Learn to build your own raised garden beds to maximize your square foot gardening potential. Grow all your own veggies and produce at home in your backyard garden like a true homesteader with this basic tutorial. This is Chapter 3 of 11 of our Backyard Gardening Homestead Handbook.
You are reading Chapter 3 of our gardening series in The Homestead Handbook:
Raised Garden Beds For Square Foot Gardening
Some readers might be wondering why this method goes to the trouble of building boxes in the first place. After all, can’t we just apply the square foot rule to a regular patch of garden and get the same results? The truth is, probably not! The box system is very important to the health and success of your garden for a few reasons. First, it keeps your garden organized and simplified, which means you as a gardener are more likely to take good care of it in the first place. When you turn something from a chore into a joy, chances are good the activity is going to be done more! The boxes also do the hard work of keeping that special soil mix above ground and away from any pesky neighboring plants. It means you don’t have to worry about the potentially poor quality of your soil from affecting the outcome of your crops, or worry that your rich new soil mix will get washed away into the yard during heavy rains. The use of a box means it’s much easier to add features that further enhance the productivity of your garden, including shades and fences to keep out pests—including those “pests” on the bottom of your legs, your own feet. And finally, the boxes simply look nicer! They keep your yard clean, organized, and attractive. It may seem a small consideration compared to the crop yield you will enjoy, but you’ll find after you build your garden that you will appreciate the cleanliness of this system far more than the sprawl of the single-row system.
Now that it’s time to start building your garden boxes, remember you have a variety of options when it comes to materials used. If you have budget concerns—and what family doesn’t—this kind of variety will be important and allow you to get your garden built at potentially little to no cost. Oftentimes construction sites or other types of sites will be discarding exactly the type of scrap wood you might need for your garden box. Get creative! Think “outside the box” to find the materials for yours! You may end up saving your family a good deal of money.
Wood is the most obvious material candidate, as it is plentiful and cheap and easy to work with. Whether you decide on manmade or natural wood is your choice. Remember to avoid pretreated wood, as its chemicals could seep into your garden! If you must treat your wood, we recommend linseed oil, which will not harm your garden. If you do decide to paint the boxes for aesthetic reasons, make sure you do not paint the inside of the box for the same reason. It is simply safer to leave this wood untreated.
Other materials include plastic, vinyl, brick, or stone, or any material which you can find in lumber sizes. For the building example in this guide, we will be discussing the plans as if you have chosen wooden lumber for your material. If your garden is going to receive a low amount of traffic, this guide recommends 1×6-inch lumber. Gardens with heavier traffic, or boxes that need to be sturdier in general, should be built with 2×6-inch lumber.
First, cut all four pieces of your lumber or material to the same length. If you do not have access to power tools, your local hardware store should be able to provide this service to you at little to no cost, particularly if you purchase your lumber from them. After you’ve cut the wood, rotate the corners to build a perfect square box. Use coarse-thread deck screws which are twice as long as the lumber’s thickness to attach the boards, using three screws per corner. We also recommend pre-drilling your holes in the first piece of your first connector. This work should be done on a hard, flat, and stable surface like your concrete patio or driveway, or a garage workshop if you have it. Keeping the frame flat is very important so you do not end up with a crooked garden box when all is said and done.
After you have created the square, move it gently to your yard in the pre-planned area you set aside. Give it a look—is it how you imagined? Can you still access the full square footage of the garden from all sides? Are there any obstacles you didn’t plan for but now see may be a problem? This is your chance to ensure your best laid plans are going to work.
Earlier, we mentioned several reasons you may wish to put a plywood bottom on your garden box. This is not a necessary addition for all garden boxes; you will need to decide based on your specific needs whether it is a good idea. Some reasons you may wish to use a plywood bottom is portability of the garden box, or the nearness of trees or shrubs that may pose a risk to your garden’s root system. To attach a plywood bottom, measure and cut plywood sheeting to fit your garden box and drill ¼ inch drainage holes (1 per square foot, and 1 in each corner). Then attach the bottom to the frame and flip it over to proceed. We recommend 5/8 or ¾ inch plywood for a standard 4×4 box, particularly if you plan on moving your garden box frequently.
