If you have never tried to build a raised garden planter before, it may seem like a difficult project to tackle. However, building raised garden beds out of wood is actually very easy and budget-friendly. Anyone with a drill, screws and a few lumber boards can do it! (I’ll show you how!)

Before the COVID-19 pandemic hit, I had hardly gardened a day in my life (let alone build a raised garden bed). The combination of being stuck at home with nothing to do, and the anxiety of going to the grocery store inspired my husband and me to build our own backyard garden. Any excuse to get out of the house, spend time outside, and grow our own food!

If we could figure out how to build our own raised garden beds so can you!

Are Raised Garden Beds Better for Plants?

Yes! Raised beds are a great way to grow a wide range of plants in your garden. It is much easier to grow plants in raised garden beds or pots rather than directly in the ground.

The soil stays warmer and aerated above ground, which is crucial for plant root health and growth.

Raised garden beds also provide better drainage, make weeding easier, and acts as a barrier for pests like snails and slugs.

What Vegetables Grow Best In Raised Garden Beds?

You can grow almost anything in a raised garden bed. However, there are a few vegetable varieties that do particularly well when grown in raised beds, including:

• Roots
• Leafy greens
• Onions
• Tomatoes (also do great in pots and containers)
• potatoes

How Big Should A Raised Garden Bed Be?

Raised garden beds can be as large or small as you like. However, there are a few basic guidelines when it comes to garden planter size to keep in mind.

How Tall To Build Raised Garden Beds

Raised garden beds don’t need to be very tall to be effective.

8”-12” tall is enough to grow most plants and crops.

However, vegetable beds need to be a little taller. (about 12”-18”)

How Deep To Build Raised Garden Beds?

If you plan to build a raised garden bed against a fence or wall, they should only be about 2’-3’ deep (max) because you will only have access to the garden planter from one side.

The average human reach is only about 2′-3′, so any planter deeper than that will make it difficult to access plants in the center.

If you are able to access your raised garden bed from all sides, it can be up to 4’ deep.

How Much Space Between Raised Garden Beds?

Don’t forget to leave enough space between your raised garden beds so you can easily access navigate around them.

About 2-4 feet (60cm) between raised garden beds is ideal if possible.

How much does it cost to build raised garden beds?

The cost to build raised garden beds depends on several factors.

The type of lumber, fluctuating material costs, and what you fill them with all play a key role in how much a raised garden bed will cost.

(If you don’t feel like building your own wooden raised beds, here are some affordable options)

How Much Lumber is Needed For Raised Garden Beds

The easiest way to know how much lumber is needed to build a raised garden bed is to calculate the linear square feet.

If you decide to build a taller raised garden, don’t forget to account for the height of the planter. Adding height to your linear square feet calculation is as simple as multiplying your linear square feet by the number of boards tall your planter will be.

You will also need to account for the corner posts in your calculations. The linear square feet for planter posts can be calculated by measuring the height of your planter and multiplying that number by four.

When calculating linear square feet, always add a little tolerance to the total just in case. (mistakes happen!)

It may sound silly, but don’t forget to buy a large box of decking screws to assemble your planter! Decking screws come with a special protective coating on them that prevent them from rusting over time.

EXAMPLE:

4′-0″ Wide x 4′-0″ Long planter:

4’+4’+4’+4′ (or 4’x4 sides)= 16′-0″ Linear ft

4’x4′ planter that is 2 boards tall:

16′-0″ x 2 = 32′-0″ total linear ft

Planter that is 2 boards tall, built with 2×12 lumber:

11.5″ (long side of 2×12 lumber) x 2 (boards tall) = 23″

23″ x 4 (posts) = 92″ (or 7′-8″ total linear ft)

Raised Garden Bed Lumber Sizing

I would recommend using 2×8 or 2×12 lumber boards for raised garden bed walls. You can use 1×8 or 1×12, however, thinner boards erode more quickly and will need to be replaced frequently.

Depending on the size of your raised garden bed, you can use 2×2 or 4×4 lumber for the corner posts.

*note actual lumber dimensions are different than Nominal dimensions listed

Refer to this lumber sizing chart for nominal lumber sizes vs. their actual dimensions.

Lumber Calculations for Our Raised Garden Beds

Note: To keep our project simple and cost-effective, we used standard lumber lengths for all our planters. (ex. 2′, 4′, and 8′ dimensions).

In the United States and Canada, standard lumber is milled to 6′, 8′, 10′, 12′, 14′, 16′, 18′, 20′, 22′ and 24′ lengths.

After running our own lumber calculations (see example above) the lumber needed for our project came down to this:

• (24) 2’x12”x8’ boards
• (6) 4”x4”x8’ boards
• (7) 2”x4”x12’ boards

Total Lumber Cost: About $600

What Wood Should I Use To Build Cheap Raised Garden Beds?

We decided to use heat-treated Douglass Fir for our raised garden beds because it’s durable yet budget-friendly lumber commonly used for planters.

Is it the best lumber for raised garden beds? No.

Is it pretty good? Yes.

What Kind Of Wood Is The Best For Building Raised Garden Beds?

