How to Build a Pitcher Plant Bog
This technique was designed and perfected by the Atlanta Botanical Garden. We would like to give a special thanks to Ron Determann at the Atlanta Botanical Garden for allowing us to reprint this article on our website. Be sure to visit ABG to view their fantastic conservation work with endangered native plants.
- Pond liner or roofing liner, at least 9' x 11' (for a 5' x 7' bog)
- River sand, approx. 1 1/4 ton (carpenter's sand is ok, don't use granite sand or playbox sand)
- Peat moss, 3 cubes (milled sphagnum moss, found at local nursery)
- Small rocks (pebbles)
- Large rocks or logs
- Place to dump red clay
- Soaker hose with a stop block and a quick connect (Home Depot or Lowe's)
- Garden hose
- Measuring tape
- Wheel barrel
- Camera with film
- Machete or saw to cut roots if bog is near trees
- Rubber boots and dust masks are a plus
Step 1: Choosing the Site of Your Pitcher Plant Bog - Sun, Slope, Safety, and Water
Pitcher plant bogs require full sun. Western sunlight, the more intense of the day, is especially important for good growth. Choose a site which gets at least direct sun to the ground (not filtered through trees) in the afternoon. Choose a site with the slightest slope if possible (one inch slope per three feet or less is ideal). If your land is flat, you can create an artificial slope when you dig the hole. Do not choose a site that has a steep slope! We are looking for slight gradation. We want water to flowthrough the bog, top to bottom, slowly, not rush through like a waterfall. Choose a safe site for your bog. You don't want a site in the middle of a regularly used foot path where people will walk through the bog. You don't want chemicals to wash into your bog after it rains. Bogs are very sensitive to chemicals (fertilizer, herbicides, pesticides, parking lot oil and grease runoff). Right after it rains, go outside and see where the rainwater is washing. You don't want your bog to be in the path of this wash trail. Locate your bog near a water source (faucet). You may need to run a connecting garden hose from your water source to your bog. You need to be able to turn the water on and off again as needed (about 30 minutes of water a day in the spring and summer). You will be watering the bog with your soaker hose (again, little amounts of water flowing slowly through the bog).
Step 2: Digging the Hole
Design your bog on paper. Lay your garden hose on the ground or spray ground with spray paint to mark this shape on the ground. Peanut shapes work well with the head of the peanut smaller than the bottom. Simple shapes are usually better (don't recreate the map of the Brazil or China!). Dig a hole 5 x 7 feet wide and 18" deep. The sides should be gently sloping so the pond liner can easily lay over it. Carry the excess dirt away from the bog for use elsewhere on your school site. Identify the high end and low end of your hole. If your site has a slope, this will be obvious to you. If your site does not have a slope and you are going to create one inside your bog, let the high end be closest to your faucet. The high end is called the source. That is where the soaker hose is buried for watering your bog. The low end is the sink. This is where the run-off water will go. Again, if your land slopes naturally, this will be determined for you. If your land is flat, let the source be nearest to your water faucet so you don't have garden hoses snaking around and laying all about your garden. Water will flow through your bog, watering from one end (source) and running off the other (sink). The bog must be 18" deep. Shape the bottom of the hole according to your source and sink directions (higher on the source end, lower on the sink end). You want to create a slight slope along the bottom of your hole (helps with drainage). Step back a few feet, kneeling to get a good view of the whole scene. You want the source end to be ever so slightly higher than the sink end. If your site has an up slope, you can follow the lay of the land. If your site is flat, fill the source end with a shovel full or two of soil and pat this down evenly so that it is just higher than the sink end. Here's how to check your slope: trickle water from a garden hose onto the source end of your bog. The water should run (at a trickle pace) to the sink end of your bog. The water may pool a bit at the sink end, but this is okay as long as the drop from source to sink is slight. The sink end of your bog will always be wetter than the source end. Remove all rock, sticks, roots, or any other sharp objects from the hole. Make the bottom and sides as smooth as possible. Pat smooth with hands.
