Oudean

Sundews lure and trap insects using a fragrant sticky substance. Hair-like tentacles on the leaves support glands that produce this natural glue. The droplets of glue make the plants’ leaves glisten in the sunlight like a spider web touched by morning dew. The dewy substance allows the leaves to trap small insects like flypaper traps flies. Some sundews’ leaves appear to actually fold over the trapped insects. Others are not as obviously active. All digest and absorb the contents of the insects’ bodies through their leaves. The Forked sundews, D. binata, D. multifida, D. dichotoma (their forms and hybrids) and the Cape sundew, D. capensis (all forms), are particularly effective as bug patrol in greenhouses, on windowsills and on the summer patio. They are among the largest of the sundews and some of the easiest to grow. They hungrily trap the white cabbage moth, mosquitoes, fungus gnats, crane flies, fruit flies and other tiny insects.

It is not necessary to feed sundews. Photosynthesis provides for the plants basic needs. But, if you are looking for an interesting science project you can easily collect and raise you own gnat supply. Just cut a large hole halfway up each of two opposite sides of a plastic milk jug. The “Gnat House” can be decorated with permanent marking pens, crayons or acrylic paint. Place a cup or so of wet Fruit Loops and a banana peel in the bottom of the jug. Hang it somewhere out of the way, indoors or outdoors. Gnats will be attracted to and breed in this environment. To feed the sundews, hold the jug in front of the plants and gently blow through the nearest hole in the container. This will send some gnats onto the plants through the opposite hole. Escapees will be attracted back to the plants and trapped. Meat is not a good substitute for insects. Harmful bacteria grow in the meat faster than the plant’s digestive enzymes can break it down.

Many warm climate sundews have long blooming seasons. Their flowers are shades of lavender, pink, white or red, depending on the species. Most hardy and warm-hardy sundews are spring blooming in shades of lavender, pink or white.

A. Warm Climate Sundews: Best temperatures for summer, 50°F to 90°F, winter, 45°F to 70°F

Species discussed: Drosera aliciae, D. binata (all forms), D. adelae, D. capensis (all forms), D. capillaris (tropical forms), D. coccicaulis, D. dichotoma (all forms), D. dielsiana, D. hamiltonii, D. multifida, D. multifida ‘Extrema’, D. x ‘Marston Dragon’, D. natalensis, D. regia, D. slackii, D. spathulata (tropical forms), D. venusta, D. intermedia (tropical forms), D. prolifera and their hybrids.

a) Indoor Culture: D. prolifera needs to be grown in a covered terrarium or seal the potted plant in a Ziplock bag. D. adelae, D. regia and D. prolifera like east or west facing windows, just back from direct sunlight where they will not be cooked by hot sun. Late morning and early afternoon sun is best for most other sundews. They need at least 4 hours of sunlight a day. 10 to 18 hours of light provided by two 32W fluorescent grow lights in a shop light fixture or a 23W 5000K compact fluorescent plant light in a desk lamp, located 4” – 6” above the plants’ leaves, will do the trick if there is no convenient window. In cloudy coastal areas, artificial light is a must in winter months. Pinch off flower stalks to conserve the plants’ energy except in summer months. If the dew dries up, the sundews need higher humidity. If the leaf tips turn brown they are too hot or too cold.

b) Summer Patio Culture: In cloudy coastal areas, place the plants in full sun. In hot climates, give them shade during the hottest part of the day. D. Adelae, D. regia and D. prolifera want partial shade all day in most climates.

a) Indoor Culture: These are bog plants. Never let the soil dry out. Keep the potted plants in bowls of water 1” – 2” deep during the growing season. D. binata, D. dichotoma and D. multifida forms and varieties (the Forked sundews) and D. capensis forms (the Cape sundews) will tolerate drier conditions in hanging baskets with deep trays. The top inch of soil may be allowed to dry a little if the roots stay moist. Use rain or distilled water and fill the baskets until the tray is full and overflowing each time you water. When you are on vacation, place the baskets and other pots of sundews in bowls of water and raise the water level almost to the top of the pots. The water level can drop to about 1” while you are gone.

b) Summer Patio Culture: This is a bog plant. Do not allow the soil to dry out. It is less of a chore if the plants are in large pots, set in deep water bowls. While the plants are still in their semi-dormant stage, pot them in large pots with holes in the bottom. Place the potted plants in a bowl that is at least 2” shorter than the pot. This will keep the sundews from being submerged in water by a rainstorm. Check the water level often in hot weather. It can fluctuate from 2” below the top rim of the pot to ½” above the bottom of the pot. Place them outside after all danger of frost has passed. Warm climate sundew can be grown outdoors all year if you have a frost-free climate. Some will tolerate brief light frosts. All do well grown as houseplants for the winter. If the plants get leggy or lose red color tones, give them more light. Do not fertilize.

