Introduction: Build a Concrete Block Garden for Food and Memories
WARNING: GARDENING PUNS BELOW
This is my first Instructable. It details how we developed and built a raised bed garden out of concrete blocks (or concrete masonry units). It includes relevant photos of the process, accompanied by my incredibly witty, eloquent, and sometimes excessive commentary, discussing why we chose to make certain decisions, as well as discussing our successes and missteps along the way.
DISCLAIMER: I have updated this Instructable with relevant links to products on Amazon. I am a participant in the Amazon Services LLC Associates Program, which is an affiliate advertising program designed to provide a means for me to earn fees by linking to Amazon.com. I'm in no other way affiliated with Amazon Services LLC. Amazon and the Amazon logo are trademarks of Amazon.com, Inc. or its affiliates.
Introduction: How We Got Here
Living in an apartment has its perks and its drawbacks. For several years my family inhabited a small townhouse/apartment in a duplex which had limited space inside and even less space outside to call our own. The back "yard" was a 12'x12' patio that sat in the shade 24/7/365.
At the time we were budding hippies and really wanted to be able to grow our own produce. We decided that since we couldn't bring the sun to our garden, we'd bring our garden to the sun -- and so the San Diego Truck Farm was born.
Driving around San Diego in a 2009 Tacoma with a live greenhouse in its bed brought its own challenges. The produce was good though, and it was a great opportunity to share my growing passion for gardening with the community, who loved to ask questions and see how everything worked. Unfortunately, with gas prices topping $4.50/gallon, the money saved in produce was easily overshadowed by the money lost to the fossil fuel industry. After a single (successful) growing season, the truck farm was retired.
In 2015 my family moved to North Carolina, where we could afford a nice house with a yard. We got the gardener's itch again. After multiple trips to the doctor and topical creams, the itch was tolerable, and we set out to figure out what to do next...
I've never been one to shy away from a challenge, and if the truck farm is any indicator, I like to make things complicated, eccentric and generally awesome if I'm going to make things at all.
What Type of Garden is Right for you?
There are 3 types of home gardens that come to mind.
- JUST DO IT
Depending on where you live, it certainly can be practical to just throw down some seeds onto the ground and hope your soil is accommodating enough to work for you. If you do go this route, I recommend getting one of these packs of heirloom non-GMO seeds. Buying in bulk is a lot cheaper than buying packets at the store every season.
- POT POT POT
Potted plants are the poor man's raised bed. They work great for certain types of plants, but not so great for others. Potted plants can also add a lot of decorative appeal if that's the kind of thing you're looking for. But they're not great for larger gardens... unless you want a million pots sitting around your yard. You also have to be cautious of what plants grow well in pots. Not all plants do. The Vegetable Gardener's Container Bibleis an excellent book to get started if you're going with pots.
- RAISED BED
Raised beds are all the rage. There are lots of ways to go about doing them. You can just pile up some amended soil. You can make some simple wooden frames out of cedar. Lifetime makes a good, simple HDPE (high density polyethylene) 4x4 raised bed kit you can get on Amazon here. I prefer the look of cedar, but even cedar needs replacing eventually. HDPE should lost for a long... long time.
We chose to build a raised bed because it would allow us to control our soil better. We also wanted an aesthetically pleasing garden plot, specifically portioned out in our yard. And lastly, we wanted to build it in a manner that would be modular, have the ability to get upgraded or changed somewhat easily, and provide a lot of growing room.
What Type of Material to Build a Raised Bed Out Of?
The easiest answer is probably wood. Lots of big box home centers sell some very simple 4'x8' raised bed kits like this one from Amazon. These are super simple like the one from Lifetime I mentioned above, and provide a decent amount of growing area, but what you see is what you get. If you just want to get going fast, these are a good solution. They're not very "raised," so to speak, but they allow you to customize your soil and get to growing quickly.
We opted out of cedar, because I like to go big and develop new skills with each project I take on.
