Question
A few weeks ago I received a drosera intermedia cuba.  It was not in very good condition.  I put it inside my terrarium and it seemed to have recovered.  However, a few days ago, I noticed it had stopped producing dew.  I put it outside where a similar plant of the same species was doing fine.  However, the drosera intermedia cuba has not begun producing dew.  Should I move it back inside the terrarium?  Typically, our summer weather is hot and humid at this time-80 degrees.  These past days have been relatively low humidity with high around upper 70's

Answer
Hello Caleb,

First off, most carnivorous plants, Drosera intermedia (Cuba) included, can adapt to low humidity quite well and produce dew normally. Terrariums are only useful with plants that simply are unable to be grown open pot at all.

Since the sundew is in poor condition, you will need to keep it in a stable place where it does not experience rapid humidity and temperature flucturations. What happened is that the plant seemed to recover due to higher humidity, which will help in the short run, however; as you now see, the plant stopped producing dew due to low light levels inside that terrarium. Now that you have taken it out, the humidity dropped again, so the plant reacted by going into humidity shock.

Place a plastic sandwich bag over the pot and punch about half a dozen 1/4 inch holes in it, then place the plant under the brightest florescent light you can. The problems with covering a plant with a humidity dome is that the plant can become dependent on the humidity and that you will be unable to give it proper light until you get the dome off (you can't put it in sunlight as it can and will cook in that bag). A conundrum that you can solve by punching 2-3 more holes in the dome every three days until it looks like Swiss cheese. By the end of the second week of this treatment, you should be able to take the dome off and the plant should be better suited to low humidity levels.

Next, place the plant in higher light levels progressively. All that time spent under humidity domes and terrariums and stuck in dark boxes in the mail have taken their toll on the plant's ability to tolerate ultraviolet radiation, so you need to baby it a bit so it does not get burned. Try a morning sun window for a week, then a south facing window or outside on a sunny, but slightly shaded patio or under a large tree for another week. Each week, keep placing the plant in sunnier conditions after getting that bag off until it is in direct sun most of the day. That should take about 2-3 weeks. Make sure that the moves you make do not result in areas with drastically lower humidity or temperatures or it can drag the plant down again.

If you can nurture the plant through this low point, it will respond with bright red tentacles and leaves and produce large amounts of dew.