Learn how to build a raised bed—cheaply and easily—for your garden. No special DIY skills required! To get started, here is a super-simple raised bed setup. We’ll also tell you what kind of material to use, how to fill a raised bed, how large a raised bed should be, and what to plant in a raised bed. Enjoy our Raised Bed Gardening Guide!
What Is a Raised Garden Bed?
A raised garden bed (or simply “raised bed”) is a freestanding box or frame—traditionally with no bottom or top—that sits aboveground in a sunny spot and is filled with good-quality soil. Raised beds are usually open on the bottom so that the plant roots can access soil nutrients below ground level.
At its simplest, you could even build a raised bed without a frame, and simply mound the soil 6 to 8 inches high and flatten the top. This requires no additional materials (beyond soil).
Benefits of Raised Garden Beds
Grouping together several raised beds makes for a substantial vegetable garden that is easy to maintain, with no weeding and crops that mature fast.
In raised beds, you will be planting seeds and transplants closer because the beds are smaller and the soil is richer. However, plants grown close together in raised beds mature faster, since they compete for nutrients and sunlight. Each plant senses the distance of others and adjusts its metabolism to compete. Several university studies have proven this “competition syndrome” by identifying how plants perceive others nearby using the green light spectrum.
Here are more benefits to raised garden beds:
- Garden chores are made easier and more comfortable thanks to less bending and kneeling. Save your knees and back from the strain and pain of tending the garden!
- 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. Raised beds help to keep things organized and in check.
- Planting in a raised bed gives you full control over soil quality and content, which is especially important in areas where the existing ground soil is rocky, nutrient-poor, or riddled with weeds.
- Raised beds allow for a longer growing season, since the soil raised above the ground warms up more quickly.
- Fewer weeds are seen in raised beds because the beds are elevated away from surrounding weeds and 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.
Choosing the Right Wood for Raised Beds
Raised beds can be made out of quite a few different materials, but the most common one is wood. However, many people are concerned about the safety of their wood frame. Rest assured that CCA pressure-treated wood is now banned, as it was known to leach arsenic, and you won’t find it in stores. Today, safely treated and untreated woods are available.
- Untreated wood will start to rot relatively quickly, depending on the type. There are exceptions, though: Cedar is the top choice for raised beds because this durable wood is naturally rot-resistant and can last 10 to 15 years. It is also insect-resistant because of oils in the wood. The downside is that it’s expensive.
- Modern treated wood has chemicals to prevent rotting. Studies have shown that any compounds that leach out are well within safe levels established by the EPA, however some gardeners feel uncomfortable with treated wood. If you are concerned about using treated timbers, line the inside of the bed walls with polyethylene.
- Another option is to simply choose much thicker boards of untreated wood. For example, a 2-inch-thick board of larch wood should last a decade without treatment.
Alternatives to traditional wood planks include:
- Railroad ties (treated) are easy because you can simply lay them on the ground and drive in iron spikes. Railroad ties treated with creosote do not appear to pose any health problems because most of the creosote has leached away.
- Pallets can be a cheap source for garden bed materials, as long as you know where they came from. Pallets are developed for shipping materials. Avoid pallets that are also treated with a chemical called methyl bromide, a known endocrine disruptive chemical which can impact your reproductive health. Most pallet producers stopped using the chemical in 2005, but many old pallets are still out there. Look for a stamp on the pallet that says “HT” or heat treated. If there is no stamp or you can’t verify an HT on the surface, don’t use the pallet in your garden.
- Stone or concrete blocks and bricks can be used. However, keep in mind that concrete will increase the soil pH over time, and you may have to amend the soil.
- Stone walls make interesting beds and have a rustic feel; if stone is easily available on your land, this could be a great option; otherwise, stone can be pricey.
- Composite wood is a newer product made from both recycled plastic and wood fibers. It’s rot-resitant and long-lasting, but also very expensive.
