Bog Garden for Carnivorous Plants




About: Schools: Cleveland State University / Campus International School (elementary)

Nothing livens up a classroom windowsill like some predator / prey action.  Carnivorous plants are the mightiest of houseplants, but many can only thrive in a soggy, acidic, bog environment.

To keep your carnivorous plants happy year-round, make them a simulated bog environment!

You can follow the steps in this Instructable to make a copy of the bog garden shown, or adapt the same techniques to whip up your own to suit your own containers and windowsill.

Let's get started!

Carnivorous Plants

Most nurseries and garden shops carry carnivorous plants packaged in small plastic terrariums (terraria?) to keep them moist.  If you can't find any carnivorous plants for sale near you, try searching online for a supplier that will sell them by mail.

Here are some bog-loving carnivorous plants that you can grow in an indoor bog:

     -  Venus fly traps  (Dionea muscipula)
     -  Pitcher plants (from the genus Sarracenia, Nepenthes, or others)
     -  Sundews (from the genus Drosera)
     -  Butterworts (Pinguicula vulgaris.  I've never had any success with these, myself)

Additional Resources

For more information about carnivorous plants, try:

     - The book "The Savage Garden," by Peter D'Amato
     - The United States Botanic Garden's website devoted to carnivorous plants
     - The North Carolina Botanical Garden's website

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Step 1: Supplies


To replicate a soggy, acidic bog garden, you'll need four containers:

- A large, waterproof tray for the bottom (this holds excess water and protects your windowsill from any drips)

- A large pot made of unglazed clay or "terra cotta" to hold the plants themselves.  (It's important that water be able to seep through this container, as well as the next two on the list.)   Choose a container that fits your site: I used a round pot, your location might be better served by, say, a "window box" trough, or some other container.  Get creative!

- A small terra cotta pot to serve as a reservoir.  This pot holds excess water and slowly lets it percolate into the soil, keeping the bog nice and damp.  (For a tip on choosing the size of this container, see step 3.)

- A small terra cotta saucer to elevate the reservoir pot. 

For the planter shown in this project, I used the following:

- A 10-inch-wide plastic tray (with no holes in the bottom)

- A clay pot, 8 inches wide and 4 inches deep.

- A small clay pot, 3 inches wide and 4 inches deep

- A small clay saucer, about 4 inches wide (which was sold to match the small clay pot above)


To assemble the planter, you'll need a sturdy, waterproof adhesive that can join ceramics together.  I've had good results with both of the following:

- 100% silicone aquarium sealant (this adhesive smells a bit like vinegar at first, but is completely odorless once it solidifies)
-  Expanding-foam glue (this glue forms a much stronger bond, but it will also swell to several times its original volume, which might not fit in with your plans)

Soil Ingredients

To replicate a bog environment for the carnivorous plants, we'll be using a mixture of:

     -  2 parts peat moss
     -  1 part sand  (play sand borrowed from the sandbox is perfect)
     -  1 part sphagnum moss or "decorator's moss"

You'll need enough of this soil mixture to fill your large pot.

(Garden shops tend to only sell these materials in much larger quantities than you'll need for this project.  However, every garden shop has a pile of broken, leaky bags somewhere.  If you ask the shopkeepers very nicely, they'll usually let you have a small amount of this waste material for a reduced price.  Better yet, get the most adorable second-grader you can find to do your asking for you;  explain that it's for a school project, and you just might come out of this with some free dirt.)

Step 2: Make the Reservoir

Start by flipping the small, "reservoir" pot upside-down.  Apply a bead of glue around the edge of the pot's bottom.  Set the small saucer on top of the glued surface.  Leave the pot and saucer together, bottom-to-bottom, until the glue dries.

Step 3: Test-fit the Pots

Once the saucer and reservoir pot are glued together, flip the pair over and place it (with the saucer-side down) inside the larger pot. 