I'd never worked with masonry, foundations, excavations, and the like... and so a new hobby was born.
Why Concrete Blocks?
I chose to build our raised bed out of concrete blocks because... well... it seemed like a good idea at the time.
- Concrete blocks are relatively cheap in bulk quantities
- They are modular and easy to work with (other than their weight)
- They are easily replaced if they wear down or break
- They are semi-permeable which is excellent for drainage
- They are aesthetically pleasing if done right
- They allowed us to easily customize a layout for the garden
- They are heavy enough to allow a decent soil depth without succumbing to the weight and falling over
- ... I promise, they'll grow on you
The Most Important Part of Any Project
Have fun with it. If you're not learning and you're not enjoying the experience, then you're not doing things right.
This garden became a tremendous undertaking, costing much more than I had ever planned and occupying my time sporadically over the span of nearly 2 years. In many ways, this project is a time capsule; a chronological record keeper of some incredible memories, achievements and life stories over the past several years.
Since beginning the project, my wife and I both got new jobs, adopted new pets, met new friends, made new memories and gave birth to our first child.
Now every time I look at the garden, pick a vegetable, or reminisce about the experience, I feel like it was all worth it, because in the end, our lives are but a sum of such memories and experiences.
I hope if you undertake a similar project, your experiences and life stories during the construction are as wonderful and memorable as ours have been.
Thanks for reading, and enjoy!
Step 1: Planning & Materials
I like the "just do it" approach for most things. As long as you can afford mistakes, there is no better teacher than failure or trial & error. With that being said, this isn't a "cheap" project, and it's best to go into it with an idea of some basic costs and materials.
This is not an exhaustive list, but it should get you started.
- Concrete Blocks*
We bought our blocks by the pallet from a big box store. The delivery fee was about $60 for a full pallet. Depending on how many rows you plan on, and how big your garden, will dictate how many blocks you will need to start. If you have a truck, this is a lot cheaper.
*These are not "cinder blocks," which contain coal/fly ash and have been known to be carcinogenic. Generally, from our research, concrete blocks are safe to use, and the biggest risk seems to be adding some alkalinity to your soil. But please do your own research and decide for yourself.
2' Spirit Level
Depending on the size of your plot, you may want a longer level, but 2' is a pretty usable size. You'll use this to ensure your row of foundation blocks are level before you start stacking, mostly so that it looks nice in the end. I tend to like Stanley products in general. They seem to last.
- Stanley Torpedo Level
This level is best used for the individual blocks as you lay each one. Although I really like Stanley products, a trend I've noticed with nearly all torpedo levels I've owned is that they are not perfectly flat. It's always best to use your larger 2' spirit level to double check your work after you've laid several blocks.
- Line or String Level
Also called a string level, sometimes. You get the idea. We want the darn thing to be level! If you use stakes and a string to define your area, all you need to do is pull the string taught and then clip this level to it. Super simple.
- Paver Base
This can be obtained by the bag from your local big box store, but to do so is incredibly cost prohibitive. I recommend finding a local mulch/gravel yard that can deliver or provide this in bulk. It is sometimes called "ABC," "road base," or something similar. It generally consists of a mixture of sand and 1/4" to 1/2" crushed rock. It compacts well and provides for important drainage.
You'll want around a 6" layer of paver base for your foundation, so be ready to get a lot of it!
Wherever you get your paver base from should also have sand. You'll need about 1" of sand on top of your paver base to help set and level your blocks.
- Fiskars Digging Shovel
I can't stress enough the importance of getting a good shovel. For the first portion of my excavation I was using a standard issue USMC entrenching shovel. Great in a pinch, but not for a leisurely excavation project like this. Get a shovel with a long handle and save yourself some back-ache. Fiskars is mostly known for sharp cutting tools, but they also make durable, great shovels.
- Square Shovel
Not as critical as the digging shovel, but useful for removing large amounts of loose or excavated dirt. For our purposes it's especially useful because it's the perfect size for clearing out the trenches we are going to dig with the digging shovel/spade.
