Bermuda grass is my nemesis.
It has worked it’s way into my vegetable garden despite all my attempts to stop it. After our Summer garden was finished, and it was time to start planning for the Fall, we decided to go with the raised garden bed method. All we had to do was find the best material for raised garden boxes.
Benefits of using Raised Garden Boxes
- Less weeds (especially from weeds that grow using rhizozomes — like that pesky Bermuda)
- Less compaction – it’s amazing what happens when you don’t step on the soil.
- Less tilling – While it can be expensive to initially fill raised garden boxes with soil, it can last year after year and make your life a whole lot easier.
- You can plant closer together instead of in rows, often called square foot gardening. This is because the nutrient density of the soil composition can handle the close proximity of planting.
Choosing a material for your Raised Garden Boxes
This decision was a tough one. There are a lot of options to choose from when creating your raised garden boxes. Here are the best materials for raised garden boxes.
Cinderblock
PROS | Cinderblock is cheap and available at any local hardware store. Very durable and will last many years.
CONS | It’s heavy to lift and can hold heat. This can be a good thing in a winter garden, but for a summer garden, it can really raise the temperature of your plants.
Rock
PROS | The material can be free depending on where you obtain it. It also gives your raised garden boxes a very rustic & cottage-look.
CONS | Can be heavy to lift and work with. Unless you fill the space between each rock with cement, weed and grass will make their way in.
Concrete
PROS | Makes a very clean look and can last the longest of all structures.
CONS | Very expensive, and hard for a DIYer to do on their own.
Galvanized Metal or Stock Tanks
PROS | Gives your garden a cool industrial look and is the quickest to set up of all raised garden box materials.
CONS | Can be very expensive, and although it’s been galvanized to protect against rust, this doesn’t make it completely protected, and these can rust over time.
Steel
PROS | Provides an industrial look & takes up less space.
CONS | The cost can be high & steel will definitely rust and weather. This isn’t ideal for growing edible vegetables.
Wood
PROS | Very cost-effective and easy to install.
CONS | Wood won’t last forever, but it can last a good 10 years before it starts to rot.
Wood options for Raised Garden Boxes
NOTE: When choosing wood, BE SURE to use untreated wood. In 2003, the EPA banned the sale of lumber treated with chromated copper arsenate (CCA) for residential use. Two compounds, alkaline copper quat (ACQ) and copper azole (CA-B), have now replaced CCA wood in the residential market. Both contain copper and a fungicide but no arsenic. The copper keeps insects at bay, and the fungicide prevents soil fungus from attacking the wood. In ACQ, the fungicide is quat, which is also used in swimming-pool chemicals and as a disinfectant. The other compound, CA-B, uses copper and tebuconazole, a fungicide used on food crops. According to Miles McEvoy, who works in organic certification with the Washington State Department of Agriculture, no pressure-treated wood is allowed in soils used to grow organic food. If you want to meet this high standard, choose a different material. (source)
(Each of the following options are typically untreated wood — though it wouldn’t hurt to double-check when purchasing)
Redwood or Black Locust – Definitely the best option for raised garden boxes in terms of longevity because they are naturally rot-resistant and have been known to last up to 20 years. The con though is what you’d imagine — they are expensive! One of these types of wood will run you 3-4 times the cost of a cheaper wood.
Cedar – Another rot-resistant wood, cedar can last 10-15 years and looks gorgeous. The con is that it’s also expensive, around 2-3 times the cost of cheaper wood.
Douglas Fir – Douglas Fir can last 5-7 years, and is the cheapest of the types of wood used for raised garden boxes. It’s also the most affordable option!
Which type of wood did we choose for our raised garden boxes?
We decided to go with Douglas Fir. Wood, in my opinion, is the best material for raised garden boxes. I was willing to spend more money on Cedar or Redwood, but in the end, I knew that I’d probably change my mind in the next 5-7 years on where I wanted my raised garden boxes, and there’s always the possibility that we may move from this home.