Another fast, cheap method of building raised beds is to use concrete construction (cinder) blocks. Their holes can be filled with soil mix and planted with herbs or strawberries. The extra gathered heat from concrete is perfect for Mediterranean-type herbs such as rosemary and lavender. Strawberry plants grow huge and fruit fast in the holes. Each block is 16 inches long by 8 inches high; the price at big box stores is most reasonable. Beds of 13 feet or longer by 4 feet wide are cheaper to build using blocks than with cedar boards.
How Big Should Your Raised Bed Be?
- We recommend a maximum of 4-feet across. (Lumber is often cut in 4-foot increments.)
- Do not go wider than 4-feet width so that you can access the garden without stepping into the bed (which compacts the soil, making it harder for plant roots to get the oxygen they need). Making the bed too wide will make it difficult to reach the middle, which makes weeding and harvesting difficult, too.
- If your raised bed is being built against a wall or fence, we recommend making it 2 to 3 feet wide, since you’ll only be able to access the garden from one side.
- Length isn’t as important. So, your raised bed can be 4 x 4 feet or 4 x 8 feet or 4 x 12 feet. Make your bed as long as you like or build multiple raised beds for different crops!
How Deep Should a Raised Bed Be?
The most basic height for raised beds is 6 inches. This is about the width of one standard 2 inch x 6 inch board. (Note that boards bought at a lumber yard are actually 1.5″ thick x 5.5” high.)
The most popular height for raised beds is about 1 foot. (If buying boards at a lumber yard, that’s 11 inches high. This is the height of two stacked “2 x 6″ boards.)
You can certainly go taller (18 inches, 24 inches, 36 inches), but note that the weight of the added soil will add pressure to the sides. You’ll need to add cross-supports to any bed over 12 inches high.
The depth of the soil itself is very important and depends on which crops you wish to grow, as well as how much soil is above the ground versus below the ground.
Shallow-rooted crops (such as lettuce, greens, and onions) need a minimum soil depth of 6 inches.
Deep-rooted crops such as carrots, parsnips, potatoes, tomatoes, and squash need a minimum soil depth of 12 to 18 inches. If plants don’t have loose soil to this depth, the roots will not be able to go down deep enough to access nutrients.
Whatever height you choose for your frame, you’ll need to loosen the soil below the ground accordingly. For example, if you have a bed that’s 6 inches high, we recommend loosening the soil below the ground about 6 to 9 more inches if you wish to grow root vegetables. If you are only growing shallow-rooted crops, there’s no need.
You can certainly build beds of different depths in your garden! If you’re growing shallow-rooted crops, it would be a waste of soil to build a bed that’s 11 inches in height.
Where to Put a Raised Bed
Before you even get started, see if you have a good location for a raised garden bed.
- Most vegetables need 6 to 8 hours of direct sunlight a day (“full sun”), especially from lunchtime onwards.
- Level, even ground.
- Close to the house for easy access for weeding and harvesting
- Do not site your bed in a windy location nor in a frost pocket.
- Soil needs to drain well, so avoid any wet or marshy areas.
Preparing the Site: “No-Dig” Aboveground Method
In spring, get ready to prepare your choosen site for raised garden bed(s).
Some gardeners will cut and roll up the turf. Many gardeners do not find it’s necessary to clear the ground as the soil will block out the grass and weeds beneath. Gardener Charles Dowding, who founded the “no-dig” method, has had great success with just adding 4 to 6 inches of organic matter onto cardboard over pasture/grass, producing masses of crops in his first year of a new bed. His philosophy is that diggingbrings weed seeds to the soil surface, creating more weeding. It hastens nutrient loss, so you’ll need to feed plants more often. And it rips apart the complex life and very fabric of your soil, reducing its ability to both drain properly and retain moisture.
Simply mow off the grass or weeds as close to the ground.
Then cover the area with cardboard which will rot down into the soil. (Make sure you pick off any tape and staples, which won’t decompose.)
Be sure to overlap the cardboard/newspaper (by about 6 inches) to ensure no weeds slip through cracks.
You’ll be adding your growing medium such as compost on top. (See how to fill your raised bed lower on this page.)