Step 3: Laying the Liner
Now that you have a big hole in the ground, you can lay the liner in it. Keep it folded or rolled and lay the roll across the hole. Unfold the liner, centering it in the bottom of the bog. Make sure the liner covers the entire hole evenly. You don't want 4 extra feet of material on one side and 1 foot on the other. Push the liner down flat to the bottom of the hole with your hands, contacting earth all around. The liner should lay flat against the bottom and all the sides. Lay the liner as flat and smooth as possible. Some folds are inevitable, just smooth and fold them neatly. Remember that garden tools and sticks can poke holes in the liner so don't move the liner about with tools. Use your hands. There should be extra liner laying all the way around the top of the bog. You want to maintain at least a 12 inch lip around the top of the bog. This can be cut and removed later, but do not cut it now! The extra material is needed for securing your liner with rocks and sand.
Step 4: Filling the Bog with Sand
Fill the bottom of the bog with 12" of river sand (fill to 6" from the top of the hole). Do not use granite sand or playbox sand. Granite sand can only be used if it has sat out in the rain for a year leaching the chemicals from it. Playbox sand is too fine. You want a course sand. Water the sand. Soak it with a garden hose, but do not make a swimming pool out of it. The water will settle the sand and will show you again where your source and sink are. Once wet, let the sand sit for 15 minutes. Note where the water flows to on your sink end. This will be where you install a well. You can mark this spot by poking a stick in the ground outside the lip of the liner. Don't poke the stick through your liner. Smooth the wet sand. If your slope is too great (watering rushes to the sink end) this is the time to fix it by adding or removing sand in different areas. Remember, this is a slight slope, one inch every three feet.
Step 5: Filling the Bog with Peat
On a tarp next to the bog or on a cement surface nearby, mix peat (which is really chopped up sphagnum moss) with sand in the ratio 3:1 (peat:sand). This is the material your bog plants will actually grow in. The peat is extremely light and is easily air born. You may want to wear a dust mask when pulling it out of the bag and breaking up the clumps. Dampen the mix slightly with water to make it less flighty. The peat will hold a lot of water, so do not soak it at this point. Load your peat:sand mix into the bog using shovels. You should fill it to the top, even with the edge of your bog. Smooth the surface of the bog with the bottom of a rake. Water in your peat:sand using a garden hose. Don't blast your bog with a water cannon, just let water run into the source end. The bog will settle, and you may need to add more peat:sand mix to bring the surface even with the edge of your hole. You should also see the water flow from the source region to the sink. It is OK if water pools at the sink end, but you want it to eventually flow out the sink end and onto the ground. You may need to add a shovel full of peat:sand to the sink end so it matches with the edge of your hole. Once you have the bog well watered (with water running out of your source side), turn the hose off, go away, and let the bog settle for 24 hours.
Step 6: Dancing on the Bog and Packing it Down
The peat and sand need to be firm in your bog. Pitcher plants and other bog species like to be secure in their bog and need to be able to get a tight hold. Get some people together who do not mind getting their shoes wet (rubber boots come in handy here). Have everyone march all over on the bog, packing it in. Water should be coming to the surface where you step. After the entire bog has been packed down, get out of the bog, lean over and smooth the surface with your hands so that it is even again.
Step 7: Securing the Liner
Line the bog all around the upper lip with sand. No liner should be exposed to the sun. Sunlight breaks down the rubber rapidly. Lay stones or logs around the top of the bog on this sandy edge. This will hold the liner down and will define a boundary for the bog so people won't walk in it. Rocks and logs also give people a place to kneel or sit near the bog. You can cut any long pieces sticking out beyond the rocks with scissors.