Here is a full list of the materials you will need before you begin the building phase of a basic garden box:
- Four 4-foot, 1×6 or 2×6 boards
- Six 4-foot wood laths
- Decking screws
- Power drill
- Landscaping fabric
- Your optimal soil mix
Take your four boards and stack them on top of one another in a “step” design. Drill 3 holes in one end the board, then slide that board back to do the same drilling in the next board.
Screw three of the deck screws into your pre-drilled holes until you have a complete frame.
Move your frame to the place you have designated for your garden. Remove any obstacles such as weeds and branches. Lay out the landscaping fabric and cut it to reach outside the garden box frame.
Take your optimized soil mixture to your garden box until the landscaping fabric and bottom of the box is completely covered. Take your garden hose and water the soil, then repeat a total of three times—adding new soil and watering until the soil is near the top of your box.
This is the basic design for building a square foot garden, but there are supplements and additional things you can do to enhance the beauty of your garden. One thing to consider is building a “pyramid” of your boxes, which only requires that you build several of the basic boxes and “stack” them. This creates an incredibly beautiful display that you can customize with flower and crop choice to really make your yard pop! Another option is to build your raised garden beds with extra depth. While you do not need any more than 6 inches of the optimized soil in order to have a successful garden, that doesn’t mean you can’t actually create more depth for your garden. Building deep boxes adds dramatic flair to your crop, and you don’t even need to spend the extra money filling the entire depth with the optimized soil—just put some ordinary sand in the bottom six inches, then put the optimized soil on top.
After your boxes have been built and placed, it’s time for the next important step—building your grid system! As we discussed previously, the grid is a very important part of the square foot garden. It allows you to maximize your crop yield in the smaller space, and is quite simply more attractive than a giant 4×4 box full of a mish-mash of crops. The grid you build for your boxes should be permanent and sturdy so that it can survive the constant sun and watering your garden will receive. There are several options of materials you can use to build a quality grid system for your raised garden beds.
The most obvious material is again wood, this time in the form of a wood lath, which is typically inexpensive and easy to find at a hardware store. The best part of laths is that they come with a lot of your work already done for you—they are typically 4 feet long with squared ends. Make sure you find laths that are straight and sturdy—since they are so thin, they can be prone to weakness. Lay them out and drill holes at 12-inch intersections, and then connect them together with any type of fastener such as a nut and bolt or a pin. If you’ve put enough of the optimized soil in the box, you should be able to simply lay your lath grid on top of the soil; if the grid stretches over the edges of your box, drill holes in the center slats to attach them to the box itself to keep it from shifting around. Depending on the climate you live in, this removability of the grid will be useful during the winter months—you can simply pick up or unscrew the grid and store it somewhere dry to keep its longevity.
Another option for grid material is the use of typical Venetian or slat blinds. Yard sales or goodwill stores are fantastic places to find discarded blinds; you may even consult the maintenance staff of an apartment complex, where damaged blinds are often discarded after tenants move out. This could get you your grid material at little or no cost, and is also a great option if you don’t have access to a power saw to cut material. The most important thing is to find a set of blinds that is at least 4 feet wide. Lay the blinds out and cut the connecting strings out. Use scissors to trim the blinds until they fit in your garden box. Use your drill to create holes at the halfway and quarter points, and attach the blinds at these points with a fastener like a snap-fastener, nail, or screw. Be advised that because blinds are so lightweight, you may see trouble with them laying still on windy days, especially early in the season before your plants have had a chance to thrive and block the wind. You may need to provide additional anchor points to fasten the grid to your box of raised garden beds.