- String Line
The string line I've linked to is not the exact line I used, but it's the one I wish I had. It's nicer because it comes on a spool and includes a line level. I was cheap and just used a standard roll of line which I already had on hand, and which became a horrible tangle of string that kept having to get cut and re-tied over the months. Be smarter than I was and go with the spool.
- Wood Stakes
Just in case you have a vampire problem. Also useful for helping to level your string line and set the height of your first course of blocks. Don't go overboard on quality, you just need something easy to pound into the ground and which won't budge under the string's tension. You can get these from big box stores usually, but you might find a better bulk deal on Amazon.
- Rubber Mallet
You'll use this to help set your blocks in the sand/base. It's very important if you really want to do it right.
Quality is not critical, but it's very helpful to have a good wheelbarrow with a good wheel. Mine was a loaner from a friend with a broken left handle and a flat tire. Be smarter than I was. The Worx Aerocart I linked to is one I've really been itching to order; I'm just waiting for my friend to ask for the loaner back!
- Heavy Duty Tarp
Depending on how long your project takes you, you'll want a couple tarps set up to hold your gravel/sand/soil materials. In my case, the scope of the project quickly got out of hand, and we were left with two large tarps in our back yard for almost 2 years. Everything under them died and it will be at least another season before anything grows where they were. Be smarter than I was! You don't necessarily have to get a heavy duty one, but if your project takes a little longer, you'll want a big 20'x30' one like the Drytop Heavy Duty Tarp that won't turn to dust if left outside for too long :)
Everything is better with a buddy or buddies. Enlist the help of your friends. Pay with booze if possible. If you can guilt a spouse into helping, that's double-rewarding as well!
That's really it for the garden itself. I'll go over materials for some of the extra customization as we go on. But for the most part, the tools required to build the block layout are the same as would be required for a simple paver patio.
Getting a solid visual idea of what you want to create is important. Some things you can just wing, but since you're going to be doing a lot of physical, manual excavation, you'll probably want to get it right the first time if possible.
The dimensions of each concrete block are actually 7 5/8" x 7 5/8" x 15 5/8". This is very important to remember, because that 3/8" difference, multiplied by, say, 20 blocks comes out to about 7.5" in variance, which is nearly half a block. So if you make measurements using the common block dimensions instead of the actual block dimensions, expect to be off by a lot.
I went through many stages of planning.
We plotted on graph paper, estimated height, took a few measurements of the slope of the yard and made a few sketches (speaking of which, you'll also want a good Stanley Tape Measure! Ok, you don't have to get Stanley, but why reinvent the wheel? You don't want to plan too much, but you definitely don't want to not plan enough. Ultimately we ended up in analysis paralysis and started getting frustrated by some of the details.
Once I had a decent design on graph paper, I decided I'd just modify as needed for any discrepancies as I went along. Your mileage on this may vary, but... be smarter than I was.
Our design would consist of 3 shorter beds, about 3' wide by 9' long, and one long bed connected to them. We wanted the beds narrow enough to reach across, high enough to not have to bend all the way down, and large enough to plant row crops as well as square foot gardening plants.
Step 2: Lay It All Out
You've got most of the materials. You've got the basic plan. Now lay it out.
I measured the diagonals of the four corners to ensure it was as close to square as possible, and adjusted, adjusted and adjusted until it was. After that, I set additional stakes for each of the garden's "legs" or "sections." Each of these would need to be individually squared as well.
Once everything was square, I drove the stakes until the ground and tied off a grid using the masonry line. This gave me a guide of where to dig. I also set the masonry wire to the level that I wanted the finished height of the garden to be at. I used the line level to ensure the string was level all the way around.
Due to the slight slope of my yard, I also had to dig deeper in some areas in order to keep the blocks at an even height. I also had to adjust my estimates/measurements of the quantity of gravel and sand I would need, because of this height difference.