Step 8: Watering the Bog
Cut a six foot length of soaker hose. One end will need a "stop block" (prevents water from flowing out the end), and the other end will need a "hose connection". We recommend a "quick connect" hose connection that allows you to click a regular hose into your soaker hose quickly without having to twist it on every time you want to water. Lay the soaker hose around the source end of your bog (upper end) in an arch on top of the sand covering the top lip of the liner (just within the rocks or logs anchoring the liner). The hose should be laying around the edge where the peat and sand begins in the hole. Bury the soaker hose 2" down into the sand covering it again with sand completely so it is not exposed to the sun. Leave the plug end (the end that connects to your garden hose) sticking out so you can get to it easily. When the garden hose is turned on, water will trickle out of the soaker hose and will wick through your bog following the slope to the sink end where excess water will run out.
Step 9: Building the Well
At the sink end of your bog, you may want to build a well for your runoff water to flow in to. In the spring and summer when you are watering about every other day, or when it rains, excess water will flow over the pond liner lip of the sink end of your bog. Some people choose to let this water flow. Depending on what other landscaping you are doing, you may need to catch this water. Since you have watered your bog by now, you know where the water is flowing and where the runoff water is heading (your stick should mark the spot). Beyond the edge of your plastic liner, dig a hole at least two feet deep and 1 1/2 feet in diameter. You can make it deeper than this but it does not need to be wider. This is your well. Fill the well to the top with gravel or small pebbles. Do not place logs or large rocks on the pond liner in front of your well. This will block the flow of excess water into the well and will cause the excess water to pool in your bog. You may need to dig 2 or 3" of soil from below the liner to allow the water to flow more freely form the bog to your well. Cover the pond liner in this area with sand only. The weight of the sand and the neighboring logs or rocks should be sufficient to secure the liner here.
Step 10: Building the Trench
You will need to build a moat or trench around the top half of your bog to protect it from any rain runoff. Fertilizers, pesticides, clay, sediment, and parking lot rain runoff are very bad for the health of your bog. They can carry anything from poisons to aggressive weedy seeds into your bog. Dig a trench one foot deep and one foot wide and about nine feet long around the top and upper sides of your bog. The trench should be outside, just beyond the edge of the pond liner. You want to look at the surrounding topography and any place where water from the surrounding area can wash into your bog, you want the trench to catch that water flow. Fill the trench entirely with sand. Make sure the pond liner lip does not lay into your trench. The trench should catch rain runoff and filter it below the bog, below the liner. The pond liner must be separate from this so the rain runoff does not leak from the trench and into your bog. Lift the edge of the pond liner up a bit filling under the edge with sand to ensure the water collected by the trench will not get into the bog.
Step 11: Dress Rehearsal
1. water should flow evenly and smoothly from the top through the bog and out the bottom,
2. the peat and sand should be even with the top of your bog and be mushy to the touch,
3. the top of the bog is packed down. Ok, you are ready to plant your bog! You may want to wait 24 hours after a rain or a one hour soak so it will not be so wet when you are planting.
Step 12: Planting Pitcher Plants in the Bog
Bog species can be planted the same way as the pitcher plants. Remove the plant from the tray or pot and gently loosen the roots so they extend their full length. The length of the extended roots equals the depth of the hole to plant them in. Dig a hole the length of the roots and suspend the plant within this hole with your hand. Make certain that the roots are able to spread out their whole length. This will help them to establish quickly in their new home. The crown of the roots (where the roots connect to the plant stem and leaves) should be even with the top of the hole. You do not want to bury the crown below the soil where it can rot or have it sticking up above the surface where it will dry out. Press the soil all around the roots with your fingers, planting it firmly. Once you are through planting the bog, immediately turn on the soaker hose and water the bog well for 30 minutes. Until your plants are established, you will need to water the bog daily for 15 to 30 minutes in the morning. You do not need to water the bog on days that it rains. The Sarracenia may not elongate or grow tall right away. First they will establish their roots. Then, they will grow more pitchers. Do not fertilize your bog, ever! Be patient, they will grow and bloom for you soon. Then you can collect seed for more studies and conservation work!