Building an Inground Bog Garden


Back when I was fresh into this hobby of mine, I built my first inground bog garden. I wanted to incorporate a water feature and decided to go with a small fish pond and waterfall.  I am very pleased with how it turned out and I hope you find these steps on building it useful.  Enjoy!

Step one of course in knowing how you want your bog to look. It's important to plan ahead and draw out your design.  Think about what plants you want.  If you only have access to one side of you garden, put your taller plants toward the back and smaller plants up front so you can see everything well.  Also, think about which direction the sun hits your garden.  Tall plants can cast shade on smaller plants and hinder their growth. I'm located in Tennessee, so the sun always comes from the south throughout the day.  The north side of my garden happened to be against my back porch, so that is where I put my tallest plants.  Once you have a general idea of what you want, you can begin gathering materials and construction.

Digging out the bog

Digging out the hole for my bog was the most physically demanding part of this project. I had to dig a fairly large pit, mainly because the pond liner was so large ( I believe it's a 150 gallon pond) and the deepest point is at least 2 feet deep.  Once the pond was roughly dug into position, I continued to dig out the area surrounding it for my bog garden.   In general, I gave myself between 12 to 24 inches of surrounding area for my plants, so this area I kept 6 to 12 inches deep. Once I was happy with the shape and depth, I moved on to the next step.

Prepping the underlayment and filling

Lining the bog with plastic ensures that moisture stays in and minerals from surrounding soil stays out. But there's other things that need to stay out as well and that's varmints, like moles and voles.  To protect the bog from these furry little troublemakers, I used hardware cloth, or rust resistant metal screen, to line the bottom and sides of the bog.  Using spikes to hold the hardware cloth in place, I then began to line the entire hole with 6 mil plastic.

Some holes are needed to allow slow drainage of large doses of water. Without drainage, the entire hole could fill with water and less dense materials, like perlite and unsaturated peat, could float and overflow out of the bog.  I just used my pocket knife to cut several 3 inch long slits in the bottom of the plastic lining. Once the plastic was fitted to my liking, I spread some sand in the bottom of my hole to create a solid, level base.  I used play sand with no issues, but I've heard that pool filter sand is much cleaner and less likely to harm CP's.  

I laid the pond liner in place and filled in all the deeper crevices with sand, but only up to the top of the lower tier.  I figured I would be stepping on the tier to do maintenance and wanted a good firm support below the liner to prevent it from cracking.  Once the lower section was filled with sand, I began mixing soil to fill in the rest of my bog for my CP's to grow.  I used my wheelbarrow to do the mixing.  

Mixing soil for a bog garden doesn't have to be difficult. I've mixed different concoctions using peat and sand, peat and perlite, or all three. For my bog, I used sphagnum peat moss and play sand, at a ratio of 60:40_ish.  To be exact, I mixed one 3 cu.ft. bale of peat to two 50lb bags of sand.  My wheelbarrow wasn't big enough to mix a whole bale of peat at once, so I did half at a time.  While mixing, I wet the mixture with water to ensure the bog was good and damp for my plants.  I don't like using city water, but in this situation I didn't have enough water in my rain barrel to mix all this soil.  

I had to take several breaks during the filling process...wet peat and sand is pretty heavy stuff (I was sore for days after this project).  After finally getting the hole all filled in, I set the upper pond liner in place that would become the waterfall feature of my garden.  I had a lot of river rocks on hand, so I used them for edging and building up the waterfall.  After I was happy with how everything looked, I began working on my favorite part...PLANTING PLANTS!

Planting the Plants

I got really luck obtaining a bunch of plants for my garden. I had a few sarracenia in my collection to plant, but nowhere near enough to fill all this new space.  I found a seller on Ebay that was thinning out his garden and selling a large lot of random sarracenia divisions. When they arrived I was surrprised to find about 32 plants in the package! I didn't know what variety the pitcher plants were, so I just went with it and spread them out as evenly as I could and the west side of my bog.  I had some S. Titan plants that are known to get about 3 feet tall, so those went in the back of by bog, on the north side.  My smaller plants, like S. purpurea, flytraps, and sundews, went on the front, south side of my bog.

Of course, all the planting wasn't done on this one day.  I've added and moved plants several times, and I also have about a dozen goldfish happily living in the pond.  The final picture below is how the bog looks today.  I'd still like to make some improvements to the bog, like a automatic watering system and some nice night lights, but those will come in time.