The absolute best lumber you can use for raised planter beds is cedar or redwood. This is because cedar and redwood are both natural water, rot, and pest-resistant woods.

Cedar and redwood are also the most durable and long-lasting lumber for raised beds. The catch? Cedar and redwood lumber is by far the most expensive.

How Long Does A Cedar Raised Garden Bed Last?

Cedar raised garden beds will last about 10-15 years before they will need to be replaced.

How Long Does A Redwood Raised Garden Bed Last?

Redwood raised garden beds will last about 10-20 years before they need to be replaced.

How Long Does A Douglass Fir, Hemlock, or Pine Raised Garden Bed Last?

Douglass Fir, Hemlock and Pine will last about 5-10 years (15 if you’re lucky) before needing to be replaced.

Hemlock, fir, and pine aren’t as durable as cedar or redwood, so you will need to replace the raised beds more frequently. However, if cedar or redwood don’t fit the budget, don’t overlook hemlock, fir, and pine! They are still great affordable lumber options for raised garden beds.

Can You Use Untreated Wood For Raised Garden Beds?

Yes, you can use untreated lumber to build raised garden beds.

However, garden planters built with untreated lumber are more likely to rot quickly compared to treated wood.

With that said, untreated lumber is the most organic option for raised beds.

Is Pressure-Treated Wood Safe For Raised Garden Beds?

The debate on whether or not pressure-treated wood is ok for raised garden beds is a bit of a controversial topic.

Some argue that pressure-treated lumber is longer-lasting, and more rot-resistant than untreated lumber. Although pressure-treated lumber is by no means organic, some say it is still safe to use for raised garden beds as a way to extend their life.

However….

More argue that the chemicals used to pressure treat lumber make it an unsafe option for raised garden beds. This is because the chemicals from the pressure treating process leach into the soil, contaminating the plants in your garden.

Personally, I agree with the latter argument. It’s best to avoid using pressure-treated lumber for raised garden beds and opt for a non-chemically treated lumber option instead.

The good news is, there is a safe and equally durable option when building raised garden beds.

Safe Alternative To Pressure Treated Lumber For Garden Beds

I decided to use heat-treated Douglas fir lumber for our garden planters.

Heat-treated lumber does not contain questionable chemical compounds like pressure-treated lumber, and it is more durable than untreated lumber. Therefore it won’t contaminate your soil with chemicals, and it will last longer than untreated lumber.

The process used to heat treat lumber destroys the nutrients in the wood, making it more resistant to rot and fungi. Heat-treated lumber is also significantly drier than untreated wood. Therefore it absorbs less liquid, making it more durable and long-lasting than untreated wood.

What Is The Most Durable Raised Bed Material?

If you don’t want to go through the trouble of building and replacing raised garden beds out of wood, concrete, brick, or corrugated steel raised beds are a fantastic option.

Concrete, CMU and Brick Garden Beds

Concrete garden beds are extremely durable and don’t require regular maintenance or replacement like wood garden beds do.

It’s worth noting that although concrete requires less long-term maintenance, you will need to build the framework for your concrete form before pouring concrete garden beds. Here is a helpful video if you’re interested in making your own concrete garden beds.

If you don’t want to deal with the hassle of pouring concrete, brick and CMU are a great options for garden beds! (and they’re equally durable compared to concrete!)

Keep in mind that concrete, brick, and CMU are all more expensive when it comes to upfront material costs compared to lumber.

How Long Do Concrete, Brick And CMU Raised Garden Beds Last?

Although concrete and brick raised garden beds will eventually need to be replaced, you won’t need to worry about that for at least 10-20 years! (or more!)

Metal Raised Garden Beds

If you don’t want to deal with building a concrete, brick, or CMU garden bed, but still want a durable and cost-effective garden planter option, look no further!

Prefabricated corrugated steel raised garden beds are modern, inexpensive, easy to assemble and last a lifetime. (What’s not to love?!)

We ordered two corrugated steel raised garden beds for our own garden, and I love how durable, low maintenance, and easy to build they were!

How To Build Inexpensive Raised Garden Beds

There are literally millions of videos out there on Youtube that show you how to build a raised garden beds, so I’m not going to get into it on the weeds on this one.

In essence, you measure the width and length you want your raised garden bed to be, then cut down the corner posts and sideboards to your desired lengths and screw them all together with support posts on the inside corners. Boom! You’re done, fill your new raised bed, and enjoy!

My small budget DIY garden design inspired by The Secret Garden, combines simplicity, and efficiency to maximize the small space we had available, to create a beautiful and comfortable space we could enjoy.

After calculating how much lumber we needed (see above), and selecting the type of wood we wanted to use for our raised beds (see above), we got to work!

Large Waist-High Garden Beds

The first step in our massive raised garden bed construction was to build the waist-high back planter. This large back wall planter will act as our central anchoring point and a backrest for our benches later.

I also plan to plant some raspberry bushes in this large raised bed to create a green wall that will create sound blocking and privacy from the adjacent street.

