How to Build a Raised Garden Bed

Planning, Building, and Planting a Raised Garden Bed

raised-garden-bed

Learn how to easily build your own raised garden bed!

Crestock

Raised garden beds are fairly easy to construct, even easier to maintain, and offer myriad benefits for your garden! Here’s how to build a raised garden bed in your backyard, as well as advice on using the right wood and soil.

Raised beds are an easy way to get into gardening! Whether you purchase a kit or build your own, there are some great reasons for raised bed gardening, which we highlight below.

What is a Raised Garden Bed?

A raised garden bed is a large planting container that sits aboveground and is filled with soil and plants. It is a box with no bottom or top—a frame, really—that is placed in a sunny spot and filled with good-quality soil—to become a source of pride and pleasure, and a centerpiece of the garden.

Why Should I Build a Raised Garden Bed?

Raised garden beds have many benefits. Here are a few reasons why you should consider using one:

  • Garden chores are made easier and more comfortable thanks to less bending and kneeling. Save your knees and back from the strain and pain!
  • Productivity of plants is improved due to better drainage and deeper rooting.
  • Raised beds are ideal for small spaces where a conventional row garden might be too wild and unwieldy.
  • Planting in a raised bed give you full control over soil quality and content, which is especially important in areas where the existing soil is rocky or nutrient-poor.
  • Raised beds allow for a longer growing season, since you can work the soil more quickly in the spring in frost-hardened regions, or convert the bed into a cold frame in the fall.
  • Fewer weeds are seen in raised beds thanks to the bed being elevated away from surrounding weeds and being filled with disease- and weed-free soil.
  • Raised beds allow for easier square-foot gardening and companion planting.
  • Learn more about the benefits of raised garden beds

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Best Wood for Raised Beds

Many people are concerned about the safety of their wood frame. First, rest assured that CCA pressure-treated wood is banned, as it was known to leach arsenic. To ensure that the wood lasts, there are several options:

  • Regular pressure-treated lumber sold today has a mixture of chemicals applied to prevent the moist soil and weather from rotting it. Although pressure-treated wood is certified as safe for organic growing, some people have reservations about using it, and there are various eco-friendly alternatives. 
  • More expensive woods, such as cedar, contain natural oils which prevent rotting and make them much more durable. They are more expensive to buy, but they will last many more years.
  • Choosing thicker boards can make the wood last longer. For example, 2-inch-thick locally sourced larch should last 10 years, even without treatment.
  • Avoid using railroad ties, as they may be treated with creosote, which is toxic.

Alternatives to wood include concrete blocks or bricks. However, keep in mind that concrete will increase the soil pH over time, and you will have to amend the soil accordingly to grow your best garden.

Size of Your Raised Garden Bed

  • First, you need a location that has level ground and gets the right amount of sunlight (6 to 8 hours per day).
  • In terms of bed size, 4 feet is a common width. Lumber is often cut in 4-foot increments, and you also want to be able to access the garden without stepping into the bed. Making the bed too wide will make it difficult to reach the middle, which makes weeding and harvesting a pain.
  • Length isn’t as important. Typical plots are often 4 feet wide by 8 feet long or 4 feet wide by 12 feet long.
  • The depth of the bed can vary, but six inches of soil is a minimum. Plants need at least a 6–12-inch rooting zone, so 12 inches is ideal.
  • Before you establish the bed, break up and loosen the soil underneath with a garden fork so that it’s not compacted. Go about 6 to 8 inches deep. For improved rooting, some gardeners like to remove the top layer (about a spade’s depth), dig down another layer, and then return the top layer and mix the soil layers together.

Building a Raised Garden Bed

  • To support timber beds, place wooden stakes at every corner (and every few feet for longer beds). Place on the inside of the bed so that the stakes are less visible.
  • Drive the stakes about 60% (2 feet) into the ground and leave the rest of the stakes exposed aboveground.
  • Ensure that the stakes are level so that they’re in the ground at the same height, or you’ll have uneven beds.
  • Set the lowest boards a couple inches below ground level. Check that they are level.
  • Use galvanized nails (or screws) to fix the boards to the stakes.
  • Add any additional rows of boards, fixing them to the stakes, too.

Check out our video on how to build raised beds for your vegetables:

Soil for Raised Garden Beds

The soil blend that you put into your raised bed is its most important ingredient. More gardens fail or falter due to poor soil than almost anything else. 

