Building the Raised Beds

I have a dog. A large dog. And the one thing I'm not interested in (okay, one of many things) is my dog lifting his leg on my lettuce crop. No! Bad Dog! And that, dear reader, is why I've opted for a raised bed that is higher than my dog can lift his leg. Well, that and saving water and providing a better soil than what I have on this hillside and saving my back and knees from having to bend over to garden on the ground. So maybe I shouldn't entirely blame the beast that shall not be named. (But if you ever find yourself in my dining room, note that my vegetables are organic and wiz-free.)

I did a lot of research on raised beds and I've had such good luck with tomato grow boxes with self-watering reservoirs in other places that I thought I'd give that a try here on a larger scale. This cool guy that goes by the name "Albo Pepper" over on YouTube recommended a specific design for a sub-irrigated planter (SIP) that made sense and was easy to assemble. So, I followed his lead and built two of them 3x8(ish) feet. I've got a fence on the Northwest side of the yard that gets good sunlight most of the day so that's where they went. The fence blocks wind and provides an easy surface to attach trellises for support.

You can find Albo Pepper here: albopepper.com I recommend his YouTube channel if, like me, you're both a nerd and a gardener.

So I built a redwood box from lumber I got at our local hardware store. I bought an HDPE tarp (don't use PVC as it leaches BPA) and stapled it into the bed with large hardware staples. I bought a large role of 4" perforated french drain pipe which will act as the water reservoir and air gap. Notice how the pipes are all bent from being wound in to circle for a long time? Yeah, that was annoying. [If you run a 2x4 through the pipe and let it sit in the sun, that'll straighten in out.]







Next, grab some standard landscape cloth and duct tape and make a simple cap for each end to keep the potting mix out of the pipe.








Here I've used the heavy bale of peat moss to weigh the pipes down in the sun and try to get them to straighten out a bit. It sorta worked. The 2x4 method worked much better.

Notice the pattern with the pipe ad the head here and there's another pipe just like it at the foot. The header pipe here will get a water feeding tube dropped into it and the footer pipe will get the drain. Water flows into the reservoir here. It doesn't directly connect to the footer for easy draining, which is a good thing. You want the water to come into contact with the potting mix as it percolates through the bed.





Here's a view of the footer where the drain will go. Notice the gap between the pipes? This gap will get peat moss shoved into it and will act as the wick which will pull water up into the bed.



And here you can see the peat moss is in (I've exposed pipe for the picture) and I've started dumping the soilless potting mix into the bed.

Note that not pictured is the 1" PVC drain pipe that punctures the wood framing and tarp and goes into the top of the footer pipe. This drain keeps the water from flooding the bed and it lets air exchange. Air is critical to healthy plants.


Here we have a full bed. If you look in the upper right corner, you'll see a few inches of PVC pipe sticking up. This is the feeding tube for the water reservoir. It's wide enough to stick a hose into, though I'll likely insert a high gallon-per-hour drip tube in the to reduce the amount of manual maintenance required to water the plants. You can also build a funnel out of a two liter soda bottle and that's great for dumping your shower warm-up water into the bed to save potable water. This is California, after all. Water can get scarce.

If you use grey water to water this bed, never plant root crops. No carrots, beets, potatoes, or anything like it. Grey water should never touch the part of the plant you eat. I'll stick with potable water here because I love root crops and use my grey water on the fruit trees and ornamentals.


If you're going to use the square foot gardening method, which I highly recommend, now is the time to drop down your grid. I chose to use brightly colored cording because it was easier to work with than a wood grid. I'll need to reset it when I put the cap on the bed, but I couldn't wait to plant and needed the grid for that.



I cheated and bought two frames from the hardware store to make a trellis for my sugar snap peas. The garden is ready for plants.






One down... one more to go.