Build a Bog for Carnivorous Plants in Your Backyard!




Introduction: Build a Bog for Carnivorous Plants in Your Backyard!

About: Luvz to make things!!!

Do you grow carnivorous plants outdoors?  If you live in an area where this works, then why not set them up on their own bog?  This is how they grow in the wild, so they'll feel right at home, and they'll look great.  As an added bonus, there is no easier way to care for your plants, and they'll very likely divide and propagate all by themselves!

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:

To make your bog, you'll need a few things: Starting at the bottom, you'll need a children's style wading pool.  The one in the pictures measures 6 feet across (just shy of 2 meters), and is a little over a foot deep.  You can use a smaller one of you prefer, but keep in mind that the deeper the pool, the less likely it is to freeze solid if your winters typically get that cold.

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:

The bog is now ready to be loaded with potting medium.  If you haven't already mixed it, this is a fine time to do it. Don't completely fill the pool with potting medium just yet, but stop when the level is about two inches (5cm) below where you want it to be, and flatten the top surface.

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!

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    8 Discussions


    5 years ago on Step 2

    Not sure if I understand the plastic, you say to fold it in to the kiddie pool, but then on the next page you seem to first fill with potting medium and there is no sign of it being folded in yet.
    As you have the kiddie pool, what is the added benefit of the plastic, or... if you have the plastic what is the added benefit of the kiddiepool?


    Although many temperate CP will handle freezes, I've considered (but never yet tried) doing something similar, but adding (about halfway down in the soil--or maybe underneath the "bog"?) a long, thermostatically-controlled cord (as might be used to keep water pipes or car radiators from freezing)--maybe something that kicks on if the temp gets below 40 degrees F or so. Has anyone tried this? Any reports of success, failures, warnings? -pt

    I live in Dallas, and have a koi pond. It has a bog filter that leads into a waterfall that is already established. I also use pea gravel to insure the plants as well as the soil will not wash away. I dont want to use pesticides on my veg garden, which is close to my pond for watering purposes. I've been trying to find natural ways to control insect pop. I was wondering what kind of C Ps you have, that might work well in this area. Also i wanted to know if you let them winter outside. I would like to have a couple that grow wild here in tx, since most of my bog garden plants are Tx natives and are able to winter over nicely. I've look every where, and cannot find good reliable info. I was hoping you could at least point me in the right direction. The insect pop can be overwhelming in the summer, as you most likely know. Lol...


    9 years ago on Introduction

    Perlite is definitely not good for everyone because of the salt content. Even Peter D'Amato has had problems with perlite. He believes that perlite works for some people if they flush their plants regularly which entails watering heavily each time and allowing the water to seep out of the pot.

    As paperrhino pointed out, I'd also be worried about what would happen during a heavy rain (or 3 days of it), not just what happens with the hose, but I have a feeling that a pea gravel (heavily cleaned) mulch would potentially help keep the soil in place and reduce evaporation.

    I'd also be concerned about such a large amount of stagnant water, without any way to remove it, and the smell. 

    The pool is quite large, so getting to the center for plant maintenance would be difficult without disturbing plants in between which is why 4' beds are recommended in square foot gardening.

    This might be a wait-n-see sort of project.  I'm definitely interested if you can make something so simple and large and have it work without ill effect.


    Reply 9 years ago on Introduction

    Some people have had concerns about perlite, to be sure. Personally, I switched over from silica sand over ten years ago, and have had zero negative effect on my plants. Of course, your mileage may vary. Back in 2003 when I first installed the bog, the stagnant water issue was on my mind as well. The short version is that in seven years, I've never had a problem. It turns out the peat wicks moisture to the surface very effectively, especially with the openness of the perlite mixture, so there's really very little standing water in the bottom. Since we're talking Sarracenias here, you'd want to locate this in an area that gets a good bit of sun, which is going to help the surface evaporation, which in turn will help cycle water through the medium. Your point about the width of the bog is well taken, and it does require a bit of planning to have a clear path to the center. I did build another one of these with a 4 foot pool, which was a lot easer to access, but was also more shallow and less well-insulated.


    9 years ago on Introduction

    Great tutorial! I did something similar with a half whiskey barrel and pond liner. It should be said that not all parts of the country have tap water that will work with carnivorous plants. For example, in my area (Dallas, TX), the water is too hard and causes minerals to build up in the soil, eventually killing the plants. In those areas one needs to set up a reverse osmosis filter or rain barrels (which is what I use). Also, I put a length of PVC with holes at the bottom with an access at the surface of the soil so I could siphon excess water out of the planter if I've had too much rain. Otherwise, the planter fills to the top and eventually drowns the plants.


    Reply 9 years ago on Introduction

    Paperrhino, you are SO right about hard water, it's one of the surest ways to kill CPs! The good news is that the soaker hose will still work with the gravity-inspired pressure from a 5-gallon barrel of rain water. I also found that by filling the medium up to within an inch or so of the lip of the bog, and building a reasonable crown in the middle, it drains sufficiently over the side. Great points!