  • Fill the beds with a mix of topsoil, compost, and other organic material, such as manure, to give your plants a nutrient-rich environment (see recipes below). Learn more about soil amendments and preparing soil for planting.
  • Note that the soil in a raised bed will dry out more quickly. During the spring and fall, this is fine, but during the summer, add straw, mulch, or hay on top of the soil.
  • Frequent watering will be critical with raised beds, especially in the early stages of plant growth. Otherwise, raised beds need little maintenance.

Raised Bed Soil Recipe

For a 4x8-foot raised bed:

  • 4 bags (2 cubic feet each) topsoil (Note: Avoid using topsoil from your yard, as it may contain weeds and pests.)
  • 2 pails (3 cubic feet each) peat moss
  • 2 bags (2–3 cubic feet each) compost or composted cow manure
  • 2-inch layer of shredded leaves or grass clippings (grass clippings should be herbicide- and fertilizer-free)

Makes enough for a depth of about 9 inches.

Raised garden bed. Photo by Oregon State University/Wikimedia Commons.
Square-foot gardening in a raised bed. Photo by Oregon State University/Wikimedia Commons.

Planning the Raised Bed Garden

To plan out the perfect garden for your space, try the Almanac Garden Planner! In minutes, you can create a garden plan right on your computer.

The Garden Planner has a “Raised Garden Bed” feature. It also has a specific square-foot gardening (SFG) feature, which involves dividing the bed into squares to make the organization of your garden a lot simpler (see photo, above).

Which ever garden you select, the Garden Planner will show you the number of crops that fit in each space so you don’t waste seed or overcrowd. There’s even a companion planting tool so you plant crops that thrive together, not plants that inhibit each other.

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Right now, we’re offering a free 7-day trial on the Almanac Garden Planner—enough time to plan your first garden. If you enjoy the Garden Planner, we hope you’ll subscribe. Otherwise, this is ample time to play around and give it a go!

Learn More

Have you ever thought about building your own raised garden bed? Or do you have one already? Tell us about it below!

Reader Comments

Leave a Comment

My raised garden in Sydney NS

Constructed as a birthday gift for my wife, I built the raised vegetable bed 15L'x5'W and 14" deep from old deck placed down side up on 4"x4" deck legs. Extra 8x1 sides added to give it the 14" depth. 3/4" electric pipes were use to create arches above the bed were 40% sun blocking canopy net was placed (mostly against the almost constant wind gales) . The irrigation system is built with rain barrel as water source feed into wetness controlled ceramic cone pegs. The ceramic cone pegs have the ability to sense the wetness level underground and automatically draw what ever level of water the roots need by triggering the water valve control in the rain barrel. The rain barrel placed at 100 cm height above the raised bed to provide the require one atmospheric pressure the irrigation system requires.

Cat toilet

My cat used my raised garden bed for a cat toilet and some neighbor cats, also. Do I replace the soil I put in last spring? I have turned the soil in the bed.

cat toilet

You don't need to replace the soil, but wash your hands thoroughly after gardening and wash your produce well too. If pregnant, be especially careful due to risk of toxoplasmosis.

I lay sticks in a criss cross pattern over bare soil to discourage cats from enjoying my nice loose garden soil for a toilet. Luckily my cat thinks it is uncivilized to go in the outdoors, but there are some ferals in the area.

Raised Beds on Legs

This year I had to remove my raised beds to make room for a goat barn. I've decided to build new beds on legs, approx. 12" off the ground. My previous beds would fill with wire grass (Bermuda?) so bad every year it was impossible to keep them out. Landscape fabric didn't do a thing to block it. So now I'm building off the ground to avoid that issue. What I'm wondering is how high do the bed sides need to be since they're completely off the ground and won't have the benefit of the ground soil below? Will 12" of soil be enough? I had thought I'd use hardware cloth and landscape fabric in the bottoms with 2x4 supports every few feet to hold the soil's weight. I plan to build each one 4 ft x 8 ft x whatever height I need for soil. Any suggestions on height?

Raised Bed Height

Making them 2 to 3 feet deep would be ideal. To grow the healthiest plants, 2 feet is great, but if that’s too deep for you, 18 inches is fine. 

plastic sides in place of boards

Is it OK to use plastic boards for the sides? I'm thinking of the type of recycled plastic that is often used for benches or boardwalks these days. They seem very sturdy and of course won't rot. But do they leach chemicals? I see them often use das boardwalks in sensitive-drainage areas e.g. wetlands.

