How I’m Going To Build A Simple Tall Raised Garden Bed

Tall raised garden bed

First of all, why would one build a raised garden bed at all?

The most likely answer is for the sake of bending over and your back.

Other reasons include the comparative ease to amend and control the garden soil, and the potential to construct / attach a sort of green house cover in order to start the growing season earlier in the Spring.

All New Square Foot Gardening II

A DIY GUIDE TO RAISED BED GARDENING

I’ve built more than one raised garden bed in my life ( ;) ) however I’m about to build a few more. So I’m revisiting different ways to build them and formulating a plan…

 

Raised Garden Bed Building Materials

I suspect that the most common material used to build a raised garden bed is wood, though surely others have used building materials such as cinder blocks or even poured concrete (permanent!).

Here’s an article about building a garden bed framed with concrete.

 
Pressure Treated Lumber
Pressure Treated (PT) lumber used to contain arsenic (CCA), although has not been used since 2003.

Today’s modern method of pressure treating wood utilizes a process that forces tiny microscopic particles of copper into the wood itself: Micronized Copper Quaternary (MCQ). The leaching of chemicals out of MCQ is practically non-existent and using the treated lumber for a vegetable garden bed is considered safe because the chemicals do not leach out into the soil. This according to the National Gardening Association and similar statements and studies by Texas A&M Agricultural Extension Service and others.

I will be using today’s pressure treated lumber for my raised garden beds.

Screws
I will be using Star head screws designed for building an outside deck.

Why? Because they’re purpose-built to withstand the outdoors, and the Star head is far superior than a ‘Philips’ head screw (which can strip out if abused). Knowing that years later I will be able to easily remove the old Star screws without them stripping is reassuring.

Important: Use wood screws designed for use with pressure treated lumber. Otherwise they will corrode. An example would be commonly available Deck Mate Star-head screws that have a lifetime polymer coating.

I plan to use 4″ length screws which will bite 2.5″ into the adjoining 2-by boards.

Garden Bed Lumber size
I will be using 2×12 lumber in 12 foot lengths to build a frame 4 feet wide by 12 feet long.

I will be stacking two levels so the overall raised garden bed will be about 2 feet high.

Screen mesh for bottom
I will be using a screen mesh material (1/2″ mesh x 4′ wide roll of hardware cloth with galvanized finish) to attach to the bottom of the garden bed. This will prohibit underground burrowing creatures from stealing my carrots and such – just in case ;)

 

Building Methods

Slapping together four pieces of lumber to build a simple frame isn’t rocket science. However I’ll point out a few thoughts…

Leveling
If you’re concerned about appearances you should consider leveling the ground itself first. Depending on your land, it may be a bit challenging to get it perfect. In that case I suggest shimming where necessary while using an ordinary level for guidance.

Joining 2 stacked frames for a taller garden bed
There will essentially be two frames, one stacked on top of the other for double height. In order to secure the two sections and to prevent uneven warping of the two sections over time, this is what I’ll do…

With one frame set on top of the other I will join them together with a board fastened along the inside of each of the four adjoining seams. I will use a pressure treated 1×6 along the length of the inside seams (overlapping half above and half beneath) and screw it all together. I’m using 1×6 (instead of something a bit smaller) because I’ll be using 2×12 lumber for the top and bottom framed sections.

Prevent bowing of the wood after filled with dirt
It’s possible that the sides could bow out somewhat over time due to the weight of the soil pressing outwards. This may be especially true with a long run (I’m doing 12 feet).

To help prevent this I’m going to strap (screw down) a 4 foot length of a ripped 2×4 across the top of the garden bed width at it’s center. This should hold the middle together without it bowing outwards.

Another option may be to screw in a joist hanger opposite each other and set in (and fasten) a 2-by across the width, flush with the top.

Still another possibility is to drive stakes into the ground along the edge of the walls and screw them to the lumber. Doing so on the inside will hide the stakes.

Garden Bed Orientation

I’m going to align the length of my raised garden beds North-South. The planted rows will then have advantage of the morning and afternoon sun as well as a better spread of sun as it passes over from side to side. I will also plant my taller plants on the north side of the garden beds.

 
So that’s my plan…

22 Comments

  1. I’ve done several raised bed boxes, they are very handy.! What I used was untreated 20 foot 2×12 cut down to 2 -6 footers and 2 4 footers and assembled them making 6×4 beds with paths in between. I did coat the inside of the bed boxes with linseed oil and to outsides with Thompson’s Water Seal. Then filled with a soil mix. Every year the get soil added to them supplemented and added to with compost and many other things.