We built (1) 10×3 and (2) 16×3 boxes, all 14 inches tall. We purchased wood that was 2 inches in thickness as well. The total cost for our wood was $220.
Stay tuned for more posts on how we built our raised garden boxes and what type of soil we filled them with!Â
Hiya
In Spain, looking to do some raised beds.
I see lots of timber that is : Autoclave treated, I had to google it 🙂 see Appendix
https://www.bauhaus.es/vigas-y-traviesas-para-terrazas/traviesa-de-madera/p/22373380
What do you think in terms of using this kind of wood in raised beds?
Appendix
“Autoclave-treated wood is typically used for building timber, door frames, window frames, shutters, and other wooden materials. The process of using an autoclave for timber impregnation is fairly simple. The first phase of the process is to use a vacuum to remove the air from the pieces of wood, Next, non-harmful preservatives that are water-based or composed of other safe substances are then injected into the wood. This is what gives the wood the ability to last longer and resist the harm caused by bugs, rain, and other environmental elements. The last phase of the process involves drying up the wood so it can be processed for shipping.”
Hi Ian-
Have not used this before, so I cannot say how reliable it is. However, if there are no harmful chemicals and it can stand up to the elements then it would be worth trying.
If you use it let us know how it goes.
Thank you -Bobbi (DaNelle’s Assistant)
Hi There ,
I have small back yard in which I have few small fruit trees , I used to plan vegetables in between the space of the trees , but now gophers are creating lot of trouble . hence Iam planning to build a raised bed around the trees , leaving a round/square shape space around the three( I will covering with wood same level as veggie raised bed ) here are few questions , appreciate your answers
1. Iam in CA , here I found Douglas wood is the only option .., this veggies bed starts with in few feet from my basement doe it attract any termite to by basement ..?
2.To increase the life of teh bed is there any safe coating we can apply ..?
any other Tips/ suggestions/precautions for my above project as my space is limited ..
3, which is teg best material to use to keep gophers and weeds out ..
4. what is the coast effective soil I can purchase to fill the bed .. can I use the dirt in my back yard to mix with purchased potting soil ..
Appreciate your Answers
Hello-
DaNelle decided to leave it unfinished, but some people seal it with beeswax.
For soil here is DaNelle’s suggestion: https://www.weedemandreap.com/best-soil-combination-raised-garden-boxes/
These articles can help you with your other questions:
https://www.sfgate.com/homeandgarden/goldengategardener/article/Gophers-can-be-discouraged-by-these-plants-3588677.php
https://homeguides.sfgate.com/kill-garden-weeds-poison-86598.html
https://www.sfgate.com/homeandgarden/article/Can-you-kill-termites-with-kindness-3297926.php
Thank you -Bobbi (DaNelle’s Assistant)
Great post, DaNelle. Thank you for sharing your knowledge and experience! It looks like this was posted back in 2014. I was wondering if you could speak to how the fir held up over the past 6 years? I am thinking similar to you, using fir for my initial raised bed construction since I may move/upgrade/all sorts of changes can happen in 5-6 years that the wood will last! Just hoping it lasts around 5 years so I do get some use out of it.
Thanks!
Hi Sarah-
The boxes held up fine, but DaNelle took them out last year because she was changing things up for her garden.
Thank you -Bobbi (DaNelle’s Assistant)
thanks for the reply, glad to hear!
I was wondering, and didn’t see here, what are your thoughts to re-purpose a kiddie pool? Hubby says it isn’t a good idea because of the material, but I can’t find anything anywhere where it isn’t safe. Your thoughts are greatly appreciated.
Hi Tammie-
It depends on the plastic the pool is made from. This article gives a breakdown of which plastic are safer to use for gardening. https://www.epicgardening.com/which-plastics-are-safe-for-gardening/
Thank you -Bobbi (DaNelle’s Assistant)
Hi! Can you say more about why steel is not the best choice? I’m looking at repurposing corrugated roofing sheets from my old garage. Is this going to be toxic in some way?