B. Warm-temperate Sundew: Best temperatures for summer, 40°F to 90°F, winter temps, 20°F to 70°F

Species discussed: D. capillaris, D. filiformis ssp. filiformis var. ‘Florida Giant’, D. filiformis ssp. Tracyi, D. filiformis x ‘California Sunset’, and D. spathulata.

Species that can be grown as warm temperate: D. binata (all forms), D. dichotoma (all forms) and D. multifida (all forms).

C. Cold-temperate (Hardy) Sundew: Best temps for summer, 40°F to 90°F, winter temps, 0°F to 40°F

Species discussed: D. anglica, D. arcturi, D. filiformis ssp. Filiformis (northern forms), D. intermedia, D. linearis, D. rotundifolia and natural hybrids, D. x hybrida, and D. x obovata.

1. Indoor Culture: The general care of cold-temperate and warm-temperate sundews is the same as for the warm climate sundews. The main difference is their dormancy.

a) Warm-temperate sundews may die all the way back in the fall. They have a short dormancy requirement. They will come back from the roots and the crown in just a few months. If you don’t have good light conditions in the winter you can extend the dormancy to as many as 4 cool (20°F to 45°F) months. In low light they can come out of dormancy too soon, grow long leggy stems and even exhaust themselves. Provide fluorescent light or extend their nap until natural light levels increase. Keep them damp all winter. Move them to a frost-free garage or basement window if the house is kept above 50°F. If you are using fluorescent lights they can have a warm dormancy.

b) Cold-temperate sundews need a dormancy of 4 to 6 months of temperatures at or below 40°F. They will go into the tight leaf bud of dormancy for the winter, even in warmer temperatures. If your climate is extreme or outdoor culture is not possible, grow your plants in a cool southeast or southwest window, in the summer. When they go into their dormant bud in the fall, pack them in damp (not soggy) sphagnum moss or damp paper towels and place them in a labeled and dated zip-lock baggie in the vegetable draw of the refrigerator for the winter or just move their pots and water tray to the basement or garage. They may rot if they are kept at warmer temperatures. Repot them and place them in the window in February or March.

2. Outdoor culture: If you use the right temperate sundews for your microclimate, outdoor bogs are the lowest maintenance method yet. Build your bog in a sunny area. Do not let the bog go completely dry in summer. Mulch the bog with evergreen boughs or fern fronds 4” to 6” deep in the winter if temps drop below 20ºF. See our bog sheet for simple, quick and easy bog building instructions.

D. Potting Instructions: For plants grown indoors, yearly re-potting prevents mineral-salt levels from reaching deadly concentrations. Warm climate sundew should be repotted during active growth. Temperate sundews like to be repotted while they are still dormant or just breaking dormancy. A pot depth of 6” to 8”is all that is necessary for D. binata forms, D. dichotoma forms, D. filiformis variations, and subspecies, D. capensis forms and any of their hybrids. Deeper pots are fine. Other smaller sundews will grow happily in 2” to 4” deep pots. When repotting D. prolifera, place some sphagnum moss in the top 1/4 of the pot on top of the soil mix. Gently nestle the plants in the moss.

You may have seen the words “Live Plants” printed on a box. Unlike most other plants, the Venus’ Flytrap demonstrates just how alive it is in a very surprising way. It quickly and actively traps, then digests its dinner. Insects are lured to their death by nectar glands in the guard hair margin of the trap. To insects, the nectar smells like raw meat. Insects that pollinate are not attracted to it. Each trap leaf may catch and digest 3 - 4 times before dying and turning black. It takes about a week for the traps to digest an insect and reopen between meals. Traps, that are triggered but not fed, will open in 1 day and can be triggered up to 11 times before they die. Cut off, don't pull, any black tissue. The plant will not die if one trap dies. It produces new leaves frequently during the growing season. Dining on insects is not necessary to the plant's survival; but 2 or more meals per plant, per month, will improve its general health and trap size. Luckily, it cannot overeat when food is abundant. If you want to hand feed your plant, any small bug is a good meal. Tiny crickets from the pet store are fine. You can feed the traps with bugs you have just killed; but a struggling victim aids the plant’s digestion. If the meal is too large for the trap to close and seal properly around the food, the trap will gradually die. Feed very small meals until you can judge size accurately. Meat is not a good substitute for insects. Bad bacteria grow in the meat faster than the plant can digest it. Fertilizers can be harmful. The rest of the plant's care is quite simple. Adequate light and water are vital to the plant’s survival. They can live many years if you provide what they need.