Excavate: Work Smarter, Not Harder
I rarely live by the above mantra, but I'm keenly aware of it. In this case, I could have excavated the entire garden plot to a specific depth. It would have made the construction portion fairly easy because it's relatively easy to level a large, open plot.
However, I didn't want to have to excavate so much soil due to the labor involved. I didn't want to rent any big, fancy machines for the excavation, and I also didn't want to have to manually dig out and haul via wheelbarrow more than 3 or 4 cubic yards of top and subsoil.
Instead, I decided to only dig out the foundation trench, and keep a native soil underlayment in the garden's interior. This saved a LOT of digging, but added hours of work in leveling and measuring. It also saved a considerable amount of materials, in that I only required enough paver base and sand to fill the foundation trench rather than the entire garden.
I used my digging shovel to trench out my foundation. I foolishly placed the excavated dirt into the middle of the garden, where it would have to be moved again as I dug inward. This was a running theme of this project, wherein I consistently put my excavations in horribly inconvenient spots and had to move it again and again. Be smarter than I was.
As I went along, I moved blocks into place to ensure things were lining up as evenly as possible. Each block weighs probably between 30 and 50 pounds. I'd move them in and out of place multiple times. There were 108 blocks total. I'd estimate that in the process of digging, measuring, and moving blocks, about 40,000-60,000 pounds were moved back and forth.
This is ok if you're looking to burn some calories. But it shows the tremendous value of having accurate plans so that you don't have to constantly double check your work.
In the 90+ degree, 90+% North Carolina summer, it's good to have some help in this process. We rescued a black lab from the shelter, and she joined our golden retriever in helping me with the project. They didn't appreciate the heat any more than I did, but they did their fair share of excavation.
At this point I had realized I'd underestimated the physical labor that would be involved in the project. I started in August, during the peak of a hot Carolina summer. Poor planning and poor execution meant I had to double and triple the work in some cases.
In woodwork they always say measure twice, cut once. While it's fun to play trial and error, I think the same is true with masonry and excavation. The amount of work I could have saved by getting accurate measurements the first time around really is immeasurable.
I had never done masonry or excavation before, and so some of my ideas for laying out my grid did not pan out. I ran into a few other obstacles as well when it came to my measurements and getting things square. I learned the "diagonal trick" a little too late. If the measurements across the diagonals of your square are equal, then it truly is square.
I had also begun to break the project up into multiple days, which became a true momentum killer. The unrelenting heat made it difficult to work on it for more than 1-2 hours at a time, once or twice a weekend. And so this initial excavation portion stretched out into almost 2 months.
Step 3: Fill & Level the Trench, Set the First Course
The excavation portion was truly intense. To complete the digging, I moved many, many tons of dirt and concrete blocks back and forth across small distances, many, many times. It was quite exhausting and once I got around to filling the trench in, I was starting to wonder what I'd gotten myself into.
But I'm no quitter.
A standard base usually consists of a drainage layer composed of a sand & gravel aggregate. This layer is about 6" deep and is tamped down with a hand tamper (which I forgot to mention earlier), compacted, and leveled to form the sturdy, well-draining base of our foundation. To get the amount of base I would need, I took the width of my trench, and the approximate 6 inch depth, and multiplied by the total linear length of the excavated area.
I then arranged for a friend with a heavy duty truck to help me transport said base from the gravel yard back to my house. We needed about a cubic yard of it, which probably weighed about a ton in total. We then manually moved it from the front of the house to the back with a broken wheelbarrow over many, many trips.
On top of this base will go an approximately 1" layer of sand. The sand does not need to be tamped down, and is mostly used to seat and finely-level the concrete blocks. It helps if the sand is slightly moist when you get to this stage.
Don't underestimate the leveling step
Getting everything level the first time is critical to getting a perfect end product. If your base isn't level, then just like your measurements earlier, the height difference will get compounded as you stack blocks up, and it will look unsightly.
