Raised Planting Bed & PVC Structure

Posted by : Jared Frank On : May 30, 2014

Category: Construction, Garden, How-To, Off-Topic

Adapted from Trellises, Planters & Raised Beds (see citation below).

Source Material:
Trellises, Planters & Raised Beds: 50 Easy, Unique, and Useful Projects You Can Make with Common Tools and Materials. Minneapolis: Cool Springs Press, 2013. Print.

Prior to the start of the Maryland summer growing period, I decided to prepare a raised bed garden for growing vegetables in my yard. Although I’m working with a half-acre of land, there is no fence installed and we have daily, and especially nightly, visits from rabbits and deer. As such, a protected raised bed was a perfect way to grow vegetables safely along with the added benefits of reduced soil erosion, an almost nonexistent threat of weeds, and overall improved water drainage (especially helpful with the way our property is laid out). Since this is the first raised bed on the property, I decided to try a frame built from 2″ x 10″ lumber, with a length of over 8′ and a width of roughly 4′. Specifically, the outside dimensions of the raised bed frame are 8.33’ x 4.00’ x 10.00”. The PVC frame will feature a rectangular structure covered with netting versus a conventional hoophouse structure.

Tools & Materials:

Stanley Powerlock 25’ x 1” Tape Measure
DeWALT 7 ¼” Lightweight Circular Saw w/ Electric Brake
Stanley ShortCut Saw (Handsaw)
Pencil/Pen/Permanent Marker
WeatherShield 2” x 10” x 8’ #2 Prime Pressure-Treated Lumber x3
WeatherShield 1” x 2” x 8’ Pressure-Treated Board x4
DeWALT Drill/Driver Kit w/ DeWALT Drill Bit Set & DeWALT Square-Driv Bits
¾” x 10’ PVC PE Pipe x5
Easy Gardener 14’ x 14’ Mesh Netting x1
Level/Square/Straightedge
GreatNeck Spring Clamp Set, 16-Piece x2
DeWALT 5-in-1 Hacksaw
MAGBIT Tube Cutter
3 ½” Exterior Wood Screws x16
1 ½” Wood Screws x12
LASCO ¾” SCH40 Side Out Elbow x4

How to: Build a Raised Bed w/ PVC Structure

~ Step One ~

For the first step in the construction of this particular raised bed, you will need the following tools/supplies:

Use a circular saw or handsaw to cut one of the 2” x 10” x 8’ pieces of lumber into two equal 2” x 10” x 4’ sections. Trim the other two 2” x 10” x 8’ pieces as needed to measure 8’ exactly, though I didn’t bother with this step since both pieces were roughly the same size. A square or straightedge can be beneficial in making straight cuts. Then, take the two ends and set them over the side pieces, instead of vice versa because I wanted to add a little extra length to the raised bed, so that they are flush at both the top and outside edges. On the outside of the two 2” x 10” x 4’ end sections, at both sides, use a pencil to draw four markers, roughly one every two inches, though your spacing may vary, one inch from the edge, down the height of each piece. Next, use the square and the level to line up each end piece with the ends of the two 2” x 10” x 8’ side pieces, as shown in the below pictures, and then use the power drill to prepare pilot holes accordingly, through the end pieces and into the side pieces. Once done, fasten them together using 3” galvanized wood screws.

~ Step Two ~

Next, instead of cutting and installing corner posts into the four corners of the raised bed to internally support the frame, as we’ll need that space for the PVC structure, we will support the frame solely through reinforcing the outside of the frame.

The following tools/supplies will be utilized for this step:

First, take two of the 1” x 2” x 8’ pieces of wood and cut them into two equal sections. Using clamps, hold these pieces in place, with a 1” extension past the edge of the raised bed frame, on each of the four outside corners. Then, take the measurement of the space in between the two extended pieces on either side of the frame. The distance between the two pieces should measure approximately 4’. Use the handsaw to cut the other 1” x 2” x 8’ pieces accordingly. Upon completion, drill pilot holes into each piece of wood being used to reinforce the frame, at about one foot intervals, starting roughly 2” from the ends of the frame. Next, fasten every piece to the frame using 1 ¼” wood screws.