    Crops and results vary from year to year. This years experimental crop is 7 or 8 types of Garlic.

    1. ” I did coat the inside of the bed boxes with linseed oil and to outsides with Thompson’s Water Seal. ”
      Should read
      I did coat the inside of the bed boxes with linseed oil and the outsides with Thompson’s Water Seal.

    2. Forgot another thing.
      I also use 55 Gal barrels gotten for free from the local (small town) Water treatment plant. Just have to wash the residual water treating flocking polymer out.. I cut them in half or a 2/3rd 1/3rd portions and make planters or wicking barrels. I tried mineral lick tubs but they don’t hold up as long in the Sun compared to the barrels. The barrels work for mini crops, experiments or herbs. I did some (Fastigiata Pin Striped Peanuts – Baker Creek) peanuts in one last year for a test here in western IA. they did quite nice.

  2. Ken the big thing I find is with that hardware cloth anti vole defense is how deep your soil is needed for your plants. I am unsure if say Tomatoes would prosper in only 24 inches of soil. Not much root action beyond the hardware cloth from what I could tell. My concrete block raised beds are 32 inches deep and I have had good tomatoes.

    That depth did limit my sweet potatoes a fair bit. Thus my hardware cloth bottomed slatted boxes for taters this year.

  3. Oh I forgot the reason I thought that hardware cloth did limit the root depth was when I dug up my sweet potatoes. I burrowed down to the hardware cloth to check durability in soil and how deep the sweet potatoes rooted and made taters. Very few roots seen past hardware cloth.

    BUT No Vole Damage for two tears so far :-)

  4. 6×6 landscape timbers spiked together

    Hollow tile filled with dry sackcrete then watered

    Stacked log pieces

    Stone walls

    Batch samples from a concrete plant

  5. we have a number of raised beds, built from untreated lumber, about seventeen yrs ago. Where the ends of the “planks” butted up against each other, roof truss connector plates were pounded on.to further hold them tight (in addition to screws as above). I think the roof truss connector plates were instrumental in keeping the beds firm/straight, even after all these yrs.

    1. Its interesting lumber lasts so long over there, at my place a treated board laying on the ground will be rotten in a year

      1. Nailbanger
        we have been truly shocked, at how long it is lasting. (keep in mind, severe winters/deep snow/high winds/lots of rain/lots of watering during growing. We figured a few yrs, tops. Last yr some started “wibbling” a bit, bending a bit, but frankly still holding well. Figure the bottom edges likely rotten, but those connector plates are tough and holding it all together (can see places where the screws have come out)

  6. We built 4 raised beds for veggies and used treated 2×6 lumber, built 3 high . I put a 2×4 flat on the top edge to have a 3 1/2 ” seat to sit on that was somewhat comfortable. We made them 3 foot wide to reach the center without too much effort.I also used 1/2 x1/2 hardware cloth to keep out the underground varmints .

  7. Not really a raised garden, but more like a border, strips of drywall are not only cheap but beneficial to the soil as it breaks down.

  8. We have a lot of raised beds. Built from everything we could salvage, concrete blocks, ATV tires, cedar 1 by 12’s. Some made from cedar logs, 10″ diameter, spiked together with re-bar, these are the best.
    My gardens are quite big, 2 acres, We only use the raised bed around the house. I row crop everything else. Beets, beans, carrots cabbage, corn, ect ect, are all machine planted, and cultivated. Small scale equipment.
    Although the jury is still out, by far the coolest raised beds are called “Hugelkultur” beds, buried soft and hard woods. I used cottonwood and apple and pear wood, along with willow chippings and straw, and fresh horse manure. This is my second year, the wood ain’t rotten enough yet, so I’m probably just gonna cover crop with vetch and red clover again. Building up the soil.
    Never used treated lumber or RR ties, was afraid of the chemicals. Mostly just raw cement and wood. The tires, well, we just use them for borders to stop plants like mint or horseradish from spreading and going nutso.

  9. In years past, I have been using whiskey or wine barrels sitting on the ground and filled with a mix of poor soil on the bottom with new potting soil on the top. There is also a generous amount of cow manure mixed in with the soil mix. The barrels. are drilled on the bottom in multiple locations for good drainage.