Bindweed

Been killing about a 10' x 10' patch of bindweed in part of my garden plot. I have dug, tilled, pulled, and finally sprayed with Hi-Yield 2,4-D Amine a selective weed killer". It's still growing and coming back. I'd like to make a raised strawberry patch in this area. How oh how can I rid myself of this horrible weed whose roots can go to 40' depths I'm told! And how do I put my berries above this pest and not have the weed come up and in to the patch? Thank you for help and advice!

nasty bindweed

I would not use chemical herbicideds in my veg garden, but maybe you are growing ornamentals... Have you tried smothering the soil? The problem with tilling is that you probably have hundreds and hundreds if not thousands of seeds in your "seed bank", and each time you disturb the soil, you have more seeds germinating, not to mention the roots that keep regenerating plants. I would seriously consider covering the area with newspaper and then cardboard, and putting a good 12 inch layer of clean compost and soil on top of that. Plant what you want and be vigilant about weeding. Good luck!

Raise beds but higher

I have some problems with getting around so i thought i would build some raised beds but they set off the ground about 3 feet, that is the bottom of the bed. ? is what would be the best way to do the bottom of the bed. I thought to make a inner 2x4 and attach (?) to that. Wonder if i should go with a brace wood plank system and then but in metal mesh, and some stone for drainage. Any help or suggests please send to me address emails as garden helper at subject. Believe me i have went thru this a 100 times Please i need HELP, Thank's to you all ahead of time, GOD BLESS and happy Gardening

raised garden bed and cement ruble

Hi
I am new to gardening.We had some spare materials so we are making a raised garden bed out of sheet iron/old color bond roofing. Now we are in the process of filling it.We put cement chunks on the bottom at a height of around 8inches.The sides of the bed are 20inches in height.
My question is what do we fill the gaps with around the cement pieces with?gravel? sand?or just keep filling to the top with good organic soil?
And when the bottom 8inches is filled do I ad paper or something? or just top it up with organic soil?
Thanks in advance.

raised bed materials

We are not familiar with color bond roofing; a search suggests its an Australian product, so g’day! It may work as your wall but being metal it may also heat up more than natural materials (wood, say) and so conduct heat to the soil adjacent to it. Not necessarily a bad thing; it might depend on how hot it gets…and because of heat dries out the soil. Why 8 inches of concrete? What is underneath the concrete, soil? A hard surface? Is the 8 inches of concrete instead of soil, so you can save on soil? As for filling around the concrete, do some homework on what you want to grow. Some plants need a good 12 inches of soil, minimum, but some experts recommend up to two feet of soil so plants can spread their roots. You don’t want roots up against the concrete.  The soil will pack in around the concrete; so would sand, but sand does not benefit the roots; it helps—or increases—drainage, and you don’t want water to pour out. You could spread a little newspaper over the concrete but it will not last long; it may be better to fill with good organic soil and save the paper (newspaper) for possible use as mulch. To a certain extent, this will be an experimental season for you. Let us know how it goes!

 

Waist high raised bed but with only a 12 inch depth

We are changing over from a straw bale garden to a wood raised garden. Has anyone seen any free designs for a raised bed that is about 3 foot high but only want the depth of the bed to be about 12-15 inches? My husband is concerned about the best method to stabilize the bed since it will not be supported "by the ground", but elevated. Any ideas? Thank you.

Old tires for raised bed garden

Has anyone tried stabilizing old large tires for a raised garden bed? Is the rubber safe for use when growing food? I want to build a raised bed that will save some wear&tear on my lower back. I also prefer finding new uses for products to help reduce our ever growing landfills. This would also be economical for me. Thank you.

Old Tire Raised Bed

Hi Cynthia,

In the short term, yes you can make a planter out of old tires. However, over time the tires will degrade and release toxic carcinogens into the soil. If you want to use the planter for more than a year, it’d be a better use of your time to use a material other than tires. 

soil in an elevated bed

I plan to make elevated beds for my vegetables and wanted to know if my choice of soil mix is suitable. Equal parts if Composted manure, shredded peat, and vermiculite. I also have earthworms I want to add.

Soil Mix

Hi Dedria,

The soil mix you describe is essentially a potting soil mix, which has excellent drainage. The peat will make the soil slightly acidic, so keep that in mind when deciding what to plant. Also, depending on where you live, consider the climate; your climate may be dry and hot, wet and humid, or anything in between. Your mix is good for wet regions, draining well and not retaining too much moisture. If you live in a dry region, you’ll want some topsoil or a higher ratio of compost to peat and vermiculite to retain more moisture. Lastly, it is a good idea to get a mixture of different kinds of compost for a mix like this, as compost from one source will be lacking certain nutrients. We hope this helps!

Raised beds

Are boards of Juniper suitable for raised beds?

