Recycled Barrel Wicking Bed
What is a wicking Bed?
It's a garden irrigation system that is self contained, that supplies water through capillary action! There are no moving parts, no electricity or water pressure needed so they cannot breakdown.
Wicking Beds are a Lifesaver if you plan on traveling and are concerned about watering your plants, live in an arid climate, or just don't want to waste time and water. They have lots of advantages over normal garden beds including:
- They are water-efficient! Watering from the bottom up prevents evaporation of surface water (which occurs when you water beds from the top).
- They are self-watering! Wicking beds are an especially great system to use in community gardens because they save people from driving every day during hot weeks to water their beds. A full wicking bed should irrigate itself for about a week.
- They can be placed close to the house without risk of flooding your basement, since the water is contained in the bed. This makes wicking beds a great alternative to swales on properties with sump pumps or basement water issues.
- No evaporation means no salting of soil. If you are watering your soils from the top with hard water, you risk accumulating salts, because the water evaporates and leaves the minerals behind. Eventually your soil will struggle to support plant life.
Supplies
Materials
These can be found on Craigslist, FB marketplace or even on the side of the road. I found 4 of them for free from a professional fertilizer business. HDPE barrels won't rust, or leach into your garden soil, so they're a good option. Alternatively, you can use pond liner in a wooden container.
1" PVC Pipe & Fittings
Pipe, 90 Degree Angle, & Cap
Waterproof Outdoor Rated Silicone
This will be covered, so don't fret about the color and buy the cheapest option
Tools
- Drill & Drill Bits
- Hole Saw (or a dremel and patience)
- Jig Saw
- Crescent Wrench
- Tape Measure
- Permanent Marker
- Bungee Cord
- Scissors
Optional
- 3/4" Barbed Fitting & tubing (used to link multiple barrels together)
- Moving Dolly - I didn't end up using the ones I bought and decided to keep it stationary
Barrel Cutting
- Thoroughly rinse the outside of your barrel and allow it to airdry. Similarly, rinse the interior and drain as much as possible to prevent a mess when cutting.
- Measure the midpoint at several locations and mark with a permanent marker
- Stretch a Bungee cord along your marked points until straight. Use the cord as an edge to draw a straight line around the entire barrel
- Drill a pilot hole along the line
- Use a Jigsaw to cut along your line
Seals
Water can escape your lid! Let's seal it up. I personally used old bungs without a seal however if you purchased bungs like in the picture this may not be necessary unless you'd like the additional peace of mind.
- CLEAN - Silicone doesn't play well with dirty surfaces. Clean up the threads as best as you can
- Rough it up - Use sandpaper or wire brush to rough up the area around the interior drum near the bung hole. this will provide a good surface for the silicone to "grab" the surface of the barrel.
- Silicone it up - this will never be seen. Be sloppy, it's ok. I coated the threads on the bung, the barrel, and the whole mating surface
- Screw it up - Literally screw your bungs into the barrel
- MORE Silicone - The inside of the barrel around the bung can be completely covered. Seriously.... coat it
- Dry Time - Ensure your silicone is dry by consulting the instructions on the tube.
- Water test - After 24 hours, fill with water and check for leaks.
Overfill Drain
Installation of this component is ABSOLUTELY CRUCIAL. This bulkhead fitting is going to be the overflow port. Without it, the barrel will simply flood your plants and overflow in the rain.
- Determine your soil needs - This step is a balancing act, what is important to YOU! I want to grow tomatoes and not worry about them when I go out on business. But tomatoes should have at least 12" of depth. So, I ensured I marked 12" minimum from the top of the barrel and made sure that my reservoir components fit. If necessary downscale the diameter of your drainage pipe.
- What are you growing? How much soil depth are the roots going to require?
- How long do you want the barrel to be unattended? Less soil = Larger reservoir = More time in between refills = BUT Less growing potential
- Will everything fit? Adjust as necessary
- Mark your overflow height - This is the point in your barrel where the reservoir will be separated from your soil.
- Drill Bulkhead fitting hole - Consult the bulkhead instructions for the appropriate hole saw size. Ideally, you want to drill a hole only slightly larger than the OD threads
- Install Bulkhead Fitting - This component should have reverse threads! Follow the arrow typically embossed on the fitting.
- Optional
- Install a Barbed fitting. This will allow you to link barrels to fill multiple at the same time. Personally I wouldn't recommend this as it slows down watering and increases project cost.
- Note: If you build a chain of barrels, the final one will require a second drainage bulkhead fitting.
- Paint - This is the last time the barrel is going to be empty and easy to maneuver. I put some black paint along the top of the rim to hide that they were barrels.
Filling Hardware & Wicking Mat
This is how to fill the final product. The PVC provides a channel through the dirt to fill the reservoir without leaching the soil's nutrients away.
- Bend & Test fit - Bend your Drainage pipe to fit inside the bottom of your barrel. Make it a closed loop so stone won't intrude and reduce your water capacity.
- Measure and Cut - Cut the PVC to fit along the bottom of the barrel as well. Secondly the pipe ought to reach all the way to the top as shown
- Glue - Use PVC cement to assemble your PVC piping
- Drill - Use a drill to make several holes along the bottom of the PVC pipe
- Wrap - Cut a small section of fabric and wrap the hole you've created. This will prevent them from clogging.
- Assemble - Remove everything and assemble with bottom wicking fabric. I laid mine as an "X" across the bottom of the barrel. You may wish to tape the PVC vertically. Mine fell and is not permanently at an angle
Fill'er Up
Final Assembly
- Add Fill - IMPORTANT! Fill to the top of your overflow bulkhead fitting! Fill will provide the support for your soil.
- Use a fill of your choice but remember, we're trying to MAXIMIZE volume. Sand/ stone will work, however it takes up a lot of space. Lava rock is a porous rock that won't degrade, offers more water storage volume, and is much lighter.
- Add Fabric to segregate soil from fill - Lay fabric across the top of the drum and cut to length. Additionally, cut a hole for the PVC pipe to fit through. Line the inside of the barrel with these cut pieces.
- Add soil
- Trim - Trim your PVC pipe to whatever height you choose.
- Decorate - Decorate to your hearts content, BUT do not do anything to compromise the waterproof barrel with screws/nails...etc
- Glue stained wood plank to the side
- Paint
- Load into a salvaged crate like I did
- Water - Add Water until it begins to come out of the overflow fitting. One last check for leaks.
- PLANT! Everyone's favorite step!
Things I Would Have Changed
Upon review there were some things I would have done differently. The beds have been working well for 2 years now, so nothing mechanically went wrong, but esthetically I could have made better decisions.
- The Barrels stick out of my crate too far.
- I would have preferred to have made the crate into a larger bed using pond liner. But I needed the barrels for the depth the offered for my tomatoes.
- Secondly, the barrels limit the planting area. I should remove them and decorate them as seperate planters and build the crate into it's own wicking bed.
- The fabric sticks out of the top of the soil.
- Once the water has been wicked up into the soil, it really isn't necessary and can even cause some evaporation if exposed to the air. I should have trimmed it lower
- Climbing stakes are too high
- I added driven fence posts for climbing wire, but they are too tall and have sharp corners. I would like to modify moving forward
This is not to say that this project was not rewarding. I've had great success with tomatoes, beans and peas in these planters and would 100% build them again.