There's a lot to consider when you want to build a raised garden bed. I feel it's important to nail down the reasons you want to build a raised garden bed in the first place, and focus on those factors most.
Do you prefer a higher bed height so you don't have to bend over when gardening? Are you interested in bringing in better soil because your native soil is less than stellar? Do you have so many predators that you need to build a fortress to protect your plants? The last one I have personal experience with, and will show what I did to combat said advisories.
The last two houses I have owned I had no choice but to build raised beds to garden in. I literally had no choice. It was either raised beds, or no garden. That being said, there were different reasons behind each garden.
My first raised bed garden I had to build because I lived in Eureka Springs Arkansas, and my house was on a rocky hill, no soil to speak of, and what soil was there consisted of 90% rocks. The slope my house was on was also around a 20% or so angle. It was less than ideal. So raised beds were built, and about 10 truck loads of soil were hand shoveled into the beds.
I did have other things to consider when building these beds. I wanted to maximize my space, use as little water as possible, and grow crops for as many months as I can.
Since my house was located in the woods, I had to cut back a lot of trees to get enough light to grow food. I was able to make it so the spot for the garden got light from about 9am until about 3pm. It took a lot of trimming, and I achieved this with a hand saw on a 30' extension pole. It was a huge pain in the ass.
Once I had the light covered, I focused on the design of the beds. I chose to put my beds in the only spot I could, not much of a choice to be honest. I just had to make it work. It was a slopping hill that was built up with a giant pile of rocks. It was unstable, but less of a slope than anywhere else on the property, and I was able to trim the trees back enough to get enough light to ensure good production.
(an aerial view of my raised garden beds)
When designing this garden I wanted to take into consideration the temperatures throughout the season. Since the highs in the summer could be mid-90's that would make it so cooler season crops like bok choy, lettuce, etc.. would not do well. But I wanted to grow those year round if possible, so I decided to do a multi-layer garden.
(an a-frame trellis with another trellis behind it)
In a multi-layer garden you can use one crop to shade another crop from the sun, thus creating a micro-climate. In that micro-climate it can be possible to grow crops that normally wouldn't do well it the dead of summer. A good example of this is an angle frame with metal wire across it that I grew melons on, below this frame I could plant bok choy, lettuce, broccoli, etc.. It worked very well.
(angled wire trellis with melons growing on it)
(bok choy growing under the melon trellis)
I also wanted to maximize my tomato production, and make sure that I could grow the most amount of maters as humanly possible, with the space I had available to me. After much deliberation I chose to create a tomato wall that ran down the entire west side of my garden. It was roughly 25' long and 8' tall, and it stair stepped with the rest of the garden. Because of how the light shined through the trees, and its' west side placement, the tomato wall did not block light from the rest of the garden. It actually helped to cut down some of the late afternoon sun, which made it so that I could grow other crops longer into the summer season.
(25' x 8' tomato wall with zucchini & squash in front of it)
Since I wanted to grow crops for as many months a year as possible, I decided to build in pvc receiver pipes into the garden bed frames. I could then build simple hoop house style frames out of pvc, and cover it in plastic. In doing this I had so much bok choy one Christmas that every person I knew got a basket full. All with one simple layer of plastic, I could now grow crops year round.
(PVC pipe built into the beds for hoop house frames)
When it came to watering this garden I wanted to cut down on the amount of work I had to put in, and also the amount of water needed to grow a successful garden. I decided to install drip irrigation that would be covered with mulch. I setup the irrigation on zones, and each zone was timed. Depending on the crops I could adjust the timer to allow more or less water. I set the timers for night time waterings beginning at 2 a.m., and saved my self tons of labor.
(drip irrigation installed in garden beds)
To maximize this particular garden I would plant multiple things in each bed. For example, the tomato wall would be fully planted with tomatoes, and in front of that would be zucchini and squash. Then below the zucchini and squash on the very edge of the bed I could plant things like chive and cilantro. I did this in all of my beds, and this is how I could grow 26 different edible crops in a space that was no bigger than 20' x 25',. Which is being generous because the garden ended up being the shape of a drunken whacked out trapezoid.
