What’s the best dimension for a raised bed? Raised beds come in different sizes; which ones work best with your outdoor space? You want to make sure that each raised garden bed is sized just right for the space and the style works well with your outdoor aesthetics.
From our previous blog, “What is Raised Bed: An Introduction to Raised Bed Gardening”, we have discussed the use of raised beds and the benefits of using them in gardening. In this article, we will continue our discussion about this garden box and help you decide on how to choose the right one for your plants.
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Factors To Consider in Raised Bed Sizes
Here are some of the most important factors to consider when it comes to raised bed sizes:
- Length
- Width
- Height
What is the ideal size for a raised bed?
The average size for a raised bed is about 3 to 4 feet in width and about 6 to 10 feet in length. This size works well in small and large spaces alike, and it allows easy access to the plants. With this size, you don’t have to strain too hard to remove the weeds, work the soil, and water the plants.
It’s best to keep the size of the raised bed to a maximum of four feet if you don’t have a lot of space for one. If the beds are set against a fence or a wall, they should be about 2 to 3 feet wide so you can reach the farthest side without losing your balance or hurting your back.
What is the ideal height for a raised bed?
Ideally, the raised should be at least 10 to 12 inches in height. It should be at least 8 to 12 inches deep. For vegetables, most raised beds are 12 to 18 inches deep. If drainage is an issue, you can go deeper or simply use a porous growing medium. If you’re building the raised beds yourself, the beds should slope to about 2% away from any structure to minimize the risk of standing water.
The height will depend on the location of the raised bed. If, for example, you are setting the raised bed on a hard surface, it should be deep enough for plants to root. If it is too shallow, the roots would reach the subsoil and hit the hard surface, which could stunt the growth of the plants.
What’s the most popular height for raised garden beds?
The most popular size is 11 inches, the height of two standard 2 x 6 inches boards. At 11 inches, the raised bed provides sufficient drainage for most crops.
One thing to keep in mind when choosing a raised bed - the taller it is, the more volume it will hold. When the soil has been watered, it becomes heavy and puts a lot of pressure on the structure. This could cause the raised bed to bow outwards in the mid-span, near the top. You’ll need a cross-support installed at the center of the span if your raised beds are taller than 12 inches and longer than 6 feet. The support will prevent the raised beds from bowing.
Other Important Tips to Remember in Raised Bed Gardening
- Most garden crops need at least 10 inches of soil to grow
- If your raised garden bed is lower than 10 inches, till the existing soil below the raised bed
- The minimum required height for raised beds set on a hard surface is 10 inches
- For wheelchair access, raised beds should be at least 24 inches tall
- If you have a bad back, the raised bed should be 36 inches off the ground
- If you have kids, the raised beds should be closer to the ground
- Deep rooting crops like sweet potatoes, tomatoes, watermelon, and squash need a raised bed with 24 to 36 inches of depth.
Different plants require different raised bed depths. It’s essential to check the raised bed requirements of different crops before building one or buying a raised bed.
Frequently Asked Questions About Raised Beds
1. What is the best size for raised beds?
The answer depends on the plants or crops that you will grow with your raised garden bed. Essentially, make sure that your garden box has enough space, so best to keep a maximum of 4 feet wide and minimum of 6 inches long.
ECOgardener offers 2x4, 2x8, 4x4 sizes of raised bed planters.
2. How many bags of soil do you need to fill your raised bed?
For ECOgardener 2x8 raised garden bed, it will take about 12 bags (1 cubic feet each) of raised bed soil to fill it almost full.
3. Is 6 inches deep enough for raised beds?
No. The basic height for raised beds is 6 inches and most plants or vegetables need a minimum soil depth of 6 inches. So for your raised beds, it's better to choose 8 to 12 inches deep.
