Tropical Sundews

Tropical Sundews: Drosera sp.

by Michael and Andreia Stiffler


General information

The Drosera are given the common name of sundews, as their glandular leaves glisten in the sun. There are approximately 135 sundews species in the world, most of them growing in tropical environments. The species most encountered in cultivation include the cape sundew Drosera capensis (perhaps the easiest carnivorous plant to grow), small rosetted sundews like D. spatulata and D. aliciae, and the Queensland sundews D. adelae and D. prolifera. The surfaces of sundew leaves are covered in stalked glands, or tentacles. At the end of each tentacle is a small, typically reddish gland that produces a tiny drop of dew—a clear and sticky mucilaginous substance. Perhaps attracted by the red color of the glandular tips, or by mistaking the glistening droplets for nectar, an insect lands on a leaf and quickly becomes mired in the sticky dew. Digestion then begins as the stalked glands also produce digestive juices containing digestive enzymes and bacteria.

Species: D. capensis, small rosetted sundews (e.g. D. spatulata, D. aliciae), D. multifida, D. prolifera, D. adelae, pygmy sundews (e.g. D. scorpiodes), tuberous sundews, D. regia, and many others.


Cultivation

Soil: A mix of one part peat to one part course sand is excellent for most.


Containers: Plastic pots are recommended, however glazed ceramics will also work.


Watering: Use only chlorine free water with low mineral content such as distilled, reverse osmosis or rain water. Some public water supplies in New England are adequate—check with your water company or other NECPS members. Use the tray method keeping the soil damp to very wet.


Light: Full to mostly sunny. Most tropical Drosera thrive outdoors in the summer in full sunlight. Indoors, they can be grown in terrariums under fluorescent lighting. Typically, plants should be kept as close to lights as possible (less than 6 inches is ideal).


Growing conditions: Most are good for well-lighted terrariums, although some species may need large terrariums. In the summer, many will do well outdoors or in greenhouses. Some may do well on sunny windowsills.


Dormancy: Tropical sundews do not require an extended winter dormancy period. However, some species, like tuberous sundews and some South African species, do go dormant during the dry summer months.


Feeding: When outdoors they will feed themselves on small flies, ants, mosquitoes, etc. Indoor plants may feed on gnats and springtails if available in the environment. Hand feeding can be accomplished using store-bought crickets or freeze-dried fish food (mosquito larvae such as bloodworms).


Propagation: Propagation by seed is the easiest method. Flowers of many tropical Drosera species (like D. capensis and many small rosetted sundews) will self-pollinate upon closing and produce copious amounts of seed. Leaf cuttings and root cuttings also work well for many species. Pygmy sundews are unique, as they produce brood bodies called gemmae, which can be sowed like seed.


References and for more information

1. D’Amato, Peter. 1998. The Savage Garden. Berkeley, California.: Ten Speed Press.

2. The Carnivorous Plant FAQ