    In the front yard, I have created a few circles within the parking strip which is simply lawn border edging material held in place with wooden stakes pounded into the soil and acts as a margin to hit with the weed whacker. I fill the circles with the same fertile mix of amended local soil. Right now, I have daffodils blooming in the circles. These circles are where I grew squash last spring and summer.

    Planting depth in the barrels are around or less than 2 feet. This was plenty for the variety of tomatoes we grew last year which was a borderline cherry tomato. ( unsure of the variety – the smaller tomato plants seem to do better within a container.) We dedicate one container for each vegetable because some plants are very aggressive and will push out other plants. My wife likes to plant flowers in the barrels as well.

  10. My husband made me a 20×30 raised bed garden about 10 years ago. We thought about treated lumber but when we bought the materials the lumber guy said regular would last our lifetime. (wise*&$%) Anyway the beds are all my height. For the floor and because we are on the saddle of a mountain slightly slanting downward, he put in 8×4 cement cap stones with sand underneath to level it. Then he put treated 4×4 post underneath the beds as we found our pocket gophers somehow were able to climb up the sides of posts put at the ends and get in the boxes. This way they can’t. Our beds are about 18″ deep made with a shovel of our ugly dirt and then a lot of shovels of peat moss and sterilized cow manure. We don’t use local manure because of all the grubs in the manure. Then the whole thing is enclosed with chicken wire with a structure that can be enclosed as a greenhouse if we wanted. But we haven’t done that. It works well as is. The roof is about 8 feet tall. We also have some railroad ties that function as steps going downhill. The beds are 4×4 with a couple 4×8. We also have licktubs up on blocks. These are tubs you can buy from ranchers that they get for their cows. They sell them for about $2.50 each and they are about 2 feet wide and probably 2 ft long. These are great for the perimeter of the garden. We have grapes and blackberries in some. The garden is arranged in 4 rows and he even put in a 8×8 corn patch in the ground with hardware cloth 18 inches deep. And now a raspberry patch with the same hardware cloth. Every year we turn the soil over and add peat and manure. When we plant we usually have enough to feed the whole neighborhood. Oh he also put in a sprinkler system or I would be down there 1/2 day watering. We also get bad winds March-June so we put up shade cloth on the fence. This is our second garden. The first was raised beds in the ground with hardware cloth but over the years the hardware cloth seemed to move just enough to let the critters in.
    Wish I could include a pix.

  11. I have two 4′ x 8′ raised bed gardens, constructed using Cedar Logs harvested on my property. (More Cedar Trees than ever needed). The frame uses logs between 6 and 10 inch diameters, 4′ and 8′ length. I used a 1/2 in boring bit to drill holes, and pounded in sections of 1/2″ rebar to hold everything together. Also used semi-rotten hardwood pieces (NOT CEDAR), as filler in the lower portion, (the “Hugelkultur” method). Assembling the beds by myself was a breeze, using my home made “Thumb” attachment on the backhoe of my Kubota tractor, to place the logs. Only minor drawback with Huglekultur is that the top dirt settles some, requiring additional filler every couple of years.
    One of the gardens is strictly for Herbs, the other for various root vegetables, along with lettuce, Spinach, etc.
    I use containers for my Pepper plants.
    A strange coincidence – just yesterday I skidded out 4 more Cedar Logs to use as a border around my small regular ground level garden. Hopefully the sides will be gradually raised, as I acquire more compost, etc.
    There is absolutely NO decent topsoil in this part of the Ozarks, so it must be made. I use sifted clay mixed with
    rabbit pellets, shredded leaves, and other compost to make dirt. Problem is it seems to take forever.

  12. Consider using a tractor tire. Most tractor tire stores are trying to get rid of them and would gladly give them to you. If you have the strength of a tractor, you can turn them inside out for a neat textured look. They are the right height for sitting on and weeding. They gather heat with the black tire color and have enough mass to minimize evaporation. If you stack two together, and bolt them together, they are the right height for a wheel chair. I have not tried tractor tread yet for a boarder wall of an irregular shaped garden.