Hi Lex-
It depends on what type of steel it is, if it is coated, what the acidity of the soil and water you are using are, and what your price range is. Steel can be used if you know what steel you are working with and what it will come into contact with.
These two articles talk about when acidity becomes a problem and the difference between stainless and cheaper steels.
https://www.epicgardening.com/galvanized-steel-garden-beds-safe/
https://www.scientificamerican.com/article/why-doesnt-stainless-stee/
Best of luck with your garden boxes!
Thank you -Bobbi (DaNelle’s Assistant)
Thanks for writing about this. I recently visited different shops for the selection of wood and got confused. But, your article has cleared up my mind, and now I have decided to go with the third type of wood that is Douglas Fir. Plus, I found some amazing tools to do the chore. Here, I have some questions, can you please tell do I need to fill it up with any specific kind of soil? If so, then which soil type would be appropriate?
Hello-
Here is DaNelle’s suggestion for soil to use: https://www.weedemandreap.com/best-soil-combination-raised-garden-boxes/
Thank you -Bobbi (DaNelle’s Assistant)
Fyi you can still get pressure treated lumber. We just bought some.
Pressure treated lumber has chemicals in it…you don’t want to use that for vegetable planters.
Cinder blocks & cement are both highly toxic… I would not recommend anywhere around your food. These are also very acidic, so as soon as a higher pH (alkaline) comes into contact with these surfaces, they begin leaching.
For the people asking if vinyl is okay… the answer is a firm “no”. As soon as vinyl starts to heat up, it leaches out plastic toxins.
Also, treating wood with stain, paint, or nearly anything else is asking for trouble. It will make its way into your soil and is carcinogenic. This is your food, keep it as chemical-free as possible.
Otherwise, the way the author built hers is already perfect– just stick with those instructions. I shake my head how people get themselves into trouble.
What about food grade mineral oil for treating the wood as a way of slowing the deterioration? My wife and I have a butcher block island which we occasionally refinish with a light sanding, cleaning, and an application of mineral oil.
Does keeping weeds under control in wooden beds is taff??
Hi Andere-
The raised garden beds do help control weeds.
Thank you -Bobbi (DaNelle’s Assistant)
I bought larch wood for my raised beds from the RI sawmill, where Joe cut the planks a full 2″ thick for me and delivered the planks to my house. Wikipedia says this about Larch: “Larch wood is valued for its tough, waterproof and durable qualities. Top quality knot-free timber is in great demand for building yachts and other small boats, for exterior cladding of buildings, and interior paneling. The timber is resistant to rot when in contact with the ground, and is suitable for use as posts and in fencing.”
It was MUCH cheaper than cedar or even pine or fir planks available at local lumber yards, and it is holding up excellently after three years. I expect it to last a good 10 years or more. My beds are 9′ long, 4′ feet wide, and 12″ high (using two 6″ planks stacked stacked on top of one another for economy, since 12″ planks are so much more expensive). No bending or cracking or any other problems of any sort. I recommend them highly!!
Hello, Susan!
By RI do you mean Rhode Island or is that the name/initials for a lumber mill in Arizona, where the author of this blog is located? Thank you for a reply if you see this!
Andy G.
Chandler, AZ
Hi! Any thoughts on untreated pine as an alternative to fir? Where I’m located (Texas) pine is the most common/inexpensive lumber option so I’m wondering if it’s our version of the fir, or if you’d still prefer fir over it. Thanks!
Hi Sunnie-
Yes, you can use untreated pine to make your garden boxes, especially if it is a cheaper and more readily available product. Just know that it may not last as long as some of the other options. When using pine some people treat it with linseed oil (made from natural flax seed) to make it more water resistance. However, this doesn’t protect it from sunlight damage and linseed oil is flammable and takes a long time to dry.