When constructing the large raised bed, we first built the two back walls with three rows of 8′ long 2 x12 lumber and screwed them together using a central 2×4 support post.

Then we attached the two pre-constructed planter walls to our fence with decking screws. Our fence posts were cast in concrete deep below the frost line, so this will help anchor the large raised bed in place and prevent it from tipping over.

Once the back wall of the large planter was anchored, we began building the rest of the walls to enclose the large raised bed. We adjusted the height of our 4×4 structural posts as we went to keep the planter walls level, despite the slight differences in ground height.

A small raised garden bed would only need 2×4 or 2×2 posts for the corner supports, but since our planter is much larger than a typical raised bed, I beefed up the structural support to 4x4s to ensure it could hold the weight of the soil.

Along the center of our large raised garden bed, we added a few additional 2x4s as cross support to keep the posts together and prevent the walls from bowing out once filled with soil.

Once the large waist-high garden bed was complete, we moved on to the smaller raised garden beds that would flank each side.

Small Raised Garden Beds

These smaller raised garden beds are like the standard raised beds you find in DIY videos. The only difference is that these smaller garden planters attach to the large waist-high back planter wall.

I decided to stick with the 4×4 support posts for the corners and 2×4 connecting posts for the smaller raised beds since the whole structure would be pretty massive.

Similar to the large raised bed, we measured the height for the corner posts first to make sure the planter walls would be level and aligned with the large back planter walls.

Once the 2×4 connecting posts were cut to the correct height, we screwed them into the back-planter wall to act as our starting point.

We repeated the same process for the 4×4 end posts, then attached the 2×12 side planks to the support posts using a leveler to make sure the walls were level.

After we completed the first planter we moved on to building the other two planters, using the same method.

The two smaller planters that flank each side of the back-planter wall are both 2’x4’, and the middle planter is 4’x4’.

Easy DIY Outdoor Garden Storage Bench With Hinged Lid

Once the smaller raised garden beds were finished, we decided to add two storage benches in between them.

We were lacking adequate garden storage and needed to find a practical space-saving option for our problem.

Not only are these storage benches useful and comfortable, but they also provide additional structural support for the entire structure by pulling the lower raised beds together and anchoring them to the large back planter wall.

I could go into more detail about how we built these storage benches, but there’s a really great video I used for the inspiration for these benches. Check out the video here.

Essentially we built these benches by cutting 2×4 and 4×4 support posts to the height of our bench then attached them to the back and side raised garden beds to create a sturdy base for our bench. After our support posts were in place, we framed out the rest of the bench support using 2×4 lumber.

Once our bench framing was in place, we attached a 2×12 and two 2×4 boards to the 4×4 bench corner supports to enclose the storage bench.

Once the garden storage bench framework was in place, we began building the hinged benchtops.

We did this by cutting five 2×4 pieces of lumber to the length of our bench seat. (cut your benchtop with about 1/4″ of tolerance so it won’t get stuck on your sidewalls when you open it.

Once our benchtop lumber was cut to length, we cut two 2x4s to the size of our bench depth and screwed them to the underside of our benchtop with decking screws.

After attaching the 2×4 supports to the underside of the benchtop we added additional screws from the top as well. This prevents the benchtop boards from warping and pulling away from the base support.

*Note that these support pieces should be centered on the underside of your bench so that they fit inside the framed storage bench base. Check that your benchtop aligns with the opening before attaching the hinges.

When the benchtops were complete, we attached them to the storage bench framing with two hinges per bench.

Adding hinges to the storage bench seat made it easy for us to access the storage bench by simply opening the lid.

Note: When using gravel or mulch as a floor covering with a storage bench like this, account for about 2” of flooring material. A comfortable bench ranges from about 16” (min) to 20” (max) in height.

These benches are approximately 18” in height from the top of the gravel we added later, meaning we built these storage benches to be 20” above the ground without gravel. (Including the benchtop)

Building the storage benches to this height also kept the overall bench height slightly below the adjacent raised garden bed walls, giving them a nice armrest.

I recommend sealing your benchtops with a waterproof wood deck sealant to protect your storage bench from damaging UV rays that cause splintering. (ouch!)

Cheap Raised Garden Bed With Storage Benches

There you have it, How to build your own inexpensive wooden raised garden beds with convenient built-in storage benches!

If you found this article helpful like or leave a comment below and let us know! We love helping people with their home projects and want to keep bringing helpful material to our readers.

Want to Learn More?

Stay tuned for our next post, DIY cold frame! I’ll show you how to build your own garden cold frame using old windows. Cold frames are an ideal solution for early or late season gardening if you live in a colder climate, and they are also fantastic for seed germination.

You won’t want to miss out on this one, so subscribe to The Bonus Space for updates! (below or in the side bar)

You can also follow the Bonus Space on Facebook, Twitter, Instagram, Pinterest, and Youtube for more fun tips and tricks!

If you have any questions, or a helpful tip or two of your own that you would like to share about building your own raised garden beds, leave a comment below or send me an email! (Yep! I’m a real attainable person who cares about your project’s success as much as my own!)

Cheers!

Mel