Pitcher plants are carnivorous bog plants found from the Gulf Coast to Hudson Bay. They are named for the tubular leaves that contain insect-digesting enzymes. Photo for The Washington Post by Bert GF Shankman

Washington - Somewhere along the evolutionary timeline of bog-dwelling angiosperms, the plants gathered together and decided they wouldn't take it any longer.

No more would insects see plants as the ultimate salad bar. The time had come to fight back. The time had come for the plants to start eating the bugs.

All right, it may not have been that cinematic. Our favourite plant carnivores turned to meat because their chosen evolutionary niche - soggy and acidic peatlands, for the most part - didn't provide enough soil nutrients. And although this may be a more prosaic reading of their botanical origins, the way veggie carnivores have engineered themselves to consume animals is genuinely wondrous and amazes each generation that grows up to discover this phenomenon.

Michael Szesze was 10 in the early 1960s when he came across the bizarre Venus' flytrap, which appealed to young minds because it seemed to be a plant well on its way to becoming an animal. Not only did it digest insects, it clasped them like a bear catching salmon. It was animated.

Today, for a number of converging reasons - the age of social media, the popularity of ecological gardening and the breeding of variants - the interest in carnivorous plants has never been more intense or widespread.

Szesze, 65, fills about 50 orders a week, and the success of his nursery, he says, is testament that "it's not just geeks buying the plants."

GROWING CARNIVOROUS PLANTS

If you don't have a greenhouse, and most people don't, there are three basic ways to grow most carnivorous plants, as long as you are in plant hardiness Zone 6 or warmer.

Indoors: Some carnivorous plants simply are not suited to indoor environments, though a few tropicals will work as windowsill plants if, in winter, they can be kept humid and away from direct heating or cold drafts. However, a terrarium with its own supplemental lighting is a better environment. Temperate plants should be allowed to go into dormancy during the winter by reducing water, temperature and light levels.

Outdoors in containers: This is the easiest way to grow hardy bog plants, but make sure the pot is big enough. A container that is too small will stress plants in winter (from freezing) and in summer (from evaporation). Szesze suggests a pot at least 10 inches across, and, of course, it has to be of material that is freeze-proof.

Szesze makes small gardens for patios with a medley of plants in low, broad plastic containers. He drills quarter-inch drainage holes on the side of the pots, just one inch or so below the lip. This allows the soil to remain saturated without flooding the plant crowns.

In a bog or raised bed: Building a bog garden is no small feat. You have to bring in large quantities of sand and peat moss and devise a way to keep it moist; the installation costs can add up.

Instead, you may want to consider a raised bed. Szesze has built an elevated display garden at his nursery, a five-sided timber-framed bed measuring roughly eight feet wide and 10 feet long. It is well stocked with various pitcher plants, bog orchids, violets, gentians, sundews and flytraps. It took 12 wheelbarrow loads of soil.

If you have an existing pond, you could fashion a bog at its margins, though it would have to be free of any fertilizer runoff from surrounding areas as well as the buildup of fallen leaves or other organic matter.

I have my pitcher plants growing in pots on a planter ledge in my fish pond, about four inches below the water line. As long as the water doesn't get too high - and certainly not above the soil line - the plants are happy.

CARE AND FEEDING

How do you kill a carnivorous plant? By treating it like just another garden perennial or houseplant.

  • Plants will die in conventional garden or potting soil, which is too rich. Use a mix of one part sphagnum peat moss to one part sand. Living sphagnum moss - the generative material of a peat bog - can work as a mulch, much as it would in a natural bog.
  • You can't use municipal water, which has too many minerals. The choices are collected rainwater, distilled (not bottled) water or well water.
  • Feeding with fertilizers, including organic fertilizers, will also imperil the plants. Plants do need an insect meal, but only occasionally, and when outdoors in the garden they probably can feed themselves. Growers of indoor plants can use freeze-dried insects from a pet shop or wingless fruit flies.
  • Don't use raw meat or cheese, says Szesze, which will rot, kill leaves and compromise the whole plant. Flytraps need to feel a struggling insect to fuse their leaves for the meal, he says.
  • Closing a trap takes an enormous amount of energy, and if all that work is not rewarded with an insect, the plant is weakened. "The worst enemy of the Venus' flytrap," he says, "is a kid finger-poker."