much soil will the plant’s roots have? (Usable soil is defined here as soil that isn’t super wet and suffocating.) The plant would only have 1 inch of usable soil. Why? 2 inches of soil would be saturated and 1 inch would be the rocks at the bottom.
If your plant is in a 2-inch pot and your potting mix has a saturation level of 2 inches, then the entire pot will be saturated.
Big Takeaways
- Buy pots with drainage holes to help prevent over-watering
- The material the pot is made out of effects the amount of time the soil retains moisture
- You can use pots without drainage holes. The best way is by using them as cover pots.
- Adding rocks alone in the bottom of pots without drainage doesn’t help; in fact, it does just the opposite!
- If you do want to use rocks as a drainage layer, add a strip of sponge traveling from the potting mix into the rocks to change the pressure in the pot and drain the excess water.
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