(shade loving plants under eggplant canopy)
(8' pea wall made of trellis)
(multi-tiered garden beds built on a slope)
Since I had limited space in this garden, and I wanted to expand it one year, I had no choice but to fence off an area in my driveway. In this expansion I used smart pots to grow things like jalapenos, tomatillos, serranos, and even pickling cucumbers in 15 gallon smart pots. I built yet another trellis wall for the cucumbers, and grew enough cucumbers to have year around jarred pickles.
(container garden expansion)
(cucumber wall built with trellis & plants in 15 gallon smart pots)
When dealing with pest issues in this garden the largest of critters I had to deal with were deer. With the size and shape of this garden a simple 4' wire fence easily kept them out. I did also end up putting in a squirrel proof bird feeder to attract birds to the garden to help cut down on pest issues. The only real problem I had other than Japanese beetles, and caterpillars on my tomatoes, was a groundhog one year.
(diy squirrel proof bird feeder)
This fat little bastard would waddle up and over my fence, and wipe out 3 cabbage before I could even get down to chase him off. It became a game of cat and mouse that lasted a week or so. He wiped out almost all of my cabbage, and I tried everything to get rid of him. I used repellents, live traps, and even coyote piss. Nothing worked, and I would just watch him decimate my garden in real time.
Needless to say, I did end up winning the battle, and sitting like a sniper on my deck became a daily ritual.
Other than that, this garden needed standard IPM practices for aphids, and powdery mildew. I would hand pick all of the caterpillars on the tomatoes, and also hand pick the Japaneses beetles. Other than that it was smooth sailing. In the winter months I could water 3 or 4 times over the course of the winter, and never had any pest issues. I began to enjoy the winter gardening as much as the summer gardening.
(ladybug looking for lunch)
With this small garden, depending on the year, I was able to grow between 750 to 1000 pounds of food for my family. I grew so much food that local farmers that worked the farmers market tried to convince me to stop giving food to my friends and neighbors. How ironic that was to me.
With a little planning, and a lot of hard work up front, you can set yourself up with a garden that produces high quality organic food year after year with very little maintenance, and a low amount of residual expense.
This particular garden I made completely out of cedar lumber. It was very expensive, but cedar can last upwards of 20 years. I believe at the time 10 years ago, I spent roughly $2,500 building this garden. That was for the lumber, soil, pvc, pots, etc... It could have been a little more, but I am just repeating to you the number I told my wife out of safety for my life. :)
That being said, each year after that would only cost soil amendments, seeds, water, and a few miscellaneous items. I could grow the same amount of food for only a few hundred dollars per year once the garden was setup.
How To Build DIY Raised Garden Beds For High Altitude Gardening.
So fast forward to me buying a house in Colorado, and living at roughly 7500' in the Rockies. The season here is so short. Like really short. The safe planting season is June 1st through about mid-September. A lot of people have a hard time getting tomatoes to mature in time, and gardens are mostly just containers people put out on their decks.
At this elevation, and in a more rural type setting, there are so many factors you have to deal with. First to consider are the predators. It is a lengthy list, and consists of mostly large predators. Voles, rabbits, bears, elk, and deer to name a few.
Think about this list for a second, the voles come up through the ground, the rabbits will jump into your raised beds, and can squeeze through cracks in fences, bears can climb over pretty much whatever fence you build, deer can reach over a low fence, or just decide to jump it, and the large elk can reach up over a larger fence.
I forgot to mention the sun at high elevation. At high elevation the UV is extremely strong, so strong that your plants will burn with to much direct sunlight. This is why most people up here can't grow tomatoes. If you do not combat the sun, your garden will not grow.