Check to make sure that the top edge of the reservoir pot sticks up above the top rim of the larger pot.  This ensures that your reservoir pot can be filled with water without overflowing into the soil.  (It's a good idea to try this "test fit" with your containers when you're choosing which to use for your project.)

Once you're satisfied with the fit, flip the reservoir/saucer pair over and apply glue around the edge of the saucer.  Then, flip the pair over and press the glued saucer rim to bottom of the large pot.  Wait until the glue dries.

Your pot assembly is complete!

Step 4: Populate Your Bog

Make Your Soil

Mix two parts peat moss, one part sand, and one part sphagnum (or decorator's) moss in a big bucket or similar container.  Add water to the soil mixture until it's damp, but not muddy.  Give it another good stir to make sure that the peat moss is soaking up the water.  (This is the fun part.) 

Place your three glued-together pots into the large plastic tray to contain any future messiness.  Fill the outer portion of your bog garden with damp soil, but try to keep the soil out of the central reservoir pot.

Add Your Plants

Carefully remove your carnivorous plants from their original containers.  (Growers often package carnivorous plants with little polystyrene "skirts" around the base of the plants to help keep the soil damp.  I find it's best to use scissors to carefully snip these into several pieces, then gently pull them away from the plants.) 

Take note of the soil that your carnivorous plants came potted in;  growers often place carnivorous plants in pure peat or sphagnum moss.  Notice how damp it was?  Our goal in making the bog garden is to help the plants stay in soil that's this moist.

Make a small hole in your pot's soil for each plant, then carefully place it inside and tamp the soil down.

When all your plants are in the soil, use extra sphagnum (or decorator's) moss to cover the soil between the plants.  The extra layer of moss on top will help keep the soil from drying out.  (If you'd like, you could also use small pieces of moss you've collected from your sidewalk or the shady side of your school building.)

Add Water

Fill the central reservoir with water, and add a little extra water to the plants themselves until you start to see a trickle of water coming out the bottom of the pots into the plastic tray.

To keep your plants soggy and happy, refill the reservoir whenever the water level drops.

All of the books suggest that you use rain water or distilled water for your bog plants;  they don't like the minerals that are in tap water or bottled water.  (I keep a jug of rain water next to the bog garden, just for this purpose.)  However, if you have to choose between letting your plants dry out or watering them with tap water, go ahead and water your plants with whatever's available.   They'll thank you for it.

Best of luck with your bog garden!  If you have any advice, or a creative new design, please use the comments to share your ideas with the group!

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46 Discussions


1 year ago

Nice idea, terracotta pots however will leach minerals into the soil that will eventually kill the plants. I would suggest changing to something plastic and use holes or a permeable membrane. Also during the summer the plants are happier outside


3 years ago

This is really cool! nice instructions. Where can I get a carnivorous plant that eats pigeons?? If anyone out there is addicted to succulents, like I am, they often come in a glass container with s this kind of moss all around. This set up is no good for the succulents which have to be repotted so they have good drainage, but it does mean I have some spare moss to give this a go!!! :) Maybe a bog in glass would be good. The ultimate would be to create some kind of Jack Spratt setup where desert and bog exist side by side in perfect synergy so they all stay happy with intermittent attention to maintain their respective Utopia ;)


4 years ago on Introduction

Very good idea!

I made it recently. It's awesome to have bog garden inside ;)

I have populated my bog with:

Dionaea Muscipula, Drosera Madagascariensis and Sarracenia Leucophylla.

They are growing vigorously in the mix of sphagnum peat and perlite.

I have also a hint to the butterwort fans (problems are also mentioned in guide). Cultivation varies between species but generally:

1. Most plants from Pinguicula genus need more water than other carnivorous plants (you can overhead water them from time to time).

2. All temperate and warm-temperate P. species like chilly (or even cold) water in summer. Don't be afraid of thermic shock, butterworts are adapted to that.

3. Temperate species are very hard to keep alive on windowsill. It is much easier to cultivate mexican species.

4. Never use raw sphagnum for your butterworts! They are growing healthier in peat-perlite, peat-sand or even peat-perlite-sand mixes.