If you choose to use linseed oil just make sure it is pure raw linseed oil and not a mixture with solvents and heavy metals, sometimes called boiled linseed oil.
I hope that helps! Good luck with your garden boxes!
Thank you -Bobbi (DaNelle’s Assistant)
My husband and I are planning on doing raised beds in our backyard and I found your blog on Pinterest! Just had to say I LOVE the name of your site! My husband and I both had a good chuckle 🙂
I like that you pointed out that cinderblock is affordable and can be bought at any local store while being durable as well. With that in mind, I will choose this for my garden since I am on a limited budget due to spending almost all of my savings to buy this house. I just chose this property because one of the things it attracted me is the part wherein I can start a garden which I badly want to have ever since I was a teen.
What store do you recommend to get your wood and all the supplies for the garden?
Hi Megan-
You can go to DaNelle’s Resources page to get some of the items:
https://www.weedemandreap.com/resources/
You can find most of the other items at larger stores such as Home Depot or Lowe’s.
Thank you -Bobbi (DaNelle’s Assistant)
What would be the best natural organic soil to put in the raised garden box’s?
Should I buy truck loads of triple mix?
Hi Ryan-
This is what DaNelle suggests for soil: https://www.weedemandreap.com/best-soil-combination-raised-garden-boxes/
Thank you -Bobbi (DaNelle’s Assistant)
It got me when you said that cedar will be able to last 10-15 years while ensuring you that it will not rot. I guess I will be choosing this for the garden boxes that we want to put in our backyard. It’s for the area that we plan to turn into a garden since our backyard is quite wide, and it looks boring to have nothing to see there.
I used wood, left some untreated and painted the rest with polyurethane, taking special care to soak the ends of the wood. Both rotted out in 2 years.
I guess, other than cost, using 2 inch thick wood would always be better than 1 inch thick right?
Hi Herm-
Yes, it would be. Makes them sturdier. Thanks -Bobbi (DaNelle’s Assistant)
Thank you for pointing out that wood boxes are very cost efficient and easy to install. My husband is wanting to start a garden with our daughter this year. I think we should look into buying some raised garden bed kits so they can have an amazing summer and we can make sure the plants are safe.
Ready to build my untreated cedar boxes do you recommend any screws to use to attach the corner pieces?
Thanks!
Hi Shawn-
This article has a link to wood screws DaNelle suggests. https://www.weedemandreap.com/build-raised-garden-boxes/
Good luck with your garden boxes! Thank you -Bobbi (DaNelle’s Assistant)
I’m looking to purchase 1 maybe 2 elevated garden boxes (untreated cedar) so I don’t have to bend over.
Any store suggestions?
Hi Aisha-
On DaNelle’s Resources Page under Gardening (about halfway down the page) is a link to Cedar Raised Garden Boxes from Amazon that could work for you. https://www.weedemandreap.com/resources/
You can also buy untreated cedar from Lowe’s or Home Depot, just be specific in what you ask for. Also, if you are lucky enough to have an actual mill in your area, go there and they can help you too. I hope that helps! Happy Gardening! Thank you -Bobbi (DaNelle’s Assistant)
I have a bunch of pressure treated materials to use for beds. Is there any product I can paint on them to prevent toxins from leeching into the soil?
Hi Paul-
I am not aware of anything you can use to paint onto the pressure treated wood that prevents leaching. However, if you do choose to use it anyway, here is some information and some tips (at the bottom of the page) to minimize (not eliminate) the risk of exposure to toxins from Penn State Extension. https://extension.psu.edu/environmental-soil-issues-garden-use-of-treated-lumber
I hope this helps. Best of luck and Happy and Safe Gardening! Thank you -Bobbi (DaNelle’s Assistant)
About 6 years ago, I built 2 boxes from cedar, but went with 1″ x 8″ boards, stacked 2 high. The boxes are each 14′ long and 4′ wide. The wood began to warp and split, so this year I am replacing them. I wanted cedar again, but in 2″ x 10″ (also going two board high). Purchasing 11 cedar board would have cost me $1,000. Instead I went with Douglas Fir at about 25% of the cost.
