A question to those who grow Drosera under lighting

[Aza]

Hi

I have been growing Drosera for a little while now, but I am hoping for some advice to increase the amount of dew they have.
They are growing in 80% humidity and 70 degrees fahrenheit.
I think they are getting plenty of light, so I dont think that is an issue.

Here are some pics:

And here is how I would like them to look!
I realise everyone wants their Drosera to look like these, but I am just hoping for some suggestions to help achieve this

 

[kwende]

A couple things.

First, your plants - by no means - look unhealthy. So as far as the overall health of the plant (to me at least) they look like they're doing pretty okay.

Second, when seeing plants in the wild, they don't always look like the pristine or "ideal" pictures you provided for us. They can sometimes look kind of ratty having to deal with nature and so on; so on that front I wouldn't fret too much about it.

Third, while I have dews that do what you showed (that do have that much dew on them), I've also noticed that a quick spritzing with a water bottle will make them look as though they have twice the amount of dew on them. To that end, I'm not completely convinced some people don't fake out the photos.

And finally, to address your issue directly: while I'm not an expert by any means at Sundews, I have had immense luck with mine this year. Mine experience far less humidity than yours (somewhere between 30-40%) and have about the same temperatures you experience (70-80). My setup includes 4 T-8 (so very intense) lights about four inches from the plants. I keep water in the trays consistently (I never let the trays dry out).

Under this setup I seem to get a lot of dew on my plants. Here are a couple (not so good, but it's the ones I had with me at work) photos of the dew I tend to get:

Ultimately I think it comes down to a lot of variables, not withstanding the plants themselves. I have noticed my plants cycle a bit: sometimes they produce lots of dew and go wild, while other times they tend to slow down slightly. I don't think nature really cares too much about our preferences, she just does what she wants when she wants.

In my personal experience, feeding them frequently ( a couple times a month) and giving them plenty of water and TONS of light produce the best results. Humidity and the like tend to come in second.

 

[cpbobby]

1st q.....how long have they been under the lights? if not a long time then they may need to acclimate still. and how far are they away from them? if they are fairly close try moving them an inch or 2 further away....perhaps if they are too close the lighting may be evaporating the dew.

 

[Aza]

Thanks for your reply

The plants are definitely healthy and continue to keep growing nicely.
I currently use a humidifier to keep that humidity level, so do you think I should perhaps turn off the humidifier?
From what I have read, I thought the humidity was needed under intense lighting, which I assume I have because most of my Drosera are going very red.

"Humidity is important because it decreases transpiration/ water loss, allowing dew droplets to be larger. While humidity is not as important if there is no air movement, humidity can be very beneficial in higher temperatures, bright sunlight..."
Quoted from growsundews.com

Thanks

 

[Sundrew]

I think temperature may be an issue. I grow my sundews at 80+ temps constantly, and I often see the dew you pictured as optimum. The plants I leave outside, though, which in the fall saw 70F days, had markedly less dew. I would try to raise the temperature to 80F if you can, especially if you're growing tropicals/subtropicals.

 

[Aza]

I have had these plants a fair time now, I think they are settled.

They were 8 inches above the plants.
I increased the distance to 11 inches a few days ago, as I think they are getting plenty of light, due to how red the plants are turning.
My thinking was they were getting too much light, although with the humidity shouldn't they be fine?

 

[Aza]

I also have a piece of acrylic under the lights to block off the heat. Before I had this the temps were higher and they had even less dew than they have now.
It really does seem everyone has different experiences and conditions to get the best results.
However I have tried all sorts....with and without the acrylic, with and without the humidifier, and currently they seem the best they have been.

 

[Sundrew]

True, what works for me may not necessarily work for you. All I know is that with 60% RH, 80-85F temperatures, and 4 t12 bulbs 3 inches from the plants, I get this:

<a href="http://www.flickr.com/photos/84442298@N03/8080955201/" title="DSC01646 by Sundrew, on Flickr"><img src="http://farm9.staticflickr.com/8190/8080955201_7d0553db68_z.jpg" width="640" height="400" alt="DSC01646"></a>

 

[Aza]

Hehe fair enough! I shall give that a try
Should I see improvement quickly? Or are they likely to decline first before re-acclimatizing?