1 reply

Reply 4 years ago on Introduction

Howdy, Achmes:

Wow, thanks for the advice! I'll have to try the peat-perlite-sand soil with a butterwort plant this summer.

(I WONDERED what we were doing to kill all those butterworts. Those poor, poor butterworts...)

Howdy, enthusiastic_gardener:

I find that I have to refill the central "reservoir" pot every three days or so. (Once you make the garden the first time, the water level reaches an equilibrium point pretty quickly.)

I haven't made this yet but we are planning to make it. As I understand it both the reservoir in the middle as well as the main pot for the plants needs to be able to let water seep through so that you get the right level of waterlogging. So no, for the reservoir pot and main pot you need to have a porous pot, and terra cotta pots are generally the most available.

Hi, heyitsmeronilo and flammaefata!

You got it, flammaefata! The unglazed, terra cotta pots are the key to letting water gradually seep though. (Only the bottom tray is made of plastic, and it's mostly there to prevent a mess on the windowsill.)

I've seen plastic pots that look like they're made of Swiss Cheese -- they're perforated with dozens of tiny holes. (I think they're intended for orchids or some manner of epiphyte. Or maybe they're prank drinking cups?) I wonder if that kind of plastic pot might work in a bog garden? I've never tried it...

Quick question for you, if you don't mind, sir. Why adhere the reservoir pot and base together? Wouldn't the packing of the moss/sand in addition to the weight of the water be enough to hold the reservoir down/in place?

2 replies

Hi, Spencer!

(Sorry about the delay in replying!)

I mainly glued the pots together to block the large holes in the bottoms of the "reservoir" and main pots; the goal was to slow down the leaks. However, if you found clay pots with no holes in the bottoms, I don't see why you'd need to glue anything together.


5 years ago on Introduction

I've been looking at various ways of setting up a mini pond; complete with small fish and plants. I've had one that was pretty successful - but the soil muddied my water so bad you can't see the fish (doesn't seem to bother them in the slightest!)

I really like this idea - but would I be right in thinking that the nitrates from my fish water would NOT be able to seep though the pot, that it would only be the water?

2 replies

The nitrates excreted by fish are in the form of ammonia and is water soluble. Therefore they will be carried by the water and seep into the ground with it, where they'll disassociate and be bound/taken up by the ground/plant roots. The nitrate concentration in aquarium water is also quite low (if your fish are still surviving, high concentrations are attained if you don't have proper biological filtering) so it won't give your plants a "fertilizer burn". This is why it's such a good idea to use aquarium water to fertilize plants, and why some people are using hydroponic set ups connected to aquariums to grow their plants.

Hi, tbernstetter and flammaefata!

This sounds like a fun-to-watch project. Are there aquarium-able fish that prefer an acidic environment? (My Big Book Of Bogs says that real bogs tend to be low-oxygen environments, which doesn't make a terrific home for fish.)

Also, is "aquariumable" a proper word?


5 years ago on Step 4

Carnivorous plants like acid so distilled water is OK too. Distilled water has a ph around 6, I believe.

3 replies

Hey, luckylulujoe:

Allright, now you've got me curious. I'm going to have to determine the pH of the bog garden's soil, AND of the distilled water and rain water.

(And by "I" I do, of course, mean "the students." I only got into teaching so that I could indolently drink coffee while somebody else does all of the measurements.)


Reply 5 years ago on Step 4

Mmm coffee! Please post their results. I'm a sucker for the Flytraps available in the spring at the plant stores here, so I'm definitely going to make one of these.
 Tears aco I was taken to an actual bog by rangers in the Pine Barrens in NJ. Lots of sundews and butterworts surrounding a 3x3 puddle of water in the middle of pines. Would have walked right over it without guidance. Lots were in bloom, too.


Sounds like a neat trip! (I've never seen Venus Fly Traps in the wild. Maybe we need to install a bog in my neighborhood. Then install some mastodons.)