1. Light Requirement:

A. Indoor Culture: Place the plants in a south facing window that gets direct light for 6 - 8 hours, measured in June, or in 10 or more hours of light a day, provided by two 32W fluorescent tubes in a shop light for dozens of plants or one 23W 5000K compact fluorescent plant light in a desk lamp for every 3 or 4 plants. Place the lights 4"- 6" above the plants’ leaves. When Halogen or Halite lights are placed close enough to the plants’ leaves to produce the right light levels, the lights give off too much heat and cook the plants’ leaves. VFT can also be grown in a terrarium with two fluorescent plant light tubes. Keep the tank out of direct light or you will fry your plants. Pinch off the flower stalk to divert the plant's energy to making traps.

B. Outdoor Culture: In the Pacific NW, place the plants in at least 4 hours (more is better) of direct, unfiltered, late morning and early afternoon sunlight. In hot climates, shade the plants from the sun during the hottest part of the day. Flower stalks may be allowed to flower and seed out.

2. Water Requirement:

A. Indoor Culture: This is a bog plant. Never let the soil dry out. Keep the pot in a bowl of water 1"-2" deep at all times. Use distilled or rain water. Going on vacation? Fill the bowl with water to the top of the pot before leaving. The plant is occasionally flooded in its natural habitat.

B. Outdoor Culture: This is a bog plant; it requires constant moisture all year. Creating a miniature bog is easy and inexpensive. A Rubbermaid dishpan or a child’s wading pool is great for this purpose; but you can use any watertight container 8” deep or deeper and 18” wide or wider. It can be made of anything except treated wood or unsealed cement. Most carnivorous plants do not tolerate calcium, alkaline conditions, or petroleum residues. Find a location in full sun with no overhanging plants or eaves to obstruct rainfall. Excess water should drain away from your container in heavy rain. Dig out a level area large enough for your container to fit with its top edge at the same level as the surrounding dirt. Remove any sharp objects from the hole. Place 1” - 2” of sand in the bottom and line it with newspaper, 4 or more sheets thick. Drill a 3/8” – ½” hole, 2” below the top edge of the container. Place the container in the hole. Arrange rocks or bricks as a retaining wall so that 1/4 of the container will be a small pond. Line the empty soil area with weed cloth. Fill it with soil mix, made of 1 part clean sand (see potting instructions) and 1 part peat moss, thoroughly mixed and wet. Press the soil mix firmly, mounding it slightly. Plant the Venus’ Fly Traps in the center of the mound. Slowly, fill the pond with water. Gently, water the plants to clean and settle them. The water level in the pond may be allowed to drop to 1” in the summer, between refills as long as the soil surface remains moist. Do not allow the soil to dry out. The larger the container, the less care required, as long as 1/4 or more of the surface area is a water reservoir (pond). In hot climates. 18” to 24” containers are best.

The Venus' Fly Trap is not a tropical plant. It is a hardy bulb-like rhizome, native only to certain boggy regions of the Carolinas, right here in the USA. It appreciates a period of rest in the winter.

A. Indoor Culture: place the plant in its water tray in an unheated room or garage where temperatures do not drop below freezing, 35°F - 45°F, for 3-5 months, e.g. December-March. Date a strip of tape on the pot for reference. If you don't have a cool place indoors, artificial light must be provided, see paragraph 1.A.

B. Outdoor Culture: if you live where winters are dry, water your bog as needed to keep the soil moist. In climates where temperatures drop below 20°F for long periods of time, insulate the plants with 6” of fir or pine branches, when freezing temperatures are about to begin. If temperatures drop below 10°F for more than a day or two at a time, add a cover of rigid Styrofoam or frost blankets. Remove the insulation as soon as all danger of frost has past.

A. Re-pot yearly during active growth in a wider pot or the same pot with fresh potting mix. A pot depth of 3" is all that is necessary, but deeper pots are okay. Just raise the water level to 2" - 3" below the top of the pot. Use a potting mix of 1 part clean builders sand or superfine perlite to 1 part peat moss. You can use sand from creeks or riverbeds where ground water tests acid pH with an aquarium water test kit. The pH should read 4 to 6.5. Do not use sand from sources contaminated by salt water. Do not fertilize.

1 part clean builder’s sand or superfine perlite to 1 to 2 parts peat moss. You can use sand from a river or creek bed. Test the groundwater and the moving water with an aquarium test kit. If either reading is neutral to alkaline get your sand somewhere else. Do not use sand from sources contaminated by salt water. Do not fertilize.

The Care and Feeding of Drosera, Sundew Ó 2004

By Karen Oudean