The bog in the pictures is in Portland, Oregon, where we can grow Trumpet Pitcher plants (Sarracenia) of all species, Cobra Lillies (Darlingtonia Californica), Venus Flytraps (Dionaea Muscipula), and Sundew (Drosera)and Butterwort (Pinguicula) species that require a dormancy period.
If you live in an area where the weather is more tropical, you could also grow tropical Sundews, Butterworts, or any other carnivorous plants that grow well in your region.
Step 1: Gather the Materials:
The next item is some plastic sheeting. I used 4 mil black plastic. Generally speaking, the thicker the plastic the better, but it's not critical. If possible, get a roll that will allow you to cover the top and the bottom of the pool in a single piece.
Next, you'll need enough potting medium to fill the pool. For my bog, I used peat moss and perlite in a 50/50 mix. The big bale of peat and the big bag of perlite just about did it. If you have another preferred potting medium, feel free to use it.
Next, you'll need a drip-type soaker hose. The one that I found was 25 feet (8m) long. For this size pool that's about the longest that will easily fit.
Step 2: Make a Hole:
Next, dig a round hole a little bit larger in diameter than your pool. Ideally, you'd like a space of about 3-5 inches (8-12cm) around the outside of the pool. This makes it harder for pests to climb in, and gives you a place to stuff the excess plastic that will be left over at the end. The depth of the hole is up to you. Deeper means more insulation, but shallower means that pests and weeds will have a harder time getting in. Too shallow, and the pool will see greater wear, both from the weight of the full bog (The sides of a deeper hole will help support the sides of the pool), and from greater exposure to sunlight, which will make the plastic brittle. I dug about two thirds the height of the pool, and it was about right.
Next, fold the rest of the plastic sheet over the top of the pool. At this point, the pool should be loosely, but completely covered with the plastic. The top layer will form the floor of the bog.
Step 3: Create an Eco-support System:
There will most likely be some excess plastic over the edges of the pool. tuck this down around the edges of the pool, and if possible, slightly underneath. This will help to keep things neat and tight.
Now take your soaker hose and set it on top of your potting medium in a spiral-shape. Make sure the feed end of the hose is on the edge of the pool. Try to keep the space between the loops as even as possible, and be careful not to crowd the space your plants will soon be in.
Once you've got the hose where you want it, cover it with more potting medium. Ideally, the surface of the medium should be higher in the middle, with a gentle slope down to the edges.
Hook up the soaker hose to your water supply, and you're ready to go! I recommend initially running the water until you see puddles forming on the top of the medium, so you know there is plenty of water in the bog, and that the peat is pretty well saturated. After the bog is established, run the hose just enough to keep the medium moist. I find 10 to 20 minutes of soaking per day is enough in the summer, and in the spring and fall I rarely worry about it at all, since we do get a good bit of rain.
Your plants' new home is now ready! Transplant your carnivores and enjoy! The picture of the completed bog is how I originally planted it in 2003. Within a couple of years it was a field of Trumpet Pitchers. The amount of growing room in the bog, the amount of insects they were able to catch by being grown outdoors, and the natural passage of the seasons just set them off. The side yard where this bog was built is getting re-landscaped, so watch for another instructable about building raised CP bogs into a patio!