First time gardener

I built four 4x8 untreated pine raised garden beds. They are about 12 inches deep. I added hardware cloth and cardboard on the bottom of the beds to prevent critters and weeds. I am concerned that they are not deep enough for all kinds of vegetables to grow. Any tips/advice?

Raised gardens soil depth

Six inches is a minimum. Plants need at least a 6- to 12-inch rooting zone, so 12 inches is ideal. All the best with your garden harvest!

First Time for Raised Bed

My hubby and I have decided to give the raised bed a try in our garden this year; he'll be 75 in 1 month and I turned 71 just 2 months ago. Thanks for the great info on building raised beds, it came at the perfect time for us. We always raise 2 large gardens (about 1/2 acre total) of berries and vegetables so we do a lot of canning and freezing; we want to try our hand at home freeze-drying some of the fruits and vegetables this year. Hope the raised bed will make the gardening chores - weeding & harvesting - much easier on our old backs this yr. All our watering is done with the black soaker hoses - similar to a drip-system - and I'm sure that will work great for raised beds. Thanks again for the great info.

making those beds . . .

Thanks for the kind words, Thelma! Here’s hoping that you and your husband have a delicious and hefty harvest!

Small raised beds find space in sloped yard

My yard is on the side of a hill, with some very tiny areas that are only "sort of" flat. Small raised beds placed in the few level-ish areas have allowed me to have productive garden space without having to worry about my garden being washed down the hill during a heavy rain. In fact, I have managed to find appropriate places for six 4 foot by 4 foot raised beds. That is 96 square feet of garden space. My family, friends, and neighbors enjoy the vegetables from these small raised beds.

beds on slope

Good for you, Maria! We hope that other gardeners who read these comments take inspiration—and confidence—from your success. Thanks for sharing!

More advantages to raised beds.

In warm climates like we have here in southwest Florida nematodes can be a real problem. At this point there is no effective chemical control for these microscopic worms available to the residential gardener; however raised beds do offer the great advantage of easy solarization. During the off season when the beds are fallow, cover them with a heavy gauge, UV resistant plastic sheet and secure it well so that it doesn't blow away. The plastic should extend all of the way to the ground on the outside of the bed. This works very well in warm climates because the temperature inside of the bed can reach temperatures of up to 150 deg/F on a hot summer day. Temperatures that high will kill virtually every seed, insect egg, bacteria, mold spore, some viruses, and nematodes. Our fallow time here is in the summer, so this method is probably not too effective in colder climates when the summer is the height of growing season.

nematode nemesis!

Thanks for taking the time to share this great advice, Rononpi! You have clearly found a success method for defeating the problem of nematodes, and it’s highly likely that other gardeners will find this information helpful. We certainly did! All the best—

FL follow-up.

I am in South Florida as well. How deep are your beds... and What do you recommend putting below the soil to help with water retention?

Mixing bed soil with existing soil

Thank you for this informative page! We've had a garden in the ground the last three years and weeds& pests (rabbits, slugs, deer) have always been a problem. This year we're interested in trying raised beds to deal with both. I read here you recommend mixing clay- rich ground soil with the soil/mix put into the beds, but that will just perpetuate the weed problem I think. Any tips? We plan to put chicken wire on the bottom of the frames to keep out burrowing rabbits (happens with our regular garden fence) and the cardboard on top sounds like a good idea for weed suppression. But those two things are at odds with mixing soils too. Finally, any tips for pest fencing around the beds themselves that are easy to work with? Thank you!

beds...

Above we recommend

  • Fill the beds with a mix of topsoil, compost, and other organic material, such as manure, to give your plants a nutrient-rich environment.

Clay may be mentioned below re particular issues.

As for protecting your bed, it is entirely possible you may have to fence it in. Being raised does not eliminate pest problems; for materials, it’s your call re aesthetics and practicality, from chicken wire to cottage picket.

Or weeds. Weed and other seeds can blow in, birds drop them (or excrete them)—they can come from anywhere. To (almost) eliminate weeds, mulch.

Garden Too Shallow

Hello,

Thank you for your informative article.

I bought some seedlings and I have planted them. However, I suspect my garden is too shallow.

How can I make it deeper without affecting the seedlings?

Thanks

Deepening Your Raised Beds

Use a spade fork to very gently loosen the soil beneath your seedlings. You can temporarily remove them from the raised bed while you amend the soil depth. Lift the plants (keeping the roots in soil) and store them in trays, tubs, or buckets for the hour or so it takes you to work the bed. Replant as soon as possible and water well. Be sure not to bury the stems too deep when replanting. Keep the disruption of stems and roots to a minimum.

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