I’m trying to grow plants in pots and was curious to know whether a bigger pot is better. This post has my research on how the size of pots can affect plant growth.
Plants grow bigger in bigger pots because their roots will try to grow through the entire available soil. They do this to get as many nutrients from the soil as possible. Research shows doubling plant pot size makes the grow over 40 percent larger.
You need to select the best possible pot size for your plants to give them a great chance of growing healthy and strong. I’ve written a lot more details below on how you can choose the best pot size for your plants.
Will using a bigger pot help your plants grow bigger?
You know using a pot smaller than the plant’s size will cause problems. The roots of the plant will grow to cover the entire soil available in the pot and become root-bound.
The roots don’t get enough nutrients from the soil. There’s not enough moisture for the plants. And the plant can topple as it becomes top-heavy.
But how big a pot should you use? If you know the plant is going to grow large, should you choose a very big pot from the start? That would be a mistake.
It’s true that the roots will grow to the area available in the soil. And the bigger the pot, the more area available to the roots.
The problem is that if you plant a small plant in a very large pot, the soil can remain moist for a longer time. This is because there are not sufficient roots in the soil to absorb all that moisture.
Having moisture in the soil for too long means you have issues like root rot and fungal diseases.
Another problem with using too big a pot for your plants is the roots get a lot more nutrients than they need. This can cause your plants to burn due to excess nutrients.
A bigger pot provides the needed soil for growing the plant to its full capacity. But that does not mean the excess nutrients in the soil will make the plant grow faster. The rate at which the plant will grow remains the same.
How to know what size pot to use?
It’s important to select the right size pot for your plants. That’s why it depends on the type of plant you want to grow.
The general idea is to go for a pot that is one size bigger than the current size of the plant. You can measure the size of the plant by its diameter. And you can get pots that are from 2 to 24 inches in diameter.
So if a plant has a diameter of 4 inches, you need to pick a pot that is 6 inches in diameter. As your plant grows bigger, you’ll need to repot it into a bigger pot.
If the plant is small like a succulent and won’t grow much, there’s no need for a very big pot. You can grow it in a pot that is one size bigger and that should work.
The same holds true for most potted plants that usually grow 6 to 8 inches thick. You can choose a pot that is 8 to 10 inches in diameter and that should be fine.
It’s important that the pot should be deep and not just wide. Deep pots are beneficial for the plants to spread their roots below due to the effect of gravity.
How to measure the size of pots for plants?
The size of the pots is measured in inches. You can use the dimensions of width and height to figure out whether the pot is suitable for your plants.
If you’re planting indoors, a narrow but deep pot should be sufficient. But if you’re planting outdoors, you may need a wide and deep pot. This helps protect the plants from toppling over due to windy conditions.
Some pots have a wider rim and a narrower base. You need to consider the width of the pot at the base to see if it’s suitable for your plants.
How do you know when a plant needs a bigger pot?
You should always be proactive to repot your plants into a bigger pot when needed. This helps keep your plants healthy and protect them from diseases.
But there are certain symptoms your plants will show you when they feel cramped up in their pots.
If the roots are growing out of the drainage holes, it’s time to repot the plant in a bigger pot.
When the soil is covered with roots, there’s no place to retain moisture. So when you water the plant, most of the water will run out quickly.
If the soil dries out fast and you need to water the plant often, it’s a sign that the plant has outgrown the pot.
You can lift the root bulb out of the pot to check it periodically. If the root ball is a mess of tangled roots and there’s not much soil, it’s a sign that the plant is root-bound. You need to move it to a bigger pot.
A plant that outgrows its containers becomes top-heavy. You may see the plant topple over often even when there’s no wind to cause it.
A plant that has outgrown its pot does not get sufficient nutrients from the soil. This makes the plant’s growth stunted. You may see slow growth as well as a lack of foliage and flowers on the plant.
How to repot your plant?
Once you know the plant has outgrown the pot, it’s time to repot it into a new pot.
- You need to prepare the new pot by sterilizing it. You can do this by soaking it in a mix of 1 part bleach with 9 parts water for 30 minutes. Then wash it with water.
- Water the plant well before taking it out of the old pot. This will make it a bit easier for the roots when you move it to another pot.
- Take the plant out of the old pot. You can do this by tilting the pot and gently tapping it to get the root ball out.
- If that does not work, you can use a knife to gently bring the roots out of the pot. If the plant is root-bound and difficult to remove, you may need to cut open the pot.
- Check the roots of the plant to see if any damage is present. Cut off roots that are damaged, have rotted, or tangled up.
- Place the plant into the new container and cover up the roots with soil. Cover all the roots up to the level as the original pot.
- Now water the plant well so that the roots and soil can settle with plenty of moisture.
- You should keep the plants away from direct sunlight and the elements for a few days to avoid transplant shock.
How to restrict plant growth?
You now know that the plant can grow only as much as the pot size will allow. That’s because the roots are limited in the nutrients they can gather from the soil.
You can use this technique for your benefit as well. If you have limited growing space, maybe you don’t want the plants to grow as big. When you plant them in small pots, they will grow only to fill them up.
You do need to take care that the plant does not get root-bound. This will prevent the roots from getting sufficient nutrients and kill the plant. You can often check the roots of the plant and prune them to avoid this problem.