Expert: Christopher Littrell - 8/25/2010

Question
Hi Christopher,
I bought a drosera madagascariensis about two weeks ago. At
the beginning the leaves were all sticky but now the glue
has disappeared. It's producing new leaves though and apart
from this glue problem the plant looks quite healthy. Still,
the new leaves have no glue.
I'm keeping it near a window facing east, so it gets some
direct sunlight in the mornings for a couple of hours.
Temperature shouldn't be a problem since it's summer here.
One thing i noticed is that the leaves are quite far apart
from each other (0.5-1cm) compared to the pictures i found
online. Maybe it didn't get much light in the past and now
it's not used to it? What can i do to make it produce glue
again?

Thanks a lot,

Sara

Answer
Hello Sara,

Drosera madagascariensis likes very bright, though not full, sunlight. Direct, full sunlight would be equivalent to the plant being outside with no cover from larger plants. In a window in your home, sunlight really is not direct as some of the UV radiation and intensity is refracted from the glass. Since the plant only gets very few hours of sun in the morning from a window, you might need to move the plant to a South facing window where it can get at least 6 to 8 hours of sun or add florescent artificial lighting over the plant. The problem is not too much light, rather, too little. Sundews need a large amount of light to produce dew. Dew is generated by the plant, not the humidity level, so sunlight powers dew production. The less dew and coloration the plant has, the less sun it is getting. When the tentacles are producing drops of dew and have red coloration, they are getting optimal light levels.

As a comparison, I have some Drosera adelae that need partial or indirect sun. They burn in direct sunlight, so they are perfect for placing in a bright window or under florescent lights. I have placed mine in South facing windows and under 16 hours of florescent light of 12000 lumens and stronger up to 8 inches from their leaves. They grow just fine, producing huge amounts of dew and color, and suffer no leaf burn even though they require much less light than your D. madagascariensis.

You can get a florescent light bulb spiral, 100 or more watts is best, for desk lamps and use those to increase the duration and intensity of light the window provides. Just keep the lamp on for at least 12 to 16 hours a day and keep it a foot away from the plant to ensure the leaves do not burn as those compact florescent lights are hotter than the florescent tubes. If you have a shop light of the 40 watt variety, they are cooler burning (so can be placed closer) than the compact and can cover a larger area (4 feet by 5 inches wide) if you have a number of plants to place under it.

Hope this helps,

Christopher