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Growing Rhubarb in Hawaii

Posted by jm82792 Hawaii (My Page) on
Tue, Oct 30, 12 at 2:45

I enjoy challenges, I have a small reef tank that I've kept for a few years, I've done aquaponics, I keep some orchids, carnivorous plants, and some other random plants(that get ignored time to time from my studies :/ ).
Yet until I tried rhubarb did I ever feel inclined to grow a cool weather plant in Hawaii(minus tuberous drosera,vsome highlander nepenthes, and heliamphora).
Rhubarb doesn't like the daily spikes of 85F along with nightly lows of 75F to 65F. Winters are wet, but I'm doubting growing them as an annual will suffice like they do in the south.

After some research I found that some commercial ventures are growing cool weather crops in Singapore by chilling the nutrient solution; chilling the root zone is all that is needed.

So I'm debating what to do next. I happened to have a dozen 3 watt Rebel ES 10,000K LEDs leftover from my reef light upgrade, a LED driver, and I can easily order an aluminum heatsink. Then I could have a 200 Watt MH equivalent light without heat in the garage so the plants don't get totally irradiated by the sun.

Chilling is somewhat interesting. I thought about evaporation for cooling but the RH gets too high. Right now I have a small 2inch stainless steel "pot" seated on a 96 watt peltier cooler + heatsink that's being driven at only 5 watts, it's staying at a cool 70F in 85F atmosphere.
If driven at it's full potential I'm guessing I could chill a 5 gallon tank if insulated with care.

Am I the only one that's wanted to grow rhubarb in a tropical climate? I know it sounds excessive, but I'm thinking I could keep it economical, and get a ton of growth.
But I've never grown rhubarb, I've only killed seedlings so far.


Follow-Up Postings:

RE: Growing Rhubarb in Hawaii

Well I have a rhubarb seedling in a 1 gallon DWC bucket with a 3 watt LED light. I'm using Flora Nova Grow at seedling srength, I have PH test strips, and a PPM/TDS meter that I use for my RO-DI unit. It's only been a day but it's growing well(there is some root growth, even without the chilling that was bringing it's roots down to 60F at times.) If that works I'll go from there, if chilling is needed I'll see what's required. Perhaps I can simply aim a fan at/in the tank if the temp is too high.
Although 1 gallon is miniscule in size, I'll if this works be upgrading to a 5 gallon bucket in the future.
I've been also a tad curious with growing Wasabi, getting an actual plant or seeds that need to be stratified isn't easy. But perhaps if the nutrient solution is chilled to 65F or so, along with following a few papers published on growing it I could succeed...

RE: Growing Rhubarb in Hawaii

It grows well with general hydroponics grow nutrient, I think I'm at 30 milliliters per 5 gallons, and I'd like to go higher but already burned the tips once. It's in a (80%?)shade cloth walled greenhouse with a 20% tinted clear roofed. So for now growth is great, this summer might require evaporation cooling of the nutrient, thankfully I doubt TEC cooling or compressor based cooling needs to be done.
One thing I need to do is transplant it from the 3" pot to a 5" pot but I think it's okay for now, since transplanting it will set it back a few weeks.

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