All Things Petiolaris

[bluemax]

It seems to me that there is a lot of interest in sundews of the petiolaris complex but not a lot of information out there. I consider these plants to be some of the most beautiful and interesting of all Drosera, if not all plants. They continue to be rare in cultivation and expensive to buy when they are available at all. Many consider them to be too difficult to grow but the irony is that once you have found a way to provide them with the continuously warm temperatures and high humidity they require they become quite easy to cultivate. It would be nice if more growers were able to enjoy these plants from close up. I hope this can be a place where information about petiolaris sundews can be exchanged, questions can be asked and growers can post their photos. There are many threads about this group of plants but nothing really encompassing yet. So - what do you have?

I can start with this. These are photos of my set-up in a 10 gallon aquarium tank. If the plants look kind of ragged it's because most have been divided lately or still need to be.





This one's Drosera lanata.

[Tacks]

Great idea for a thread! I've been interested in Petiolaris sundews since I saw the picture of D. derbyensis on the Wikipedia page on sundews, but I've held off as I try to get better at growing the easier subtropical species. I am looking at building a couple new grow spaces soon though, and something geared toward the Petiolaris group is at the top of my list.

Could you describe your setup in more detail? I'm particularly curious about your lighting, circulation (that looks like a computer fan on there) and supplemental heat (if any). Also I can't tell if you're using tray watering or not. Thanks a lot!

[jimscott]

Beautiful! Too bad you're in Canada...

[theplantman]

Great idea. I'd love to see information about: seed germination, guiding through dormancy, heat and cold tolerance, and perhaps where to even get some from. They seem impossible to find anywhere domestically.

[bluemax]

@Tacks: D. derbyensis is a beautiful plant. I still haven't seen that one in the flesh. As for the setup, sure thing. I think it could be done more simply but I have a tendency to deal with the variables one at a time. This produces a sort of piece-meal approach.

The lighting is 2 24" T5 florescent tubes with a reflector. Because it seems to cause the plants to lose their dew if the cover glass, which is just regular window glass, is allowed to get too hot the fixture is 3" - 4" above. I could use a bit more light for that reason.

Heating is provided by a heating mat, of the kind you use to germinate seeds, attached to the back of the tank behind the aluminum foil wrapped on 3 walls. There is also a low-wattage aquarium heater in a glass jar filled with water and a plastic lid to keep down evaporation. This heater uses only 7.5 watts and runs continuously without a thermostat. It is of the kind designed for small fish bowls. This is important because thermostatic heaters will heat the water in the jar to the preset temperature and then shut off. The room the tank is in becomes quite chilly in winter so I need the extra heat. I also have styrofoam insulation on the 3 walls with the foil to keep in the heat. In a warmer room a lot of this could be eliminated. I feel it is critical to keep the temps over 70F. and I prefer that they never get below 80F. A daily high in the 90's to low 100's is my aim.

The plants are indeed watered by tray. They sit on a raised egg crate platform that has water below it as well. The computer fan blows down through this and helps to raise the humidity while providing circulation. It was too powerful and created way too much air flow originally so I have cut off about 80% of the impeller blades.

I would love to know how others grow the petiolaris 'dews. There must be simpler ways.

@Jimscott: That's Vancouver, Washington State. We're across the Columbia River from Portland, Oregon.

[Tacks]

Cool, thanks for the detailed response! Gives me a lot to think about.

[bluemax]

What it all comes down to for me is the petiolaris sundews need all the regular things sundews need: relatively high light levels, lots of water and fairly standard Drosera soil. But what they need besides is humidity in the 70%+ levels and temperatures that never go below the 70's F., unless you are intentionally inducing dormancy. How you produce these conditions can vary a lot. In truly tropical climates they can be grown out of doors.

[Cindy]

This group of plants go dormant when the Australian summer hits them in the wild (like how pygmy sundews are dormant except autumn and winter) but they went dormant during the coolest months for me at the balcony. My ambient conditions ain't that different from where they originate from so I was confused.

Then I found out that they go dormant too during low light levels (usually the case for the year end months with loads of rain). And this dormancy often results in losses. Last year, I kept them going with high light levels under T5 lights. Seems to work so far.