The Best Size for a Raised Bed Garden Depends on Your Space

Thanks to simple DIY raised bed tutorials and the wide array of raised beds available for purchase online, it's easier than ever to find a raised bed that will fit in your space.

If you're looking to add some raised garden beds to your outdoor space, we recommend using both the size and shape of the space you have available to determine the optimal size and shape of your raised beds. This will help you create a kitchen garden design that's as practical as it is aesthetically pleasing.

Before we explore the steps to determine the best size of raised beds for your particular space, let's review general guidelines for raised bed garden dimensions, including the best width, length, and depth for your raised garden boxes.

The Best Raised Garden Bed Width

The width of your raised beds can potentially be limited by the space you have available. (Don't worry—we'll help you figure out how wide you can go by following the steps below.)

The ideal raised garden bed width is between 18 inches and 4 feet.

Anything more narrow than 18 inches across won't give you enough room to take full advantage of growing in raised beds. You'll only be able to plant one to two rows of plants, depending on how much each plant needs to spread out. Beds that are at least two feet wide are preferable because you'll be able to fit more rows of plants (and that means you'll get to harvest more yummy stuff from the space).

When to Pick a More Narrow Raised Bed

If you need to install your raised beds next to a wall or fence and will, therefore, only be able to tend from one, two, or three sides, it's best to stay under two and a half feet in width. That's probably about as far as your arms can comfortably reach to tend and harvest from plants.

When to Pick a Wider Raised Bed

If you're able to access your raised garden beds from all sides, then you can go as wide as four feet. Anything beyond four and a half to five feet typically makes plants in the middle of the bed too difficult to reach without stepping into the bed. One of the benefits of growing in raised garden beds, after all, is ease of tending, so it's important to take into account the maximum recommended width of your beds.

So just remember to select your width based on where the raised bed is going.

If it's up against a fence or home, the maximum recommended width is two and a half feet.

If there will be access on all four sides, the maximum recommended width is four feet.

The Best Raised Garden Bed Length

Like width, the length of your raised bed will be determined by the space you have available and the materials you'd like to use to build your bed.

The ideal raised garden bed length is between 4 feet and 10 feet.

If you're using wood to construct your raised beds, eight-foot-long boards are generally the most economic option. That's why many of the raised beds you'll see in our designs just happen to be eight feet in length. (Our ideal piece of wood is a 2in. x 6in. x 8ft. cedar plank based on availability, affordability, and durability.)

If you're building a raised bed out of stone, brick, or steel you have a little more flexibility for length.

In my experience, the best length for a bed maxes out around 10 to 12 feet long. Anything longer than that and the beds are liable to bow.

We installed two 20-foot-long wooden raised beds for a Rooted Garden client in Houston. Our carpenter had to build reinforcements inside the bed to ensure the structure would hold together once the heavy soil was added. (Learn more about this garden design here.)

The Best Raised Garden Bed Depth

Unlike the first two dimensions, the height of your raised bed doesn't need to be determined by your available space. A raised bed should be tall enough to accommodate the full root ball of whatever plants you're growing. The minimum raised beds depth I ever recommend is six inches (which is deep enough to grow greens and herbs). One foot is enough to grow root crops and medium-size plants, and 18 inches is deep enough to grow pretty much any kitchen garden plant.

Most of the raised beds we design for our Rooted Garden clients are two feet tall. The extra height is mostly just for the ease and convenience of the gardener. Garden work should be an enjoyable part of your daily routine, not a chore that hurts your knees and back. I also prefer this height for aesthetic reasons. Two feet of stone, brick, Corten steel, or cedar planks adds so much beauty to a space.

There's no reason to go over two feet unless you have a specific reason, such as a mobility issue.

Keep in mind that the deeper your raised beds, the better the drainage you'll have for your plants. Read more on how deep your raised garden beds should be.

To see the difference in heights, here are one-foot-tall raised beds surrounding a center grouping of two-foot-tall raised beds.

How to Determine the Best Raised Bed Garden Size for Your Space

Follow these steps to determine the best size of raised beds for your space.

Step One:

Determine your kitchen garden location.

Step Two:

Measure your total available area.

Step Three:

Select your kitchen garden layout.

Step Four:

Subtract borders and walkways.

Step Five:

Calculate ideal length and width for each raised bed.

Now, let's look at a breakdown at each of these steps.

Determine Your Kitchen Garden Location

There are several factors to consider when choosing the best location for your kitchen garden, including hours of sunlight, convenience of access, proximity to a water source, and aesthetics. Your garden will need to receive six or more direct sunlight hours per day, all year. Try to position your garden on the south side of any tall structures (homes, sheds, fences, trees, etc.) if you're in the Northern Hemisphere. Learn more about how many hours of sun a vegetable garden needs and how to choose the ideal location to place your raised-bed garden.

Measure Your Total Available Area

Grab a measuring tape and determine how much growing space is available in the area you've selected for your raised-bed kitchen garden. Measure the width and length of this space. I like to draw it out on graph paper so I can see what I'm working with.

Select Your Kitchen Garden Layout

This is a big step. The layout you select will play a large part in the ultimate size of your raised beds.

We try to avoid what I call the awkward single gardens. You know, when there's just one raised bed hanging out by itself. We typically design spaces so that raised beds come in pairs or trios.

That's not to say that you can't set up a single raised bed. The cedar raised bed pictured alone still looks beautiful in the space. Its size (it's 3ft. wide x 8ft. long x 2ft high) and the use of the panel trellis help to lend enough visual weight to this raised bed so that it can stand alone without feeling awkward.

Kitchen Garden Layouts

Let's look at some of the different kitchen garden layouts and discuss the best sizes of raised beds to use within each.