As if all of this was not enough, the summer hail storms were a regular thing at this altitude. Some years it would rain every afternoon, and more than half of those rains would actually just be a hail storm. Obviously balls of ice falling from the sky from high up in the heavens is going to destroy your garden. Yet another reason locals have issue with growing vegetable gardens.
Taking all of this into consideration, and the fact that I love challenges, I set out to build one of the most low maintenance gardens I have ever had.
Due to the nature of the vole situation it obviously has to be a raised bed garden. I did however have to factor in all of the other issues. I could not just build raised beds and hope for the best. This is what most locals did, and it ended with defeat. At best I would see some people build a fence. That deters a lot of the issues, but not all of them.
So after many drawings, and a lot of thought, I settled on building what I dubbed,
“The Thunder Dome.” I thought the reference was fitting for the all out battle I was going to have with mother nature in this less than hospitable environment.
The “Thunder Dome” was going to be just that, a full on garden fortress. I had to protect the ground, the walls, and the roof, from intruders.
For the ground I chose stainless steel marine grade wire that I would roll out and build the beds and the rest of the garden over. The voles could not penetrate the small squares, and the fact that it was stainless steel means it would never rust or rot. I'm not gonna lie, it's pretty damn expensive. If I remember right I spent $400 on that one roll.
(stainless steel marine grade wire for vole prevention)
At this point in the project is where all of my neighbors saw what I was doing, and said, “you can't grow food up here, and you are wasting your time.” “Game on bitches”, is what my brain said back to them, as I politely waived and nodded with a small smile. This was the retort from neighbors that had lived up here for 40 plus years. “You sir, are going to fail miserably.” I had a reasonable idea of the outcome, so I just played the long game. More on that after my first high altitude harvest.
(close up of stainless steel wire built into my raised beds)
(proof that the wire is indeed vole proof)
Once the marine grade wire was in the ground, I began building the frames of the garden beds themselves. This time I chose to use conventional lumber. It was purely a cost thing. I didn't want to sink in over 5k to build this garden, so I figured out if I used traditional lumber (which would only last 5 years or so), and sprayed a natural oxidizer on the lumber, then I could extend that to 15+ years of use. So this is the route I chose to go. I sprayed every cut end, as well as all sides, tops, and bottoms as I built the garden beds.
(framing the raised garden beds)
Once the frames were built I started to incorporate my 8' fence posts into the beds which would eventually make up my fence, and “roof.” I built these into the beds, screwed them into the garden bed frames, and eventually the bottom sections would be buried in the soil.
(setting the fence posts for the fence)
At this point is was when I began to fill my raised beds with soil. I did this because once the fence was up I would only have a small gate to load in yard after yard of soil. For this garden I chose to use a mix of top soil, and compost. It was a roughly 50/50 blend that I had trucked up from the City. I would choose to amend this with my own amendments once the garden was complete.
(amending my soil)
The next step was building the fence. I built a 6' tall fence around the entire garden, including the aisles you walked in. I also built a 6' tall gate with a latch that was the only entrance or exit to the garden.
(an elk trying to get a snack)
At this point most of the critters were handled. To be honest, there's not much you can do about a bear. If they want in, they will get in. I never had an issue with them once in the garden though. They tend to go after your trash cans first.
From a low altitude gardeners perspective this garden would be pretty much good to go, however we still have to deal with the sun and hail. To do this the best way to combat both with a single product is to use some sort of shade cloth. After researching the strength of the sun at my altitude I landed on using 30% shade cloth. It would block enough sun for tomatoes to thrive, but the holes were also tight enough to not allow hail to penetrate. I had a custom piece of shade cloth manufactured for my garden that was large enough to come down the side about 2'. This would help block any sideways hail that tried to come into the garden. The shade cloth cost for a custom cut a sown piece was roughly $100.