I am staining the outside and top surfaces (no direct dirt contact), and oiled the inside surfaces with teak oil. I used galvanized brackets at the top and bottom corners of the lower boards, forming a very solid base. The upper boards are connected to each other and the lower section with 4 interior corner posts, and a full height cross beam at the mid point, also secured with corner posts. All screws are from the inside. I lined the inside with black cloth weed block, and laid the old cedar like floor planks in the base. It can decompose into the soil. My boxes actually look remarkably similar to yours other than the stain.
These boxes will require substantially more soil to supplement what I removed from the old boxes. I fill them with a mix of roughly equal parts local soil (clay heavy), store bought garden soil, compost and peat moss.
I grow:
Tomatoes
Garlic
Onions
Peppers
Lettuce
Spinach
Carrots
Basil
Snow Peas
Green Beans
Productivity is good most years, but varies with weather and how much care I provide.
Considering steel beds. What about heat absorbtion? Is that a problem in hot and dry Colorado Springs? I don’t want to bake the roots.
I have heard you have to be careful when planting close to the edges in steel beds. Other than that, you’ll probably be fine. Just be sure to put these boxes on the east or northeast side of the house with some good afternoon shade.
I bought a raised bed kit from Lowes so it is like a plastic material. The grass went crazy so I bought some wood and made a large outlining barrier that now goes around my raised bed and some tomatoes that I have growing in pots. I laid a weed blocking sheet then put rocks on top of it to make a finished look and hopefully stop the grass from growing up like crazy. The wood I chose was treated. Do you think this is ok since it it on the outside of everything and the soil for the raised bed is not actually touching the treated wood? Or do I need to change it out?
I say keep it!
https://www.melbartholomew.com/
The originator and founder of Square Foot Gardening
My biggest question is what kind of material did you use on the inside? If you didn’t, what kind would you recommend? I’m building one for my wife, and I want it to be portable as well. I’ll post pictures when completed. But anyway, I need to figure out the best cloth that will breathe, not rot or degrade, that I can also line the bottom, to drain water and allow the bottom of the soil to aerate as well. Also, what kind of rub or stain is best for exterior of wood, plant safe? Thank you. I did not see anything after the wood you chose. Thank you
I’m wondering how your fit beds are holding up
Great! Still working and loving them!
Hello! We too chose wood! We got cedar which was more expensive but I was hoping it would last longer. But now I have a question….is there any ‘safe’ top coat that we can give it to protect the wood from the snow and elements? Is there a way to stop the pretty ‘white’ wood from turning dark and gross due to the elements?
Any tips would be greatly appreciated! 🙂
Hi Zahra, I had the same question! I decided to leave it unfinished, but I hear a lot of people seal it with beeswax.
You can always use a UV coating on cedar, it is the sun that messes with color. Also don’t use anything that will hold moisture in wood, it will rot inside out.
Hello,
I’ve read somewhere before about lining the bottom of the boxes with cardboard boxes to help slow weed and grass growth up into the garden….did you line the bottoms of your boxes at all? I really want my garden to be organic, but I’m not sure how to get started. 🙂 Thanks for this post on box materials, it’s a great start for me!!
Yes, absolutely! I layer the bottom with cardboard!
What about the toxins present in cardboard, aren’t you worried about contamination?
I think it’s minimal:)
Thank you for the information!! https://www.lovesthefind.com/
HI I thought I posted but don’t see it so will try again. I was curious about using aluminum L brackets in a raised bed or planter box you plant to grow edibles in. I got hubby to agree to build me some cedar boxes but had no idea he was going to make some aluminum l brackets at work to use in the inside to hold them together. So I am curious should I be concerned about growing edibles in these or am I just worried for nothing. If you don’t know do you have any idea where I can find out more about it.
