In May of 2011 the F5 Joplin Tornado cut its path across Joplin just 2 miles south of Hawk Hill and the weeks that followed are just a blur of emotion and the bustle of days spent volunteering and nights of every bed and sofa at Hawk Hill filled with volunteers. When the dust settled, literally, and the supply distribution center I helped organize at my church dwindled, I was ready to get my hands dirty and create something peaceful and beautiful in my space. This project was constructed in 2011- unfortunately, before I adopted the habit of taking photos mid-way through my projects, but I’ve attempted to explain the process here in detail.
The pond I built was very easy and very cheap- surprising even me at how easily it came together, with absolutely no digging involved!
Step 1. Build a strong “Raised Bed”
First, create an above ground framework for the pond by constructing a basic raised garden bed. Use pressure treated lumber and raised bed corner brackets. There are a hundred different options for raised bed corners brackets, just make sure to use a strong set that will support the outward pressure of water and your desired height. My framework was created by stacking 2×6’s.
Leveling your raised bed isn’t actually a requirement, but if you want a waterline that is level on each side, you’ll need to pay attention to high and low edges. You may need to dig just a bit to settle the boards on one side lower, or use bricks or shims to lift a low edge.
Step 2. Acquire Liner and Pre-Fill:
Next, you’ll need to find something to use as a pond liner. Commercial liners are easy to find, but I purchased a used advertising billboard tarp for my pond liner. Advertising tarps are black and unprinted on the back, UV stabilized, extremely durable, and even with shipping are a fraction of the cost of a pond liner.
Spread your liner over your raised bed, with at least 3ft of material overlapping over each side, and use a hose to go ahead and fill the pond about 1/3rd of the way- or as much water as needed to fully weight your tarp down into the framework you built. Stay nearby while filling and as the liner fills, manipulate the liner to help it sink evenly and neatly to the bottom- you’ll need to create some folds to make the liner accommodate the sharp corners of this pond design and this is easiest done with only as much water in the pond as absolutely necessary to weight the liner.
Step 3. Fill and Level Pond:
Continue filling and let the water level check how well you leveled your sides. Use rocks or boards to lift corners or sides, or shims to make slight corrections.
Step 4. Finishing Sides:
At this point, you’ll have a functional pond that looks a little more like a redneck kiddie pool than a relaxing water garden! Never fear, the next step makes a enormous difference:
I recommend doing this step with the pond filled completely- although you’ll probably get a bit wet, the result of finishing the edges with the liner fully weighted (as it will be when it is in use) is the best way to ensure the longevity of your liner and sides.
- With the pond filled completely, go around the perimeter of your pond, cutting the liner like a pie crust- letting it drape over the edges. Leave about 6″ hanging down the outside of the pond. This step just neatens things up enough to make the next steps easier.
- Pre-drill holes in the treated furring strips and place over the top of the first 2×6, pull the tarp taunt on the outside and then use a cordless drill and corrosion resistant screws to screw the furring strip down, pinning the tarp between the furring strip and the 2×6″ retaining wall. Screw through the tarp- and add 1 screw every 12″ to securely hold the tarp edges in place. (Note: Using a small cordless drill in or around water is not an electric shock risk, but NEVER use a corded drill while standing in or around your pond!)
- Continue around the sides of your pond, taking care at corners to fold and tuck excess tarp material.
- Once the trim is added on each side, use a sharp knife to carefully cut off any tarp showing on the outside of your pond.
Once the sides are finished you have a complete, ready to use garden pond for only the cost of lumber and a tarp! You can create an endless assortment of water features by adding pumps, troughs, and raised portions to your pond.
Maintaining an Above Ground Pond:
Maintaining an above ground pond in the winter can be a challenge. You may choose to drain your pond- although if your pond supports fish you may want to try and keep your pond partially thawed all winter. An above ground pond will freeze more quickly in the winter, however in zone 6 I have successfully overwintered goldfish even in exceptionally cold winters with sustained temperatures below 10 degrees F by keeping water circulating with a pump and by providing significant insulation in the form of a filled 100 gallon trough sitting on cinder blocks in the water. The combination of insulation and moving water has produced hardy fish that thrive. You may wish to purchase a commercial pond-deicer which will maintain your pond at just-below freezing.
Edible Gardening in a Water Garden: Growing Watercress
It’s easy to turn a backyard water feature into a productive element in a vegetable garden. I’ve had success growing strawberries in a floating planter, growing chickweed around my pond, and particularly in growing watercress in my water feature. Watercress grows best in cool moving water and needs no soil- in fact, the copious and thick root system works as an effective natural water filter when grown in a garden pond (but, unlike other aggressively growing water plants, watercress will die back fully in the heat of the summer- requiring little to no maintenance controlling it)
To grow watercress in your garden’s water feature, you can buy starts at the grocery store or farmers market. (You do want to be careful to be sure and purchase true watercress, though, not “upland watercress” which has a very different growing pattern and won’t thrive in a water feature) Once you have shoots of watercress, you can easily root the shoots in your water feature by securing the shoots to a stable area so they won’t be caught in your fountain or filter. Even if the watercress doesn’t have significant roots still attached, placing the sprigs in a nutrient rich environment of moving water will ensure that rooting occurs quickly.
How to root watercress:
I use metal hardware cloth (aka cage wire) to hold my watercress in place near my pond’s waterfall without allowing the watercress to flow over the waterfall. I take the new watercress each spring and place each sprig securely through an opening in the wire mesh (without getting too preoccupied with making sure the watercress is “woven” in). Simply holding it in place for a few days will be sufficient to secure the sprigs in place until the roots begin to grow and intertwine- at which point you’ll find it difficult to remove the watercress from the hardware cloth!
When growing watercress in the early spring, it is prolific and grows in large masses far earlier in the growing season than other vegetable garden plants begin producing. Using this method, you can help your backyard garden pond contribute to growing edibles in your garden. Watercress can be harvested continuously for salads, sandwiches, and snacks from early spring into summer, providing effective, natural, and chemical free filtering for your backyard pond in the process.