It’s fine to get on and plant immediately after setting up. By the time the roots reach the cardboard, it will have started to break down and the roots will be able to search deeper beyond that cardboard layer.
The compost that you add on top should gradually become incorporated with the soil beneath, through the actions of worms etc. Beds will need topping up with fresh organic matter (an inch or two) each fall/winter, which will help to gradually improve the fertility and health of the soil, including that below the level of the raised bed. This means you should be fine growing deeper-rooted veggies like root crops.
Preparing the Site: Digging Belowground Option
In soils that are damaged by compaction or have other problems, digging below the ground may be necessary to help build up the soil. It’s hard work if your soil is compacted but it only needs to be done once. This is most important for deep-rooted crops such as carrots which do better in soil that has been loosened and amended down to 10 to 12 inches to allow the air and water to get to the plants’ roots.
- Mark the area with a hose or string. If possible, use a leveler to make sure the ground is flat or a very slight slope (with water running away from area).
- Remove the top layer (about a shovel’s depth or 10 inches); it may be easiest to work in rows.
- Remove all rocks, old roots, and plant debris.
- Dig down a little further with the shovel (a few more inches) to just loosen up the soil.
- Mix the soil with organic matter such as compost. We recommend that the compost make up about 25% of your soil.
- Then return the top layer and mix the soil layers together.
Building a Simple Raised 4x4 Garden Bed
It’s fine to buy a commercial raised garden kit, but they can have cringe-worthy prices. You don’t need to spend that kind of money to build your own four-by-four-foot bed (or even a 20-foot-long one).
We’ll show you how to build a 4x4-foot raised bed, which is a good beginner template because you can walk around the entire garden easily.
Two 2x6-inch cedar boards, which don’t rot with age. They come in 8-foot lengths, which is perfect for 4x4-foot beds. You’ll need to cut each plank in half, so that it is 4-feet long. Or, you can have a home improvement/lumber store make the cuts. Many places will do it for free.
3-foot length of a 1x1-inch pine stake; you’ll need to cut it into four pieces, which you’ll add to the corners of the frame for bracing.
- If cutting the planks yourself: Hand saw, tape measure
- Drill/driver and bits, screwdriver
Make the Bed Sides
- If your two 8-foot long boards were not pre-cut at the lumber store, mark off the half way point and cut each plank in half for a 4 ft x 4 foot bed. Then you’ll have four planks.
- You’ll screw the planks together using decking screws. Two holes at the end of each plank is sufficient. Drill pilot holes using a drill bit slightly thinner than the screws themselves. One end of each plank will overlap the end of the next and screw directly into it, so position your pilot holes correspondingly.
- If you’d like extra bracing and a sturdier frame, cut your pine stake into four pieces and use them to nail the boards at the corners for bracing.
Assemble the Raised Bed
With all the wood cut to size and the holes drilled, we’re ready to begin putting together the bed.
- Lay down the beds. The walls need to be laid out so that each plank overlaps the next with the pilot holes located at the overlapping end.
- Screw the walls together with long screws so that each wall is probably secured to the next.
We want a snug, close fit.
Fill the Bed
- Fill your bed with a nutrient-rich compost mix (homemade or commercially-produced).
- Then, top the compost with enriched top soil especially formulated for vegetable gardening. It has a fine texture to allow for immediate sowing and planting.
- Fill your beds all the way up! The soil will settle, especially with watering. As it settles, you can always top off with compost.
That’s it! Your bed is ready for seeds and plants.
Watch our friend Ben share more tips and demonstrate how to build this raised bed in this video:
Filling a Raised Bed
The most important part of any garden is the soil, and the more organic matter it contains, the better. Soil microbes are fed, oxygen and water readily reach roots, and plants thrive as a result. Here is the balance to aim for:
- 40% compost: Compost is packed with nutrients for plants. While you can compost at home, it can also be purchased in bags from your local garden center. Aged manure can also be used, but you can NOT put fresh manure directly in your garden. Learn more about manure.
- 40% topsoil: In terms of topsoil, we’re not talking about “potting soil,” as it’s too fluffy for raised beds. You’ll also find bagged topsoil at a garden center or local farm supply or lumber store.
