It can be confusing.
You are planning to grow vegetables in containers but are not sure about the size to use.
Should you just pick a random size? Or get the largest container possible?
In this post, I’ll give you a general guideline to pick a container in just a few seconds. I’ll also give you a detailed table that specifies the container size you can use for each vegetable.
How to choose the right container size for vegetables
Check the vegetable seed packet to find the size of the plant at maturity. Then you can choose the container size based on the mature plant size using the general guideline below.
You need 8-10 gallons container that has 12-16 inches depth for large vegetables such as peppers, tomatoes, eggplants, and cucumbers. If the plant is bigger and needs more depth, you will need a 15-20 gallon container.
You need 4-6 gallons container that has 8-12 inches depth for medium-sized vegetables such as beans, beets, chard, carrots, cabbage, lavender, parsley, and rosemary.
You need 1-3 gallons container that has 4-6 inches depth for small vegetables such as garlic, cilantro, thyme, basil, radish, spinach, and peas.
|Plant||Plant Spacing (inches)||Container Depth (inches)||Container Size (gallons)|
How deep does the container need to be?
You need the container to be deep enough that the roots can grow comfortably. If you follow the guideline or table I provided, you will be fine.
If the container is smaller than required, the roots won’t get growing space and encircle the container. We call this being root-bound where roots develop into a mangled mass inside the container.
This is a problem because the roots don’t get the required nutrients and moisture from the potting soil. This affects the health of the plant and you won’t get a good vegetable harvest.
For example, for a tomato plant that grows large, you’ll need a container that is 12 inches deep. If you’re growing a root vegetable such as carrot or radish, you’ll need a 12 inch deep container. If you’re growing a herb such as cilantro, you would be fine with a 6 inch deep container.
How wide should the container be?
The vegetable plant you grow will mature to its final size, having a certain width. Some plants and varieties will be bigger than others. A recommended guideline is for the width or diameter of a container to be half of the mature height of the plant.
For instance, carrots and radishes can grow in a container with a 6-inch width, as they typically grow up to 12 inches in height. Tomatoes require a larger pot size of 12 inches in width, as they can grow up to 24 inches tall.
How many plants can you put in a container?
Typically, we can grow one plant in a pot ranging from 3 to 5 gallons in size. A 7 to 10 gallon pot can accommodate the growth of 2 plants.
It’s possible to cultivate three plants in a pot with a capacity of 10 to 15 gallons. The number of plants that we can grow in a pot is determined by the spacing and depth requirements of the plants.
I’ve written a detailed guide that will give you information about 100 plants and how many you can grow in a container.
Does container size affect plant growth?
Container size will affect plant growth because it determines the potting soil and nutrients it will hold. If the container is too small for the vegetable plant, it won’t get the required space and nutrients to grow well. The small container will hold less potting soil and it can lead to underwatering if you don’t water it often.
If the container is too big for the vegetable plant, there is a risk that the potting soil will hold excess moisture. The small plant’s roots are insufficient to absorb all the moisture. This can lead to overwatering and root damage.
The large container will hold a lot of potting soil, which can weaken the stability of the plant because of the loose nature of the potting soil.
So, you want to pick a container that a good enough size depending on the vegetable plant but not too large or too small.
Choosing the right container size is one of the important factors for a successful container garden. There are other basic things you need to be aware of when starting a container garden that you’ll find at the post below.