~ Step Three ~

Prior to placing your raised bed frame in the desired location, an important step is to weatherproof the frame, for longevity, using weatherproofing such as Thompsons Water Seal. Even though the wood we used is already treated to control for such things as insects (i.e. termites) and weather (i.e. rain/water), it is helpful to add extra protection to the frame.

Following the placement of your raised bed, or even prior to its placement, you must prepare the growing medium. As such, using the basic volume formula of length x width x height (V = lwh), I was able to determine that I needed approximately 27.78 cu ft of material to fill the bed.

Volume (v) = Length (l) x Width (w) x Height (h) = 8.33’ x 4.00’ x 10.00” = 27.78 cu ft

Volume (v) = (Length (l) x Width (w) x Height (h)) / 1 cubic foot = (99.96” x 48.00” x 10.00”) / (12” x 12” x 12”) = 47,980.8 / 1,728 = 27.78 cu ft

As such, I started with a base of compost on top of a few cubic feet of newspaper, which serves as compost upon decomposition while also preventing weed growth. The main body of compost consisted of a few cubic feet of lawn clippings/trimmings (e.g. grass, leaves, weeds) and leaves that had been decomposing over the course of the winter season. Next, I filled the rest of the bed with Garden Pro Topsoil, Scotts Premium Topsoil, Miracle-Gro Garden Soil, and Premier Sphagnum Peat Moss. In the end, the raised bed was filled with a total of 26.00 cu ft of material and was comprised of the following parts of growing medium:

Scotts Premium Topsoil x3 (0.75 cu ft x 3 = 2.25 cu ft)
Garden Pro Topsoil x21 (0.75 cu ft x 21 = 15.75 cu ft)
Premier Sphagnum Peat Moss x1 (3.00 cu ft x 1 = 3.00 cu ft)
Miracle-Gro Garden Soil x1 (1.00 cu ft x 1 = 1.00 cu ft)
Compost (e.g. Grass, Leaves, Newspaper) (4.00 cu ft)

Total: 26.00 cu ft

~ Step Four ~

Since my yard is not protected by a fence, I decided to build a custom PVC structure which would support a protective net placed around my garden. After having an issue with the structural integrity of 10’ PVC being bent into a hoop house with only 3’ 8” of space between the long sides of the raised bed, I had to revise my original plans and instead build a rectangular structure. For this part of the project, you’ll need the following tools/supplies:

Since I was working with 10’ pieces of PVC, I decided to cut two in half and go with a roughly 5’ tall structure. Therefore, I took two pieces of the 10’ PVC, marked out 5’ on each piece, scored the spot all the way around with the MAGBIT Tube Cutter, and then used a DeWALT 5-in-1 Hacksaw to finish the job. With the four 5’ pieces of PVC ready to go, I placed them in the raised bed and used their positions in each corner to measure out the connecting pieces. As such, I cut down the three remaining pieces in order to obtain two 7’ 10” pieces and two 3’ 6” pieces. With all the components prepared, I connected the PVC structure using LASCO ¾” SCH40 Side Out Elbow. Between the weight of the structure and the packed dirt at the base of each corner, I shouldn’t have any problems with the PVC structure moving/blowing away. Finally, using a cut down Easy Gardener 14’ x 14’ Mesh Netting, some scrap wood, such as leftovers of the 1” x 2” x 8’ pieces of lumber, and the spring clamps, you can secure a net around the raised bed to protect it from animals. For access to my particular raised bed garden, I cut a slit down the middle of the “front” of the raised bed, used some duct tape to make the flaps attractive, and closed it with some releasable zip ties.

Here is the finished product:

Accounting of Custom Raised Bed Costs

The following list details the cost of the additional tools/supplies I needed to construct the raised bed and PVC structure. The below cost does not include the original amounts spent purchasing tools such as the circular saw or tube cutter which were bought previously for other projects. As such, please see below for the rough cost estimates (some items were bought on sale/discount):