Are you ready to start a container garden but aren’t sure how deep of a container you need to grow vegetables?
The depth and size of your container is one of the most important things to remember when starting a container garden. There are so many different-sized containers and pots to choose from and different vegetables will have vastly different needs.
Then you’ll have to consider the space and goals for your container garden. Do you have enough room to grow large root crops? Or will you have to use more creative methods for an awkward space?
After you decide on your container gardening goals, make a list and cross out the ones that aren’t feasible for your space.
As a General Rule, Bigger is Better
If you’re ever unsure about if a pot is big enough to grow in, just remember that bigger is generally better. In pots that are too small, the roots may become root-bound and cannot properly take in nutrients from the soil. This can lead to stunted growth or starvation. A higher soil volume means:
- Less watering for you. A higher soil volume will keep water moisture levels stored for longer.
- Room for friends. Add companion plants or bright flowers to attract pollinators and repel pests.
- More soil nutrients. Helps feed the plant nutrients over time for higher production and yield.
Standard Clay and Plastic Pot Sizes
| How Deep is the Pot? | Amount (Gallons) | How Much Soil Do You Need? |
| 5-6 inch | 1-quart | 0.03 cubic ft of soil |
| 7-8 inch | 1-gallon | 0.15 cubic ft of soil |
| 10-inch | 3 gallon | 0.46 cubic ft of soil |
| 12-inch | 5 gallon | 0.77 cubic ft of soil |
| 14-inch | 7 gallon | 1 cubic ft of soil |
| 16-inch pot | 10-gallon | 1.5 cubic ft of soil |
| 18-inch pot | 15 gallons | 2.3 cubic ft of soil |
The height of the vegetable can also be used to dictate the size of the pot. For every foot in height, you also add a gallon to the container. For example, for a tomato plant that can grow up to 4-5ft, a 5-gallon container would be ideal. The larger the vegetable, the larger the container you will need.
Use this table as an estimate of how much soil you need, depending on your pot. As a beginner, it’s important to start small! This will help keep you from feeling overwhelmed and frustrated. Over time, you can gradually increase the size of your garden and even save on buying soil by making your own compost.
Which Vegetables Do Well Growing in Containers?
I am an avid believer that any vegetable can be grown in a container. However, there are two things you have to take into account: the plant’s root system and the size at maturity.
Here’s a guide for the most common vegetables and the ideal size containers to grow them in. To be sure, research varieties that are specifically bred to be smaller or grow in containers. A lot of the time, this will be right on the packet!
6-inch pot
- Herbs (Cilantro, Dill, Mint, Rosemary, Oregano, Thyme)
- Garlic
- Lettuce (some varieties)
7-8 inch pot
- Cucumbers
- Peppers
- Bush Beans
- Green Onions
12-inch pot
- Eggplant,
- Radish,
- Pole Beans,
- Beets,
- Onions
5-gallon buckets
- Tomatoes
- Potatoes
- Carrots
- Squash varieties
16-18 inch pot
- Broccoli,
- Cabbage
- Cauliflower
- Squash
Note: A 5-gallon pot (12-inch pot) is not the same size as a 5-gallon bucket. ‘Gallon’ sizes for nursery pots tend to be slightly smaller than standard U.S. gallons. A 5-gallon pot is only a little over 3 gallons, while a 5-gallon utility bucket will hold a literal 5 gallons. Sizes also vary depending on the manufacturer so this is why going bigger is generally better!
And remember, you don’t have to use actual pots to start a container garden. As long as your container can accommodate the plant size and root, you can pretty much use any container you need to grow vegetables that you can find around the house. This includes storage bins, trash cans, juice containers, grow bags, etc.
Final Thoughts
I hope this post was useful and helped you decide what size container you need to grow vegetables! If you think that anyone can benefit from this information, please share!
Want more container gardening tips, tricks, and ideas? Be sure to follow me on Pinterest!
