There once was a clever plant that swallowed a fly… and thought it was delicious! There are places in the world where the soil is so poor that plants have evolved ways of gaining nutrients with less conventional methods. They still photosynthesize (harness the sun’s rays) as their main source of energy, but in addition, they actively attract insects to consume as a nutritious dessert.
Plants have developed such mechanisms in many different environments, giving rise to nearly 600 carnivorous species that have all sorts of outlandish structures to ensnare prey. They’ve thought of everything from sticky foliage (Sundews) to pitfalls (Pitchers) and even snapping traps (Flytraps). Not only are these sinister adaptations fascinating—they can also serve a practical function for humans by secreting a musky odor to attract nuisance insects like gnats, mosquitos, and flies. During summer’s tomato season (a.k.a. gnat season), place a Sundew in your kitchen window to get rid of those pesty gnats and save your fresh glass of wine! Luckily, most varieties of commercially-available carnivorous plants are quite easy and rewarding to grow.
- Sundews (Drosera capensis, Drosera binata)
- Pitcher plants (Sarracenia flava)
- Butterworts (Pinguicula grandiflora,
- Pinguicula moranensis)
- Venus flytraps
- Asian pitchers
- Cobra lilies
Indoor Growing (bright, sunny window facing east, west, or south)
- Tropical sundews (Drosera capensis, Drosera spatulata)
- Asian pitchers (Nepenthes)
- Mexican butterworts (Pinguicula)
Outdoor Growing (4–6 hours of sun or more)
- Venus flytraps
- Pitcher plants
- Cold-hardy sundews (Drocera filiformis)
- Cobra lilies
Other Deciding Factors
Sarracenia/pitcher plants are expert yellow-jacket catchers! Sundews, especially tropical varieties, are great in bright kitchen windowsills and love to trap and eat the fruit flies around composts and fruit bowls!
There are many carnivorous plants for growing both indoors and outdoors, but they will not thrive in areas that receive less than 3–4 hours of direct sunlight daily. Flytraps and Sarracenia need more sunlight than they normally receive indoors and often die due to lack of sunlight. They are not recommended for indoor growing, unless given special attention (supplemental light and a chill period for dormancy).
Never use potting soil or garden dirt! The best soil blend for carnivorous plants consists of equal parts peat moss and pearlite; pearlite can be substituted with pumice or washed river sand. Carnivorous plants are sensitive to most plant fertilizers and minerals and prefer to get their vitamins from the bugs they eat!
Most carnivorous plants favor high humidity and soil that is constantly moist, but not wet (bog-like conditions); best grown in a container with a large tray under the pot with plenty of water. They also prefer water with no chlorine and low mineral content; for best results, use distilled/filtered water or rainwater. If growing in a pond or fountain, make sure the water level is no more than halfway up the pot to keep the crown of the plant above water. Some plants, like cobra lilies, prefer moving water over standing water.
Outdoor carnivorous plants usually catch plenty of insects and often do not need fertilizer. They are sensitive to over-fertilization—feed only if necessary. Indoor plants may enjoy occasional fertilizer; use a urea-free formula for orchids or bromeliads and dilute to half the recommended strength. Do not feed meat to your plants; provide a freshly caught insect or just let them catch bugs on their own.
Ironically, carnivorous plants can be prone to insect pests, especially aphids, scale, and mealybugs. Fungal diseases (mainly grey mold) can also occur with poor air circulation. Neem oil is the ideal fix for both issues—it works as an insecticide and a fungicide. Slugs can pose a concern for outdoor plants as well; use Slug Magic for best results.
Although most plants can be repotted any time of the year, it is best to repot in late winter or early spring for the best-looking summer plants; be sure to use proper soil mix when repotting.
Temperature & Seasons
Cold-Hardiness: As winter approaches, hardy plants will slow in growth and eventually stop growing. They may retain leaves, but the leaves will turn brown around the edges; this is perfectly normal. Most hardy carnivorous plants require 3–4 months of winter dormancy triggered by temperatures below 50°F and shorter daylight hours. Even while dormant, plants will still need to sit in a small amount of standing water to prevent the soil from drying out. Don’t worry about overnight temperature dips as low as 20°F. While dormant, these plants can tolerate overnight frosts with minimal winter protection. However, they are very susceptible to freeze damage when grown in containers. Protect plants if there are extended periods below 20°F or whenever there is a combination of freezing temperatures and wind, which can cause serious frost burn. To prevent frost burn, cover plants with black plastic or a tarp, or move them into an unheated garage or shed. As soon as the temperature climbs above 35°F, uncover your plants and allow them to continue dormancy outdoors. Once temperatures begin to warm in early spring and plants begin to regrow, cut off all of the old foliage to make way for new growth and preserve ideal plant health.
Heat Tolerance: Carnivorous plants are extremely heat-tolerant of a wide range of temperatures, but it is best to avoid prolonged soil temperatures above 100°F. To cool the roots in containers during extreme heat, water plants once or twice per day with cool water and/or move into area where roots receive less extreme temperatures.