Expert: Christopher Littrell - 2/16/2010

Question
i live in southern Louisiana i have a drosera capensis it is February which means it going into spring should i put it outside or leave it inside it is in a terrarium with no top it if it is out side it will receive 6 or more ours of sun light if it is inside i have it in a terrarium still but it has artificial uva light it is a 70 watt bulb it is also not producing dew I've had it since February 5th i really want it to survive it is still green and growing so I'm wondering why it isn't making dew. I'm sorry i cant send a picture but it is green and healthy looking but it is also in regular soil without fertilizer could it be because of the soil. also it is a baby so it is pretty small but big enough to produce dew a while ago it did produce dew but it stopped

Answer
Hello Xavier,

There are several environmental problems contributing to the Sundew's inability to grow properly and produce dew.

Plants do not survive on ultraviolet light. The uva light is doing little to no good for your Sundew. Use cool white florescent tubes of the 40 watt shop tube variety or the 100 watt equivalent florescent compact bulbs. The best light for the cost would be the 40 watt shop lights. They have greater coverage area, emit cooler light, and can easily be mounted on a shelf or hung from a stand over your plants. You can also place the sundew outside, but keep it from being exposed to temperatures below 50-60 degrees for long as Drosera capensis is a sub-tropical sundew that is best left to grow year round in warm temperatures. It can go dormant, or semi-dormant, but would need environmental cues to enter a safe dormant period. If you place it outside, place it in progressively brighter places each week or two so that it can slowly adapt to full sunlight without being burned. If you use florescent lights, place the lights 6-8 inches from the leaves and use at least 12000 lumens of tubes, that would be four shop light tubes, or two or three compact bulbs about 8 inches from the plant. Keep the lights on for about 14-16 hours a day. Virtually all Sundews need good light to produce dew.

All carnivorous plants, including your Drosera capensis, usually have special soil considerations that have to be met or the plants will weaken and die. In the case of your D. capensis, it will need sphagnum peat moss and perlite in a 50/50 mix and no fertilizer in the soil at all. If the plant is in regular potting soil, it will die as even potting soil has fertilizers added by the manufacturer. Virtually all soils you find outside your house or for most regular plants have a mix of nitrogen and phosphorus that comes from natural bacterial action in the soil. Carnivorous plants live where bacteria have a hard time breaking down dead matter in peat bogs produced by areas of sphagnum moss. The moss produces iodine which slows bacterial action, making such potting material rather poor in nitrogen and phosphorus, something carnivorous plants adapted to live in by having roots that cannot stand fertilizers, yet leaves that catch and kill insects to absorb nitrogen and phosphorus from the dead bodies. Repot your plant in sphagnum peat and perlite immediately after washing the roots off with distilled or reverse osmosis water.

That brings me to another consideration. Your Drosera capensis needs mineral free water in quantity. Make sure to obtain rain water or distilled or reverse osmosis water with no minerals added as minerals, like free floating particles of calcium and magnesium, harm most carnivorous plants and are found in regular tap water and store bought drinking water for human consumption. Your Sundew will appreciate up to 1/4 of its pot standing in a tray of water and its soil moist at all times.

Sundews produce dew at all ages. The tiniest seedling Sundew will send up little leaves full of tentacles and dew. Drosera capensis grows to about 6-8 inches across and can produce a one foot tall flower scape.

In addition, your sundew would do much better outside the terrarium. Place it in a regular pot with a large tray of water under it. Place a clear bag or plastic dome over the plant and punch about a half dozen 1/4 inch holes in it every three days until about 2-3 weeks have passed, then take the dome or bag off the pot. The plant should be adapted to your household humidity at that time. Most carnivorous plants do not require high humidity and can be grown in low humidity if they are adapted slowly to such. Terrariums tend to induce mold, high temperatures, and inability to provide as much light as many plants require.

Christopher