If you're ok with a little unevenness, you can save yourself a ton of time by just eyeballing it. But I'm not ok with that, and so I made it perfect.
This involved moving the base from the tarp to the trench by the wheelbarrow and shovel-full, and manually and tediously leveling every 4 feet of it. Had I chosen to excavate the entire square area, at this point I could have rented a plate compactor to tamp everything down nearly effortlessly.
Since I'm not a fan of "effortless," I use my 10 inch hand tamper (which I prefer to the 8" one linked to earlier) to manually tamp and compact everything down. I then used my 2' and 4' spirit levels to ensure that my base layer was level. Any uneven spots I would re-excavate, or fill in with additional base.
This was, again, very, very tedious, and labor intensive work.
Fun in the sandbox
With the base layer in place, start dumping the sand. I chose to do the sand in portions to ensure I got everything level the first time around, and because I knew I wouldn't be able to do it in one sitting.
I would shovel a few shovel-fulls of sand on top of the leveled base layer, then individually place and level a block. I'd then place and level the next block, and then use my 2' level to ensure both blocks were level with each other.
Like everything else, the leveling of the blocks was tedious and tiresome. Minor adjustments are not so minor when they are being made to 40 pound concrete blocks.
If a corner or section of the block is not level or even, pick up the block and add/remove sand as needed, then re-seat the block and re-check it.
A rubber mallet comes in incredibly handy here. Use it to hammer the block down and help to forcefully level it if you can.
Rinse and repeat this process all the way around until you have completed your first course.
For my garden that meant 54 blocks and about 1/2 a cubic yard of sand or so with a little left over.
Some important milestones
During this portion of the project, time seemed to stand still. The heat was so intense on the days I could work on it, that I was again limited to only an hour or so at a time. The yard grew quickly and threatened to grow over the project, so I was constantly combating the weeds and grasses as well. It would not have been an issue had I excavated the entire area.
As I sat on my laurels and brooded about how long the project was taking, my wife and I conceived our first child. We also both started working new jobs and had a lot of great improvements in our lives.
The garden took a back seat for a while. Once my wife came closer to giving birth, I thought about how little time I'd have to work on it after she gave birth, and so I got a second wind.
I bought a shade canopy and then beat myself over the head with a shovel for having not thought of it sooner. The canopy dropped the heat by 20 degrees, or so it felt.
In the following 3 or 4 weeks, I got more done than I had in the previous year.
I finished the entire first course of blocks, and, despite my many setbacks and mistakes, they fit perfectly. The entire garden was perfectly square, and I was content.
Step 4: Backfill
With the first course of blocks set and perfectly level, it was time to backfill the trench. With all of my remaining gravel and sand, I simply filled in the gaps surrounding each block. I used my hands and a small garden trowel to fill the block cavities and help lock them in place.
I filled the trench until it was about level with the soil around the garden.
One issue I had not planned for was the lower end of the garden, where the first course of blocks sits level with the soil around it. For these blocks, the backflll tended to roll out onto the surrounding yard.
I solved this problem later on by loose-seating some patio pavers on the perimeter to keep everything inside.
I used extra gravel and sand to fill the inside of the garden. This step wasn't particularly necessary, except that I needed something to do with the excess. It had the added benefit of creating an extra drainage layer and buffer between what will be my garden soil and the native soil below.
The foundation was now looking excellent, and I started placing the remaining blocks in place for the second course.
Step 5: The Second (or Third?) Course
Depending on how high you want your bed, you can start stacking your second or third courses. I wouldn't go much higher than 3 courses though, if you are only dry-stacking your blocks.
The amount of outward pressure created by wet soil is pretty substantial and can easily topple your blocks if they are stacked too high (even if they are glued or cemented in place). This can create a safety hazard if you have little ones running around as well.
We chose to keep ours stacked 2 rows high. This gave us at least 8 inches of planting depth all around in our raised bed soil. We did not use a weed barrier because we felt there was enough depth to prevent them from proliferating, and wanted to allow deeper-rooted plants to access the subsoil if needed.