  13. We will be making two raised beds in the fall. Not now because I don’t want to push hubby into another problem, We will use 1 X 6 or 1 x 8 wood for the sides of the box and plywood for the bottom. They will be 2 X 8 foot in total size. We will sit the front up on two stacks of three milk crates and the backs of the boxes will be bracketed to a 2 X 4 secured to the fence. Three milk crates is a good height for me, saves my back. These follow the square foot gardening principles and work very well, even for beets and most carrots, Don’t have to worry about anything but the neighborhood cats, which I think I can foil with some chicken wire. Tomatoes and vining crops I will put in 5 gallon buckets and hang from the porch roof braces. Hook it all up the the automatic sprinkler system another back saving device.

  14. I have been doing Raised Beds for many of years, for a couple of reasons;
    1. When I purchased the land I’m currently on I forgot to indicate I wanted “Soil” with the pile of rocks I bought.
    2. Rodents don’t seem to climb the 2’ high beds I have
    3. I’m sick and tired of crawling around on the ground; the 2’ high is GREAT.
    4. I’m amending the ‘soil’ I actually plant into, not a HUGE area and just putting rows in.
    5. Square foot Gardening is a LOT easier on the water bill, in the desert here.

    So, what do I use you ask? For the ‘main’ 4’X8’ beds (6 beds now, 2 more coming this year) I have used concrete forms, those “Simmons” forms that are steel frame with a layer of marine plywood made for forming up Concrete Walls. These panels are 2’X4’ so I simply lay them on the side and fasten with the normal hardware used in form-work.
    Other containers are 55-gallon barrels that are cut in 1/2, I place these on top of Pallets to raise them up more, probably 3’ to the top, perfect height. Don’t forget the holes in the bottom
    I also had a source for a lot of Milk Creates, so I line these with Landscape Fabric and fill with good soil, these make GREAT planters for Peppers and the likes, FYI Cherry Tomatoes thrive in these. Theses also go up on Pallets for 3’ to the top.

    One thing I have noticed is I use a LOT less water with the raised beds that the old “Garden Patch”. AND weeding is a piece of cake, I have zero problem with rodents aka Rabbits, Squirrels, and Chipmunks, seems the 2-3 foot high is just right for Freezer Meat.

    1. NRP
      You are referring to our lawn ornaments …. only required when the phooo hits the fan. lol

  15. I would never use pressure treated lumber! You are trusting them when they say “NO HARM”.

    I built four 4x8x2 foot beds three years ago out of untreated 2×12’s and have had no issues. (Other than they are buried right now by snow!)

    These four beds feed my wife and I more than you could imagine. We end up giving away food all summer.

  16. I built 3 raised beds two years ago. Each are 3’x9′
    I couldn’t be happier. I think they are about 18″ or so high.
    I just turn the dirt at the beginning and end of the gardening season.
    I put my end of season compost in each bed in the fall and turn it.
    The snow melts down into the beds, and come spring, I have great dirt.
    My peppers and tomatoes have thicker walls and taste wonderful.
    This year – I plan on planting more “less” acid loving plants. Beans and peas
    would be good. I would like to try corn as well. I have enough tomatoes and salsa
    to last me (I just prep for me now) two or three seasons… That said – By rotating my
    crops – I can jar up the beans, or dry them, or what have you to preserve them.
    I have an all American pressure canner…. I’m good to go with all my harvest preservation tools.
    I also bought Tattler re-usable canning lids. What a great item to compliment mason jars!
    I have people asking me all the time to help them with their gardens and canning supplies.
    I tell them that composting is an important part of gardening.
    For those that are interested; do a bit of research on “Bokashi” composting.
    Ya’ll might like what you learn. :)
    Good day!
    Keep on… keeping on!
    ~YO3

  17. We have 5 raised beds, all 4 feet high and 36 feet long. We have no top soil on our place, just shale with a thin layer of organic matter. Anyway there is no way to grow vegetables (or flowers).

    A few issues we have had with this including soil pressing against the walls.
    > The 4×4 poles placed in the ground need to be on the outside the boards making the walls. Only one of the beds is pushing outward and its the one that my husband accidentally placed the poles on the inside.
    > Sometimes the soil can be too rich and the plants can be all leaves and no fruit. Moderate your organic matter.
    > My husband put stabilizer boards across the top of the bed to stabilize the bed walls.
    > Sometimes the soil can be too rich and the plants can be all leaves and no fruit. Moderate your organic matter.
    > Don’t put your plants too close together. We found that the plants grew large and ended up crowding each other. This shaded out some of the fruit and also spread disease.

    We are very happy with our beds and they supply a lot of food for us each season. Good luck!

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