While it’s not necessarily considered part of the garden construction, you should certainly put some thought into how you want your all-important garden aisles to look. Because of the efficiency of the square foot garden, you won’t actually be spending a huge amount of time in these aisles, which means you are free to customize them in ways you probably didn’t consider. If you’ve put your garden boxes on your existing lawn, there is no reason to worry about changing the aisles if you like the natural look of your green grass—you won’t be wearing out the lawn during your garden maintenance.
Another option you have is to lay down a mulch or shredded bark in your aisles. It’s important you dig out any weeds before you do, however, as well as a landscape cloth to prevent their return. Typically you want about 1-2 inches of mulch on top of the cloth to perform the job effectively. You could also use gravel, and there are quite a few options out there to allow you to create an original and attractive look. If you consider your garden box placement a more “permanent” installation, you could also create that permanence in your aisle construction by laying brick, paving stones, or even a wooden walkway. You don’t need to go through the expense and energy of laying mortar to do so, either, if you lay down loose sand and use it to fill the joints of your chosen materials. This kind of project can easily be done in an afternoon.
There are a few secondary structures you can build for your square foot garden, depending on your particular needs and wants. One of these is a dome support, which protects your garden and is very easy to make. Basically all you need to do is take two 10-foot lengths of ½ inch PVC pipe and bend it from corner to corner on your box. Once you bolt it at the intersection at the top, it creates a sturdy skeleton for any type of cover you may need. You’ve created your own little greenhouse! This protective dome will keep out insects and larger pests from your garden in the spring, and protect your plants from getting too much blazing sun in the summer.
There is one method of dome support that takes a bit more work and material, but it is worth it for its unique look and usefulness. This is the “covered wagon” dome. You will need the same two 10-foot PVC pipes and arch them over each end of your box. Next, take another section of pipe—this one is 4-feet long—and use it to create a supportive strut under the arch. You will need to drill holes in the center of the archway, and in each end of the strut, in order to properly and securely connect a bolt through it. Make sure you use a fastener or bolt that won’t be likely to tear through whatever material you use as your cover, which will probably be quite thin. If this creates a frame that is too tall for your needs, simply cut down the PVC pipes a few feet. Do not make the mistake of buying a single 10-foot PVC pipe to cut in half, because the arch over a 4-foot span will end up being longer than 5 feet once you account for the curve of the shape.
Another option for protecting your garden is to make a wire U-frame, on which you can build an actual “cage”. You can use fence material or chicken wire, both common materials that you should be able to find with ease and little expense. The great thing about chicken wire is that you can typically cut it yourself on-site with shears or pliers, so you don’t have to worry about making an extra trip to the hardware store if you want to adjust the size or design of your cage. They are sold in rolls at most hardware or gardening stores. Get yourself a roll now and you should have plenty for any future gardening projects if you use it economically. Chicken wire cages are ideal for protecting your garden against large pests like rabbits, birds, or deer. It also prevents any cats from coming to dig in the soil—they usually aren’t interested in your garden, but they certainly aren’t doing it any favors! Chicken wire cage also protects against stray balls during playtime or any debris that may blow through during a rough storm.
To construct a wire cage, you will need to build a wooden frame to support the wire on the bottom. Use the following instructions to build your wire cage:
- Attach four pieces of 1×2 wood, 4 feet long, in a box shape
- Connect the wood with two deck screws at each corner
- Cut your chicken wire to fit the frame; the height of the cage will be at your discretion and should be tailor-made to whatever the height and needs of your particular plants are. If they aren’t going to grow too busy or tall, you do not need to make the cage very high. Make sure you know what your plants will look like when they mature to prevent having to fix the fence as they grow!
- Staple the wire to the frame
- Be cautious to cover any sharp edges or areas with duct tape to prevent any injuries
- You should be able to drape additional protection, such as cheesecloth or plastic sheeting, on top of this structure to protect against sun, wind, rain, or cold at your discretion.
That was Chapter 3: Raised Garden Beds from our Homestead Handbook: How to Grow All The Food You Need In Your Own Backyard