Gardening over a septic system leach field presents unique challenges, but we’ve found a simple and effective solution. Instead of planting directly on the field or using a traditional raised bed, we repurposed 55-gallon juice drums to create an elevated garden. This method not only protects the integrity of the leach field but also makes gardening easier on the back.
Why This Plan Works
- Protects the Leach Field: Keeps plant roots away from sensitive septic components.
- Utilizes Repurposed Materials: Upcycled 55-gallon drums reduce waste.
- Ergonomic Benefits: Raised design eliminates excessive bending.
- Versatile and Expandable: Can be adapted for different garden sizes and plant varieties.
What You Will Need
- (3) 55-gallon juice drums (cut in half lengthwise)
- (4) support assemblies (made from 4×6 pressure-treated lumber)
- 2×4 pressure-treated lumber (for cross members and stringers)
- Construction adhesive and screws
- Table saw, circular saw, chisel, hammer, drill
- Measuring tape and string line
How to Build an Elevated Garden Over a Septic Leach Field
Step 1: Assemble the Support Structures
To begin, we constructed four identical support assemblies. Each assembly consists of:
- Two 4×6 pressure-treated legs (26-1/4″ high)
- Two 2×4 cross members (connected via dadoes cut into the legs)
Creating the Dadoes:
- Lay out dado locations on the legs.
- Use a table saw set to a 1-1/2” blade height and make a series of kerf cuts.
- Remove excess material with a chisel and hammer to ensure a snug fit for the 2×4 cross members.
Once the dadoes are cut, attach the 2×4 cross members using construction adhesive and screws. For added stability, we included a small wood piece on each assembly to straddle the longitudinal 2×4 stringer that will later support the drums.
Step 2: Connect the Assemblies with Stringers
- Position the first support assembly and temporarily stake it to the ground.
- Use a string line to mark the placement of the last assembly, ensuring correct alignment.
- Place the intermediate assemblies, level them, and attach a 2×4 stringer along the top of the legs.
- Secure another 2×4 stringer into the straddles on the cross members.
- Avoid using construction adhesive on this step to allow for future adjustments or relocation.
Step 3: Secure the Drum Holders
To prevent the drums from rolling, we installed 2′ sections of 2×4 along the inside edges of the top stringers.
- Measure and mark the midpoint for each drum placement.
- Align a 2′ section of 2×4 with each mark and secure it with two screws.
Step 4: Prepare and Install the Drums
- Carefully mark cutting lines on the drums.
- Use a circular saw with a sharp carbide-tipped blade to cut them in half lengthwise.
- Wash the drums thoroughly before positioning them in the framework.
- Drill a few drainage holes slightly off-center (to avoid interference with the 2×4 stringer below).
- Fill the drums with soil, and your elevated garden is ready for planting!
Note: If you’re planning to grow climbing plants, the 2×4 stringers provide an excellent base for attaching trellises.
Additional Features and Adaptations
- Expandable Design: After initial success, we built another version using a 7′ long, 24″ diameter plastic culvert.
- Planter Box Addition: A salvaged pallet was repurposed into a planter box at one end.
- Customizable Trellis Options: The frame allows for easy trellis attachment for climbing plants.
- Experimenting with Crops: This setup works well for various vegetables and herbs.
Summary
Creating an elevated garden over a septic leach field is an innovative way to make use of space while protecting the system. This raised garden bed using repurposed 55-gallon juice drums is ergonomic, adaptable, and ideal for vegetable gardening. With minimal materials and effort, you can build a durable structure that supports healthy plant growth without disturbing your septic system.
This plan is a contribution by [RushFan]. Project Via Instructables – Get the PDF Instructions here.