Sundews (Drosera) are a diverse collection of carnivorous plants, growing in many parts of the world under a variety of conditions. Sundews grow in nutrient-poor soil and need to obtain food from an external source, usually mosquitoes, midges and fruit flies. The leaves of the sundew plant are covered with sticky growths that trap unsuspecting insects. This natural adhesive contains enzymes that break down the insect's body, allowing the plant to digest needed nutrients from its prey.
Sundews grow on every continent except Antarctica, but the subtropical species are the most popular choice for terrarium and greenhouse enjoyment. Similar looking species from Australia, South America, southern Asia and Africa include Drosera dielsiana, natalensis, ascendens, venusta and trinervia. All feature reddish tentacles, tipped with a glistening drop of a sticky enzyme secretion that resembles a drop of harmless dew which give the plant its name.
In the wild, sundews grow in nutrient-poor soil, but in captivity they are not picky about a growing medium. A typical carnivorous plant soil mix contains sand and peat moss. The mixture can contain as little as 30 percent peat moss or as much as 100 percent--these are adaptable plants. Sundews can be grown in sphagnum moss as well. To maintain adequate moisture, grow sundews in a ventilated glass or plastic terrarium.
Light, Temperature and Moisture
Sundews need at least one or two hours of direct sunlight. Grow these plants in an east or west facing window or under a fluorescent bulb for best results. Normal household temperatures--about 70 degrees Fahrenheit in the day and 55 to 60 degrees Fahrenheit at night--nicely mimic the subtropical environment of sundews. Don Janssen, extension educator at the University of Nebraska Extension, recommends using rain or distilled water when watering sundews. Tap water, he feels, "may be too alkaline or contain too many minerals."
Growing From Seed
Sundews can be grown from seed. Prepare a container with equal parts peat moss and sand. Distribute the seeds on the surface of the soil and mist thoroughly. Do not cover the seeds with additional potting mix. Put the pot in a plastic bag to maintain humidity and place in a warm location, between 70 and 80 degrees Fahrenheit. Sundews can take up to a month to germinate, so be patient. Once the plants have true leaves, remove the bag and place the plants in a terrarium.
Do not fertilize the soil of sundew plants. Once plants have developed their characteristic "dewy" leaves, the International Carnivorous Plant Society recommends a diet of rehydrated blood worms (available in pet stores) or small insects (available in your yard). To feed a blood worm, dip it in water and place gently on the leaves. Use the same technique with small gnats, fruit flies or mosquitoes. If your offering becomes moldy, you have overfed. Remove the excess, and any remaining mold, with a cotton swab dipped in rubbing alcohol.