Thanks
jm
Hi Josie,
I wouldn’t be too concerned because it’s such a small amount, but in the future, I’d place those brackets on the outside:)
Hey, I have no “yard”, just concrete patios. Could I put the built boxes directly on my patio? Would it need to be lined, or a rock base for drainage? I’ve only ever seen boxes built on dirt, not concrete. I have a great sunny spot just next to my house, but the ground is a cement patio. Thanks!
Hi Gwen! If I were you, I’d create a wood bottom, then drill a few holes in it for drainage.
I’d like tp do this too, with the addition of heavy duty casters so I can move it back and forth? Later in the season the sun changes sides in the narrow area between the fence and the house…
Hi Nancy-
That sounds like a good plan and should work just fine as long as you have a box with a suitable bottom. Best of luck! Thank you -Bobbi (DaNelle’s Assistant)
Cement ground is great since you will have minimal concern from weeds, as long as you have good drainage (thick drainage rock layer, gravel, sand and drainage holes on sides of boxes); you may have to build higher than those on soil but that will also protect your neck, back, and knees.
I was wondering about using white vinyl fencing to make garden boxes? Is it safe?
Great question, Jennifer!
I always like to go with wood because I believe it’s safest, but vinyl might be okay as long as it doesn’t leach chemicals.
From a post on a facebook site regarding using concrete blocks for garden beds: ” I worked in the concrete block manufacturing business and had my own supply business for years. I also trained and studied at the National Concrete Masonry Association. Any time a product is used outside of it’s intended purpose there is a risk in it’s performance. The heavy metals and poisons, including many that are radioactive, scrubbed from coal fired plants are much more concentrated in fly ash than can be found anywhere else.
The process of creating cement locks these poisons into the blocks, but it is assumed that the blocks will be sealed and waterproofed. Without that waterproofing, which is also toxic, they will leech these materials into the soil and any plants in proximity. They should only be used for areas containing ornamental plantings only, and never for food crops.”
Wow Deb, thank you so much for sharing!!
Thank you! I was going to purchase blocks today! Any other ideas on how to use blocks safely
is it safe to line the inside of the garden box with tar paper? My husband says the box will last longer.
I look forward to seeing what you fill those boxes with. My raised beds are now three years old, and have (gasp!) BERMUDA grass growing up through them despite a double layer of thick planting fabric underneath the boxes. The boxes themselves are full of plants that produce very little fruits and veggies. Im thoroughly deflated with the time and money Ive put into these supposed “cant fail” square foot garden boxes.
I’ve heard that some people are unsuccessful with the square foot method, I’ll have give updates on my experience!
I had very good luck going to a small local sawmill and buying a whole pile of unsalable lumber for $50. I’ve probably made a dozen beds out of it and still have some left.
Wanting to put in 4 ft high raised beds. What do you suggest we use for the bottom 2/3rds for fill?
Look on Craigslist — you may be able to get crummy fill dirt for free. There’s always free dirt in my area from people doing landscaping.
It would depend on what kind of plants you are growing, and what your weather looks like year-round. I would be careful of getting just any soil, because there can be disease and rot and bugs from other plants or areas in the soil.
Your new beds look beautiful. Weather can be hard on them, though, and the cypress ones my DH built me only lasted a couple of years here in So. GA.
You may want to screw in L-brackets on the inside of the joints, to make them more stable. Also, for weatherproofing, you could “paint” them with melted beeswax or (not organic) paraffin wax, which would make them last longer.
As the old bumper sticker reads “Organic gardeners do it in raised beds”. 😉
Best wishes with yours.
Those look great! I tried the “heavily mulched with wood chips” method this year, and I think I didn’t use enough wood chips. Ha! Weeds kill me. At least I’ve been getting some exercise while I get the garden ready for fall.
Haha! Oh gosh, I hope I can keep the weeds under control!