2 rows in height also looks nice and neat without being too dominating of a feature in the yard.
Assuming your first row of blocks was perfectly level like ours was, the second or third rows should be a simple matter of just sweeping off the first row, and placing the second and third on top. No muss, no fuss.
I temporarily placed some paving stones in between the beds to help keep the grass from growing out of control while I finished things up.
Step 6: Growing Media
There are lots of different opinions on the type of media to use for a raised bed.
There's something called "Mel's Mix," which is a popular choice among square foot gardeners. Mel Bartholomew wrote a the book on square foot gardening where he breaks down this particular soil mix further. Unfortunately it's pretty hard to find everything needed for it, and it can be a little cost prohibitive (why I care about cost at this point, is beyond me).
As we got ready to fill the garden with soil and plant our first plants, my wife gave birth. I think it's symbolic, but maybe I'm reaching. Quite an exciting time, and a fun milestone.
If you can't afford a fancy mix like Mel's, some people have had success with growing in pure compost. The compost I could find locally was created from unknown sources. The only compost I could find that seemed reputable and "safe," was mixed with a 50/50 compost/topsoil mix.
This seemed ok to me, if for no other reason than I'm a total amateur and still figuring things out.
I found another friend with a truck, who helped me get almost 2 cubic yards of compost/topsoil mix back to the house. If my measurements were right, this would fill the bed to within 2-3 inches of the top. I didn't want to fill it all the way in order to prevent it from falling all over the sides.
The 50/50 blend we used should have enough compost to keep the plants nourished and a healthy mix of soil/compost to aid in water retention and/or drainage... or something!
Making it Pretty
Although it looked decent already, I decided to make use of some extra paving stones we had lying around from an unfinished patio that the home's previous owner had started. We had exactly enough stones to surround the garden.
These also helped keep the growing media IN the garden on the taller side (sloping down), because they covered the exposed holes in the base block layer.
We locked the stones in place by sweeping sand into the cracks and then pounding some aluminum landscape edging similar to this around the entire perimeter. Shop around for this stuff to try and find a good deal, because it can get expensive, but it adds a nice look.
I also bought some cheap solar garden lights on clearance and put them in all the corners. With extra gravel and sand, I filled some of the block cavities to add weight and support.
Step 7: Adding Plants!
It was fitting now that my daughter was born that we also let the garden get to growing.
We were getting late into the season already and so we bought some seedlings that we hoped would mature in time to beat the first frost.
We bought kale, collards, brussels sprouts, cauliflower and broccoli seedlings. We planted from seed turnips, beets, radishes and a variety of lettuces to start. We also got some snow and snap peas, but didn't have high hopes for them due to the time of the season.
I won't get into growing and planting, because there are exhaustive sites and forums that deal with that already.
I will say that we decided to go with square foot gardening for our first attempt and, other than some unseasonable weather, it yielded ok results.
Step 8: Pest Control
Up to this point my dogs had been great, fun helpers.
As soon as the plants went in, they decided that all my efforts weren't worth a damn. They really wanted the veggies for themselves. We also have a lot of rabbits in the area.
So I decided to build a pest barrier. The modular nature of the concrete block design really came in handy here.
I chose to use 1" PVC pipe and some fast setting concrete mix to create "fence holes" in the blocks. In those fence holes, I seated some 3/4" PVC supports attached to 1x2" pine fence panels covered in chicken wire. You can go heavy duty and use actual hardware cloth, but chicken wire is easier to work with and perfectly capable of keeping out most pests.
The concrete mix can be any of your choice. I like the fast setting stuff, which is often used for setting posts and cures quickly.
These panels were created by mitering the edges of 1x2 pine and using my Kreg Jig to drill pocket holes to connect them. I then laid out the chicken wire over the tops and stapled it in place. Speaking of the Kreg Jig... it (other than my drill, which is required to use it anyway), is easily the most useful tool I've ever bought. If you don't have a Kreg Jig already, get one now... whether it's for this project or for anything else. It's amazing.