 

[Sundrew]

I'm not really sure. I'd expect a short acclimation period, but I don't think it should take long.

 

[Aza]

Thanks, I shall try to mimic your conditions and see what happens.

 

[kwende]

"While humidity is not as important if there is no air movement, humidity can be very beneficial in higher temperatures, bright sunlight..."

I have my plants in a terrarium and have had issues with fungus, etc. when the humidity levels were high and no air movement. Each person is a bit different due to their particular collection, plants and habits, but when I dropped the humidity, the fungus and whatnot went away. When my humidity was at 80% for a while, I was constantly scraping growth off the moss in the pots. Growing in a terrarium, I think it's definitely possible to have too much humidity due to the fact you don't have as much air movement.

To build atop Sundrew's comments....the evening temperatures of my plants drop into the 70s, but during the day they're at a steady 80-85. Perhaps temperature is more of an issue.

 

[Sundrew]

Oh ya! My basement is a solid 68F all the time. So they do have a considerable temperature drop in the evening.

 

[kwende]

Personally - I think that's a big component too. I have them in a sun room that doesn't have central heating, so it tends to get a bit chillier in the evening. I've done this by kind of studying the temperature trends in that room and realizing it's the most variable in the house (giving a good temperature gradient between day and night).

But it's worth noting that I still get periods of time (especially the hamiltonii) where the plants really don't produce great dew. It's cyclical, though. Because in a couple weeks they will go gangbusters.

But they flower constantly, feed constantly, and are constantly creating offshoots. So they seem happy (almost annoyingly so with the Capensis)

 

[Aza]

Thanks for all the advice, I appreciate it
I have made adjustments to my conditions to try and replicate what you guys are doing, so fingers crossed, they will start improving soon.

 

[Not a Number]

You don't say what your lighting is - type of tubes, color temps, number of tubes.

Coloration of plants is a function of color temperature, UV and intensity. Dew formation is more a function of intensity.

As long as the humidity is >30% most temperate and subtropical Drosera are happy.

You probably need to move them closer to the lights IMHO.

D. hamiltonii and D. slackii spend a good percentage of the time "dewless". They seem to have a very narrow "sweet spot". I wouldn't worry about those two.

 

[richjam1986]

It probably really will depend a little on the species as well. As the dew contains products of photosynthesis (resins, carbohydrates, etc, in addition to water), dew production will depend largely at what temperature each species has the highest rate of photosynthesis. More cool tolerant sundews will probably have better dew production in cool or moderate temps, while heat loving sundews will probably produce more dew in a higher temps. Good lighting in any case is obviously essential, and humidity may help, but put them in conditions closest to their natural habitat if you can, and that will probably give you the best results (though it requires a little more research)

 

[Aza]

I have 5x 2ft T5 sunblaster tubes. All 6400K which give 120W and 11,000 lumens.

 

[kwende]

I will mirror NaN regarding D. hamiltoni: it isn't a dew producer for me. Occasionally it'll produce, but for the most part it doesn't. I dust food on it periodically and it seems to be growing. I just let it sit. It does it's thing and seems happy.

 

[Keith]

I am new to this so not to be trusted but here's my 2 cents: The hamiltonii seems strangely colored almost as if it's getting a little more light than it was used to. My hamiltonii did something very similar earlier this year and I moved it a little further away from the lights and increased the water in the tray a little and it has had great dew ever since.
Also I was wondering about your soil mix? I made the mistake of using a highly refined sand in my mixes when I started out this year and it nearly wiped out my entire collection! The sand was very well washed before mixing and still for whatever reason I lost roots and whole plants left and right! Thank God for leaf cuttings! The source of my sand I can't confirm other than it is the sand usually used to "top-dress" golf course greens. The Superintendant assured me that the only thing added to this sand was a minimal amount of sphag peat and all that was washed out for sure when I washed it. I have had a hard time getting pH readings with my cheap meter due to the nature of the boggy soil, but I suspect that mineral content and pH must have had something to do with it.