The word bog conjures images of muck, mire, and finned creatures. Perhaps that's why bogs fascinated me as a child. I experienced my first one when I was 14. I was immediately seduced by the array of orchids and heaths that carpeted the mossy mat beneath my feet. Most exciting of all were the carnivorous plants that grew everywhere in that floating habitat. But bogs are a far cry from the fertile purview of sci-fi, and it's not likely that you will get lost or devoured in the bogs I grow today. Though they contain many carnivorous plants, all are small, and planted in various containers, including a sink, a derelict wheelbarrow, and two galvanized cattle stock tanks.
A bog is a specialized peatland with highly acidic, nutrient-poor soil, which discourages growth of all but specialized plants—namely, carnivorous plants (pitcher plants, flytraps, and sundews) and orchids. This unique environment is easy to re-create in a container. The closed system allows you to carefully regulate soil, moisture, and exposure.
First off, you must provide a sterile substrate. Clean, sharp sand and peat moss are the best choices, in a ratio of one to two. I recommend installing a one- to two-inch PVC perforated pipe in at least one corner of the container, as you may be adding distilled water or rainwater to supplement rainfall.
Fill one-third of the container with pea gravel to provide a reservoir. Next, fill to the top with a mixture of 30 percent sand to 70 percent peat, and fully saturate the soil. It is imperative that the bog sits for at least a week before planting; a month is better but seldom practical. The pH of the soil and water need to come into balance before the plants will grow. The additional time also allows for settling.
Before planting, wash all the soil from the roots of the new plants to avoid introducing soil-borne microorganisms and worms. Position the crown just below the surface with the roots spread evenly through the medium. Add it after the other plants are in place. Your plants need full sun for best growth, but will squeak by with six to eight hours.
Resist the temptation to feed your plants. They catch plentiful prey on their own. Pitcher plants use the pit-trap method, luring insects to their beautiful leaves by sweet secretions. Insects slip on the edge of the trap, fall in, drown and are digested. Other carnivores use active traps. The Venus's flytrap is the most dramatic, with a snare that snaps shut when an insect walks across the trap. Orchids, meanwhile, have evolved to survive with the help of mycorrhizal fungi, which live symbiotically in the roots and provide nutrients.
Pitchers may get clogged with dead insects and begin to rot at the point of the backup, well above the digestive enzymes that render the prey useful. To avoid crimping pitchers, which spoil the display, stuff wads of cotton in the tops to keep insects from entering.
The most important maintenance job for a container bog garden is watering. The soil must never dry out. The glitch is that most tap water is neutral to alkaline and full of mineral salts and chlorine that will damage your plants. Well water may also be too alkaline. I harvest rainwater from my roof, and supplement with distilled water when necessary.
As old pitchers brown, remove them to keep the plants neat. Leave evergreen pitchers attached through the winter, and never cut the phyllodia—flattened photosynthetic leaves that don't form pitchers—until they start to decline once the new pitchers are fully expanded. Most bog plants are hardy to USDA Zone 5, but above ground containers are subject to freezing. In winter, I wrap mine in bubble wrap, then cover them with insulating blankets.
Bog gardens are not for everyone. They require special care. But with a little effort, you can have containers bursting with beauty and a touch of theater.