You don't need to miter the frames, but I think it looks better, and I think it generally joins better than butted wooden members anyway. I also already happened to have a nice DeWALT Dual Bevel Compound Miter Saw that I love using about as much as my Kreg Jig. If I had to cut each miter by hand with a miter box, I would have skipped this step and just butt the frame members together. Not that a miter box is hard to use, but it would have been too tedious with this many cuts.
For the PVC supports, I needed to find a fast way to drill a lot of holes consistently in the same spot. I ended up needing 15 panels, each with at least 2 PVC supports on it. Each PVC support would have 2 holes drilled into it to fasten it to the fence panel. So I would need to drill at least 60 holes in 3/4" PVC in the right spots.
I set up a quick jig on my Skil 10 inch drill press by using a block of wood and a spare PVC pipe with a nail in it to gauge the proper length at which to drill. This was a crude method, but it worked surprisingly well. It took me a while to figure this jig out, but once I did, I was able to drill the holes in a matter of minutes. I then just drove screws through each PVC pipe and into the wooden panel frame.
A trick I learned with chicken wire was to staple part of it in place, and then use some kind of prybar (like a screwdriver) to pull it tight while stapling the rest. It wasn't critical to get the panels perfectly tight, but it's a little more visually pleasing than wavy chicken wire fence panels.
For security, I stapled at least every other chicken wire section down, which may have been overkill. You can probably get away with stapling more sparsely and saving some money on staples.
Concrete is fun to work with, but it can be nerve-wracking because of its permanence. After all this time working on the project, I didn't want to screw something up at this juncture.
So I measured multiple times and calculated how many bags of concrete I'd need. Turns out I needed a lot. Each bag could finish about 2.5 of these fence panels. With 15 panels I needed at least 6 bags of concrete. Not bad, but not fun to carry around either.
The fast setting concrete I used is designed for post holes and it's a dry mix version. I set my 1" PVC "post holes" in place, after measuring their correct distance. I then scooped concrete into the hole around them to set them in place.
I did a loose, dry fit with the associated panel to make sure everything lined up, and then I just added water to the dry mix according to the instructions.
Once the concrete had set in the blocks, I simply slid these panels into place.
The panels were not perfect. The wood I used was very rough-cut lumber. Some was warped or crooked. The panels don't line up perfectly. But it's close enough and it keeps a dog or a rabbit from getting in, that's for sure.
The panels are also simple and cheap enough to recreate should they get overly damaged.
A note on modularity
So another good thing came out of my need for fence panels. I added additional post holes in some of the blocks to future-proof the garden a bit. I didn't know what I'd need these holes for yet, but figured maybe I could make some hoop-houses or trellises or something like that in the future.
Step 9: Irrigation and Weather Proofing
I had intended to add drip irrigation to the bed since the beginning.
I spent a lot of time (maybe too much) researching how to cleanly deliver water all year round. I ended up accepting 2 truths:
- I probably wasn't going to be able to be 100% lead-free and non-toxic.
- I probably wasn't going to be able to water in the winter
Unfortunately, unless I chose to add a dedicated irrigation line, branching off my water main line, I was going to have to expose my irrigation system to lead components at some point or another. There are lead-free versions of most irrigation fittings, but not all. And in order to accomplish the goals I wanted, I just accepted that some of my hose connectors would not be lead-free. From a cost-benefit perspective, it's still a lot cleaner and cheaper than what I'd buy to eat in the store, so I can accept this small sacrifice. We will not be drinking any of the water, however I am unsure of how/if lead transfers from the soil into the plant via its roots.
I also spent a long time researching how to frost-proof a drip system. While there are some ways to help mitigate risk, nothing is certain, and the amount of work involved in doing so outweighs the benefit. In this region, it gets cold enough that you really don't need to water in the winter much anyway, provided it rains on occasion (which it does).