(30% shade cloth to protect form the UV & hail storms)
The one last thing I needed to focus my attention on in this project was watering. It's just not practical to hand water, and in the past I have always used drip irrigation. I decided to use the same drip irrigation system I used on my last garden, and put it all on a timer. Other than a few applications of Lactic acid bacteria serum, fish, or kelp throughout the season, the drip irrigation did all of the watering for me. Since it is so dry up here it is also a must to do a thick layer of mulch over the entire bed. This helps to retain water, and it made it so that I could water for only 30 minutes per day. I also timed my waterings to be around 2 a.m. So that there was no heat form the sun drying up the moisture.
(drip irrigation because I am lazy)
All that was left a this point was to fill the garden with my plants of choosing. At this altitude you are limited on what you can grow. Tomatoes are hard to pull off, but can easily be done with some care. I figured out if I stuck to Siberian style tomatoes I could have bountiful harvests. Zucchini, and squash grow very well, but you have to watch the powdery mildew. I would use a neem essential oil spray once per week to combat PM. You can't even skip one week, or you are screwed.
(completed raised garden waiting for plants)
Obviously cooler season crops like cabbage, broccoli, brussel sprouts, cauliflower do very well up here. Most herbs like cilantro, parsley, etc.. do well too.
(crushing the cabbage game)
The only major hiccup I had my first season in this garden was early blight on my tomatoes. I was able to stave it off enough to get a decent harvest, but it still took at least half of my plants by the end of the season. I never had it again after that first season though.
(master of the high altitude maters)
The one thing I didn't realize, because it was my first time to garden at high altitude, was that pests are almost non-existant. Other than some aphids late in the season, there were zero pests. I mean none, notta, zip. It was crazy coming from the south where you have pests 9 months of the year. Basically for about 3 to 4 weeks in the late season aphids would show up. With a simple soap spray, or some essential oils they were not an issue. Substantially in the following years I would leave weeds in my garden that the aphids were attracted to, and this would naturally keep them off of my food crops. It worked very well. They would be so thick on the weeds, you would eventually not even be able to see that it was a plant. It was just a giant gray aphid stick.
So remember my neighbors saying I couldn't' grow food at this altitude, when I first harvested I made sure to put a box of food on every one of their door steps. Needless to say, they were all amazed, and they thought I was a a plant whisperer. Honestly it was all the “Thunder Domes” doing, I was just the builder of the “Thunder Dome”.
(high altitude raised beds poppin off)
(high altitude raised bed garden in full bloom)
So whats the down side of this high altitude garden? The cost. It cost me somewhere in the range of $3,000 to build this garden. Again, it could have been a little more, but let's stick with what I told my wife it cost. The good thing though, is that each subsequent year I would spend roughly $100 to garden.
(elk formulating a plan of attack)
I am aware that this sort of input cost on a garden is out of a lot of people's reach. I like to use it as an extreme example of what is possible though. With a little thought, and some hard work, even in a place where people say you can't grow food, you most certainly can.
So Was This Just a Flex on How Much You Spend Building Your Raised Garden Beds?
Most certainly not. I am an extremist, and always want to build out the best I can for what budget I have. For most situations you can spend a few hundred dollars and have productive raised garden beds. I want to provide my real life experience with raised garden beds so that you can adapt whatever parts of it may work for your garden.
I have had some people want to replicate my exact style of high altitude garden because of how effective it was, but most people will pick and choose the things that they feel are the most important to get them to a successful harvest.
It doesn't have to take thousands of dollars to build raised garden beds, it can be as simple as creating some rectangles from 2 x 6's and filling them with soil. I want you to go away with the feeling that your project is now way more manageable than you thought, because at least you don't have to build an actual fortress to grow a few tomato plants. :)
That being said there are very economical options for prefab fabric raised beds that may be worth a look. I can tell you from experience they go together way faster than building raised garden beds. They can even be used in a situation where you may not be the owner of the property, and they need to be moved when you move. There are a lot of benefits to these style of raised beds, and the price is hard to complain about.