- 20% aeration: In terms of aeration, a lot of bagged soil mixes already contain some perlite, pumice, or rice hulls. If not, you need to add something for drainage. Lava rock is also a good aerator for drainage.
If you are filling a lot of raised beds, we’d recommend that you look into a local landscape company for build soil and compost mixes which should be cheaper. But if you’re just filling up a small bed, bagged is the way to go.
There are two approaches to filling your bed:
- Some folks pour in the compost (or composted manure) first and then add the topsoil (as shown in the video above).
- Other folks add the ingredients in layers like lasagna, mixing as they go.
Do whatever is easier for you!
At the end of the growing season, in fall or winter, top off your raised beds with more compost. As it get worked into the soil, it will improve the fertility and will be all set for planting by spring.
Raised Garden Bed Soil Mix
Here’s the recipe we’ve developed in the last decade that works best for our garden beds.
For one 4 x 4-foot raised bed. (Multiply amounts to fill larger beds.)
- 4-cubic-feet of top soil
- 3-cubic-feet of coconut coir (Note: Traditionally, peat moss has been used as a component of garden soil, but given that it is not a sustainable material, we recommend using coconut coir instead.)
- 2 to 3-cubic feet of compost or composted manure
- 2-inch layer of shredded leaves or grass clippings.
If you use grass clippings, make sure they are not from a lawn that has been sprayed with herbicides or been fertilized with a food that contains granular herbicides to kill weeds. Both persist and will kill plants up to three years after the initial application.
Mix all materials with a hoe or cultivator and water well. Be sure to mulch well with organic matter such as more leaves or clippings or straw.
In the first year, you probably won’t need much added plant fertilizer or go light on the fertilizer. But in following years, as your food crops suck up all the nutrients, your soil will need some amending with a balanced, slow-release fertilizer (or more compost). See How and When to Fertilize Your Garden.
Once you plant, you’ll want to top off your bed with some mulch (leaves, straw, pine needles, or more compost) to retain moisture and suppress weeds. Read all about mulching here.
What to Plant in Raised Beds
If you’re a beginner gardener, we’d advise that you start with one raised bed and try your hand at growing some of your favorite vegetables. Utlimately, four or five raised beds grouped together makes a good-sized garden.
What you grow is only limited by the depth of your soil—which is the depth of your raised bed plus the depth of the soil you dug and loosened below ground.
What grows well in 6” soil depth:
Lettuce, salad greens, spinach, onions, leeks, radishes, strawberries, basil, chives, cilantro, dill, mint, oregano, parsley, thyme, marigolds, and other annual flowers
What grows well in 12” soil depth:
Beans, beets, broccoli, Brussels sprouts, cabbage, cantaloupe, carrots, cauliflower, collards, cucumbers, garlic, kale, summer squash, Swiss chard, turnips, lavender, rosemary, sage, borage, calendula, cosmos, lantana, nasturtiums, snapdragons, sweet alyssum (plus everything in the 6” list)
What grows well in 18” soil depth:
Eggplant, okra, peppers, pumpkins sweet potatoes, tomatoes, watermelon, and winter squash (plus everything in the 6” and 12” lists)
For ideas, we have some sample raised bed vegetable garden plans—with plant lists!
Also, note that many vegetables grow best from seed, but some plants do better as young starter plants (especially tomatoes and peppers). See how to start seeds or plants.
Planning a 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 even 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.
Square-foot gardening in a raised bed. Photo by Oregon State University/Wikimedia Commons.
Whichever 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 also a companion planting selector so you pair or group crops that thrive together.
Test out our Garden Planner with a free 7-day trial—plenty of time to play around and plan your first garden!
- Check out our Plant Growing Guides for advice on growing all of the most popular vegetables, fruit, herbs, and flowers.
- See the Planting Calendar to find out the best days to plant all your common vegetables, herbs, and fruit.
Have you ever thought about building your own raised garden bed? Or do you have one already? Tell us about it below!