Drip Irrigation Requires:
- Some type of backflow prevention device like this lead free vacuum breaker. This is important to protect your home and municipal water supply. Local regulations may dictate what type of backflow preventer you require. Some municipalities are more strict than others, and to do it RIGHT, you might need to spend considerably more on a fancy backflow prevention device. In our case, we are allowed to use a simple hose bib attachment called a pressure vacuum breaker.
This just keeps water from your garden, which may be contaminated with chemicals or fertilizers, from getting siphoned back into your home's water supply by mistake.
- A timer if you choose
We bought a simple, hose connected, battery powered, single valve timer by Orbit. Orbit (and others) also sell multiple valve timers as well, so you can control different watering zones at different times. We may upgrade to something like that in the future, but for now most of our plants need about the same amount of water, so a single zone works. You can also control water delivery in other ways, like through various drip emitters.
- An inline irrigation filter
This is used to keep your drip lines clear of debris. Even small debris and particles can clog up your drip emitters, which would be no good.
- A pressure regulator
Water pressure from the hose bib at our house comes out over 60 PSI. That's far too much pressure for a drip system, and would likely burst and break the emitters. Here is a 25 PSI pressure regulator, which is safe and efficient for a drip system. We used a 20 PSI one, but could have gotten away with 25 as well.
We bought a lead-free, drinking water safe hose to deliver water from the hose bib and timer to the garden bed itself. I feel my recommendation is a good one, but please do your own research as there is some debate about which hoses are really safe for potable water.
- Main dripline
Our main drip line distribution tubing is about 20 feet long and just connects from the hose to several branching lines. Each garden bed "leg" has a main line branching down it.
- 1/4" Dripline
The 1/4" dripline distribution tubing is used to deliver water from the mainline directly to the plants. At the end of each small 1/4" drip tube is a drip emitter. These can vary, but we use 1/2gph Rain Bird emitters on almost all of ours.
- Associated connectors
Depending on your setup, you'll need certain connectors to lay out your lines the way you want. Drip systems don't like sharp or uncontrolled bends and turns, so use Raindrip 90 degree compression elbows when needed. You'll also need specific connectors to connect to your hose.
Irrigation can be complex and require some finesse and fine-tuning. It is highly dependent on what plants you are growing, where you are growing them, and how often you intend to water.
During the summer months, we water our plants once a week for 9 hours. This ensures a long, deep watering without wasting a lot of water. With our bed it's easy to tell when the soil is saturated because we can clearly see excess water leaching from the holes on the sides of the bed. This is a good indicator that the soil is well-enough saturated.
If your location experiences freezes, it's best not to have a permanent system installed. It's easy for lines to burst during a freeze and it can get expensive to repair. Part of our weather proofing was keeping the drip system modular enough to easily remove.
Once we got indication of the first frost, we simply unhooked everything and took the timer inside.
When that first frost did finally creep up on us, the extra "post holes" we added to the concrete blocks came in handy immediately. On short notice we cut some PVC pipes and placed them in the holes to create some hasty hoophouses.
We covered the hoophouses with sheets during a freak and sudden snowstorm and every one of our plants survived the frost
Step 10: Grow Some Plants, Grow Some Memories
If you've been following this Instructable by the letter, then by now you've spent 2 years turning a patch of dirt into a slightly raised, slightly more visually appealing, and a million times more rewarding patch of dirt.
From here on out, it's all gravy.
Read up on planting seasons, starting seeds indoors, special irrigation and fertilization tricks. Learn about climate zones and which plants thrive in certain ones.
One of the greatest aspects of taking on such a large and time consuming project, is the number of doors it can open to you for expanding your skill set, building your knowledge bank, and cultivating new hobbies.
For us, we not only built a fun (though expensive and sometimes frustrating) garden, but we used the documentation of the process to help build a chronology of our own personal adventures and family growth during that time.
We wish you the best of luck in pursuing a similar project, and hope it can be as fulfilling for you as it was for us.