In the Garden: Pass the Spiders, Please


By Charles Kidder

Vegetarians may object to eating meat, but the 630-odd species of carnivorous plants have no such scruples. To be fair, carnivorous plants have merely adapted to a harsh environment by eating meat, whereas humans can obtain their nutrition in a variety of ways. But lifestyles aside, carnivorous plants can provide an interesting twist to your garden.

Botanists think that the somewhat odd habit of plants eating meat may have evolved independently six times, generally as a response to very poor soils. Carnivorous plants are typically found in bogs or wet savannas with abundant water and sunlight, allowing them to thrive if they can solve the missing nutrient problem. Bugs are able to supply what the substrate lacks, so the plants just had to figure out how to catch them.  Meanwhile, occasional fires—bogs can periodically get quite dry—keep down competition from other plants.

To catch their prey, the plants employ one of five techniques, or perhaps some combination of these. Pitfalls employ a modified leaf that encourages the insect to fall into a vase-like structure. Flypaper, as the name suggests, is just a sticky leaf.  Snap traps are the movable leaves found on Venus Flytraps. Bladder traps are underwater structures that can suck in their victims, and lobster traps are easy-to-enter, hard-to-get-out mazes.

Sundews (Drosera spp.) are a genus of almost two hundred species ranging over much of the earth; a handful of these are found in the southeast United States.  For us they are small to tiny plants that are hard to spot, even though they may be quite abundant.  You may be fortunate enough to encounter them at the edges of bogs, ponds or ditches in the Coastal Plain.  At first, you won’t notice anything unusual, but then you’ll become aware of tiny red dewy dots hiding among the general greenery. You might then realize that you may have already stepped on a few hundred sundews. They will likely recover and continue to use their sticky leaves to trap tiny insects.

If the sundews are the retiring violets of the carnivorous plant world, the pitcher plants are almost in your face. The Sarracenias, generally native only to the southeast U.S with one species ranging up into Canada, send their trumpet leaves up to thirty inches above the ground. The pitcher-shaped leaves employ a variety of strategies to tempt insects in; they then fall to the bottom and are digested. Leaf color ranges from yellow-green on some species to burgundy on others. Since pitcher plants readily hybridize, there are many cultivars with differing coloring and leaf size. Just one example: Sarracenia leucophylla ‘Tarnok’ has red-veined, cream-colored pitchers topped by red and chartreuse double flowers. The foliage on pitcher plants is so showy that most people don’t even think about the flowers, rather bizarre things specially shaped to prevent self-pollination. The flowers are held well above the leaves; after all, it’s not nice to trap your pollinators and eat them.

Unlike the pitcher plants that employ no moving parts in their trapping, the Venus Flytrap (Dionaea muscipula) employs its infamous “mouth” to grab its prey. Despite the fearsome appearance in close-up photographs— not to mention fictitious representations—flytraps can be hard to spot in the wild. Only 2”-3” tall, they can easily hide among taller vegetation; for years I walked by a patch before finally noticing it. And although the innards of the trap may be a showy red, they can just as often be a harder-to-spot yellow-green. Speaking of those traps: if you have a “pet” flytrap or encounter them in the wild, don’t make them do tricks by tickling their leaves to watch them close. This just wastes the plant’s energy. But if you happen to find a hapless spider nearby…

Venus Flytraps are the only species in their genus and have a very limited distribution. Depending on the source that you check, they grow as natives only within 50-75 miles of Wilmington, North Carolina. Habitat destruction, fire suppression and poaching are all conspiring to limit their numbers. Never buy them from roadside vendors. Online dealers should clearly state that their plants are not wild collected.

What about growing carnivorous plants in your garden? Given their strange nature, it’s easier than you might expect. There are just a few basics to remember: light, water and soil/nutrients. Starting with your planting medium, ordinary potting soil or garden soil will overload your CPs with nutrients, which they don’t want.  A good soil mix is one part sphagnum to one part sand. The sand must be horticultural sand or play box sand, not contractor’s sand or beach sand.  Wet the soil mix thoroughly before planting. Plastic pots are best, as long as they have one hole in the bottom.

Once planted, full sunlight to part shade is required. As for water, it’s virtually impossible to overwater CPs, but be careful what type of water you give them.  Ordinary tap water or bottled water will lead to nutrient overload. Rainwater or water from your downspouts is good, as is distilled water. Keep the pot in a tray that always has at least ¼” of water in it.

As for supplemental feeding, do not toss your CPs hamburger or other bits of meat!  They want live prey, and if they’re outside they should be able to find it. Outside is probably the best place for them, although they can be kept indoors if you can find them an occasional insect, maybe one every ten days to two weeks. But as temperate plants, they require a dormant period, so they should go outside or to a very cool basement for the winter.

All this talk about eating has me wondering what the omnivore should have for lunch.  Maybe the Pan-Seared Farm-Raised North Carolina Venus Flytrap with Spider Stuffing? 

Excellent choice.



Please enter your comment!
Please enter your name here