When I started container gardening, one of the questions was what material pot should be used. Cement pots were one of the choices and I wanted to know more.
Cement pots or concrete planters are good for plants because they are strong, porous, and provide good insulation. They are especially useful for outdoor plants making them hard to steal. They are heavy and won’t topple over in the wind outside.
This post will help you understand the benefits and drawbacks of using cement pots for plants. And I will also show you how to prepare your cement plants before use not to harm your plants.
Benefits of using cement pots for plants
Cement pots are durable
One of the biggest benefits of cement pots is that they are very durable compared to other materials like terracotta or ceramic.
Once you start growing a plant in a cement pot, it can last you several years. You could damage the pot if you drop it or leave it outside when the weather is freezing.
I’ll discuss about sealing the cement pot later but that method can ensure it becomes even more durable.
Cement pots are porous
If you get a cement pot that is unsealed, it will have a porous texture similar to terracotta. This means the moisture will seep out of the pores.
There is less risk that you will overwater the plants in such cement pots because of this porous nature. This will mean that you need to water the plants a little bit more often than if you had a sealed pot without the pores.
Cement pots provide insulation to the soil
The texture of cement helps to keep the heat trapped inside the material. So if you use a cement pot, the soil inside the pot will stay a little warmer than soil in a regular pot.
This makes cement pot a good choice for growing warm-season plants that need high temperatures to grow well. You will be able to extend the growing season a bit even if the outside temperature gets a bit cooler.
Cement pots are heavy and won’t fall
Cement pots can get quite heavy especially after you added water and potting soil to it. The benefit of being heavy is the pot won’t fall over during windy conditions.
It’s difficult to move a heavy pot so there are fewer chances someone may steal your plants when you leave them outside.
Drawbacks of using cement pots for plants
Cement releases lime into the soil
The biggest problem with using a cement pot is that it may contain lime. This lime will leach into the soil when you water the plants.
The lime is not toxic but it will change the soil’s pH level making it more alkaline. This can make the soil less suitable for some plants.
If you try to grow plants that prefer neutral or acidic pH in the soil, it will stunt their growth and even kill them.
Cement causes efflorescence that can harm plants
The cement can leach out salts into the soil when you water the plants. This salt comes from the cement itself as the air brings it out from the pores in the material.
The roots cannot determine that the plant needs more water due to the excess salt buildup over time. This will cause dehydration as the plant does not take in as much water as required.
Cement is porous that can cause underwatering
One of the benefits of cement pots can also be a drawback. Since the material is porous it tends to release water from the pores.
This means that unsealed cement pots need to be watered more often than some other materials like plastic. You need to be careful with the watering or risk underwatering the plants.
The other problem with being porous is that cement will absorb moisture from the environment. This can cause fungus or moss to grow on the outside of the pot.
Cement pots can get quite heavy
Cement pots can become very heavy especially after you have added soil and water to them. You need to ensure you keep it at the right location so you don’t have to move it later.
If you have to move the pot due to a change in weather or just for a landscape change, it’s better to place it on a wheeled base to make moving it easier.
Large cement pots can be expensive
You can get cement pots of different sizes for growing all kinds of plants. But the bigger the pot, the more expensive it will get.
Cement pots tend to be more expensive than pots made from materials like terracotta or plastic.
Are concrete planters safe for vegetables?
Concrete planters are safe for vegetables as long as you get the lime out of them before growing the plants. You can also seal the concrete planter with a concrete sealer so the lime cannot leach into the soil.
Are concrete pots good for succulents?
Concrete pots are good for succulents because they leach lime into the soil. The lime increases the pH level of the soil making it more alkaline. Succulents plants prefer to grow in soil that is alkaline which makes concrete pots suitable for them.
Do concrete planters need to be sealed?
Concrete planters need to be sealed only if you want to use this as a method to prevent lime from leaching into the soil. You can also seal the concrete planters to increase the durability of the planter by blocking the pores.
Prevent lime from leaching into the soil
Concrete planters may contain lime that would be leached into the soil when watering the plants. This could be a problem if you try to grow plants that prefer neutral or acidic soils.
If you want to prevent the lime from leaching into the soil, one method is to seal the concrete planter. The seal will cover the surface of the concrete and prevent the lime from leaching out.
Improve the durability of the concrete planter
If you seal the concrete planter, it also helps make the planter more durable as it will not chip or crack easily.
The pores of the concrete planter can accumulate water that can freeze in cold weather. This can expand and contract the pores causing the concrete planter to weaken over time. When you seal the concrete planter, the pores are covered up and you won’t face this problem.
Improve the looks of the concrete planter
If you want to improve the aesthetic value of your concrete planter, you can seal it so the concrete material won’t look as plain.
A sealer will protect the surface from dirt and stains and keeps the concrete planter looking new for longer.
How can you seal a concrete planter
You should clean the concrete planter before you attempt to seal it. You can also remove most of the lime as part of the process.
Spray water 2-3 times every day and do this for a week. Please make sure the planter has dried before you spray it with water again. Most of the lime will leach out with the water.
Get a good concrete sealer and paintbrush you can use to seal the concrete planter. Place the planter upside down on a tarp and apply the 1st coat of the sealer to the outside of the planter. Leave it to dry overnight.
Now you can apply the 2nd coat of the sealer to the outside of the planter and leave it to dry for the next day.
Straighten the concrete planter and apply the 1st coat of the sealer on the inside of the planter. Allow it to dry overnight.
Now apply the 2nd coat of the sealer on the inside of the planter and let it dry overnight.