• border garden
• twin gardens
• garden trio
• four-garden classics
• formal potager

Border Gardens Need 2ft. x 6ft. of Space

The border garden, our most popular layout, works well against a fence or home. This layout is ideal for making the most out of smaller outdoor spaces, especially those areas that were previously underutilized (that random strip next to the driveway or a narrow area between the house and the fence).

You’ll need a minimum of 2 feet of width and at least 6 feet in length available to make the most of a border garden. Since one side of the garden is typically up against a structure and not accessible, you generally shouldn't consider installing a raised bed that's wider than 2.5 feet.

Read more about how border gardens are the perfect solution to small garden design.

Twin Gardens Need 8ft. x 13ft. of Space

If you've got a little bit larger area to work with, we think everything works well in pairs. Again, we usually don't want just one garden in the middle of the yard by itself, unless the landscape just doesn't allow for two.

Twin gardens provide a symmetrical layout (because both beds should be the same size) and make the most of a yard that’s deeper than it is wide (or wider than it is deep). The best raised bed sizes for twin garden layouts are 4 feet by 4 feet, 6 feet, 8 feet, 10 feet, or 12 feet, depending on how long your space is. Remember, going 4 feet wide assumes that you'll be able to access these beds from all sides.

The raised garden beds pictured below are each 11.5ft by 3.5ft by 2ft for a total of 80.5 square feet of gardening space. (Learn more about the design elements in this garden.)

Garden Trios Need 15ft. of Width

There's a reason interior designers often group things in threes. Garden trios are perfect for a space that's very long or that's roughly circular in shape. If you're aiming to place your raised beds in a circle, be prepare to get creative with your building material and note that you'll need at the very least a diameter of 15 feet.

(Learn more about this garden design here.)

This garden trio makes use of the long strip of available growing space along a fence. Since these beds are really only accessible on one side, we kept them at 2.5ft. wide.

Four-Garden Classics Need 15ft. x 15ft. of Space

If you have a space that’s square, or nearly square, in shape and at least 15 feet wide, you have room for four raised garden beds arranged on a grid.

In a four-garden classic, each of the four raised beds should be the same size, typically 4 feet wide and 4 feet, 6 feet, or 8 feet long.

(Tour more four-garden classics here.)

Formal Potagers Need 20ft. x 20ft. of Space

If your landscape allows for a total garden area that’s more than 20 feet wide and long, you have space to create a formal potager. These designs are large, unique, and often ornate (thus the fancy-sounding name).

The raised beds in this large garden layout are often L-shaped (which means they need to be custom built). We like to add an extra square-shaped raised bed or another focal point like a fountain, a fruit tree, or a sitting area in the middle.

The best raised bed garden size for this type of layout is typically 3 feet wide and 10 feet long on the longer side of the L.

Subtract Borders and Walkways from the Total Growing Space Available

All right, you've measured your available space and chosen a garden design layout that will fit inside that space. Before you know exactly how wide and long your raised beds can be, it's important that you subtract feet for your pathways and borders.

Garden pathways should be 2 to 3 feet wide (wide enough to fit a wheelbarrow through, if needed, and to be able to easily maneuver yourself around). For a border garden, make sure you're leaving about a 1.5- to 2-foot-wide border so that you can step up to the bed comfortably.

Learn more about garden pathways.

Calculate Ideal Length and Width for Each Raised Bed

Figure out how wide and long each of your raised beds can be based on the remaining available growing space.

Let's say you have a space that's 10 feet wide and 14 feet long in a sunny spot in your yard that you'd like to use for your garden. You could do twin raised beds that are 2 feet wide and 10 feet long and separated by a 2-foot-wide pathway. That would give you two feet around the perimeter of the garden so you can access the garden from all sides.

If you're not going to build your own raised beds to your exact specifications, look for options that are in your ideal size range when you're shopping around.

Common Raised Bed Garden Sizes

As a general rule, raised beds are typically between 1.5 and 4 feet wide and between 4 and 10 feet long. Common raised bed garden sizes include:

• 4' x 4'
• 2’ X 8’
• 4' X 6'
• 4' X 8'
• 2' X 6'
• 4' x 10'
• 2' x 10'

I have step-by-step instructions (with helpful pictures) to build our most popular DIY raised bed, a 4' x 4' x 1' wooden garden bed, which gives you a total of 16 square feet of growing space. I also include modifications so you can build the following sizes:

• 2’ X 8’ X 1’
• 4' X 4' X 6"
• 4' X 6' x 1'
• 4' X 8' X 1'
• 2' X 6' x 1'

You can easily adapt these directions to build taller beds, just keep in mind that your budget will basically double.

The six raised beds in my own kitchen garden (pictured below and featured in my book, Kitchen Garden Revival) each measure 2.5' x 7' x 2'. You can find the step by step to build my raised beds, complete with top trim, plus a supply list, in my book or in our easily downloadable ebook, The Complete Guide to Gardenary Raised Beds.

Find Answers for All Your Raised Bed Questions Here at Gardenary

If you're feeling stuck or intimidated over creating your own raised-bed kitchen garden, you're not alone. Gardenary exists to give beginner gardeners a place where they can find all the resources they need to keep on growing.

If you're a DIY'er, my book, Kitchen Garden Revival, delves deeper into picking a location for your kitchen garden and then walks you through the planning, designing, and building of your raised beds, plus how to plant and tend your favorite edible plants.

If you're more an online-course-type of person, check out our popular course, Kitchen Garden Academy. Over the course of eight modules, we walk you through the complete step by step to set up and grow in your own kitchen garden.

For maximum help setting up your own kitchen garden, find a garden consultant near you to come out to your space.