Dormancy for hot climates

[scottychaos]

I just got a PM from a PFT member, asking how one can do the "fridge method" if you live in a really warm climate..
and living in the "great white north" as I do, I dont really have a good answer!

in the very warm climate, you can still use the "fridge method" for the actual dormancy itself, but how can you prepare the plant for dormancy if your "autumn" stays in the 70's to 90's?!
Here in the north, we dont have that problem..autumn takes care of getting the plant "ready" naturally..autumn temps fall gradually through the 60's, 50's, 40's..then at the right time, the plant can go into the fridge, and its already dormant just from being outside until mid-October..

but..what can you do if you live in a tropical, very warm environment where nature cant do that job for you?
any ideas from the southerners here?
thanks,
Scot

 

[vistary]

Hi,
I stay in tropical Singapore, which is hot and wet throughout the year.( This is home to the neps)
I have been reasonably successful with VFT and their dormancy.
I purchase a wine cooler specially for dormancy purposes whereby I gradually lower the temp from 15C to 10C over a period of one month, hold it for 10C for another month and raise it back to 15C over the third month..
You can check out the dormancy section in my webpg for more info.

 

[Fygee]

I'm in a bit of a pickle with this as well. I live in Las Vegas where the Spring and Autumn times tend to be quite short before getting absurdly hot, or discomfortably cold.

 

[wickedthistle]

I have some probs as well, but here is what helps:
Move them to shade, indirect light only
Move them into your home, onto an indirect light windowsill
Move them in the the a cool bathroom or other spot in the house
THEN follow fridge dormancy suggestions (there is plenty info on the forums about this)

 

[Joseph Clemens]

<span style='font-size:11pt;line-height:100%'>Here in Tucson, Arizona I have not had a single problem with fridge dormancy. I either plant them in undrained containers I can put a lid on once they are submerged in water, before placing in the fridge, or I unpot them, wash most of any media off, trim off any remaining adult leaves, take a few old leaf basal pieces for propagation and then put them by variety/cultivar into individual zip loc bags with a couple of sprigs of just moist LFS.</span>

 

[Tamlin Dawnstar]

Remember initiation of dormancy is not really temperature related, it is a seasonal response to reduced photoperiod. The cold helps maintain the dormancy, but the actual cue is the shorter days. Plants without supplemental light will go dormant, and the remainder of the trick is to keep them so.

 

[The Griffin]

True, but if you have them in a fridge and it stops working, the little buggers will start sprouting white, etiolated shoots in response to the non-cold temps.

Cheers,

Joe

 

[scottychaos]

hmmmm..
I still dont buy the theory that photoperiod is more imortant than low temps..
sure, both play a part, but I think low temps are MUCH more imortant than decreased photoperiod for starting and holding dormancy..

look at 2 theoritical examples..
1. a VFT in a windowsill.
it gets no artificial light, only recieves window light.
in the late summer and early autumn the plant gets the decreased photoperiod, same as any plant outdoors.
but it does NOT get lower temps, because its indoors, and is subject to the constant 72 degrees that the resident humans enjoy.
So, decreased photoperiod, but no decreased temp..
will the plant go dormant?
no..not really.
it might slow down..it might some "dormancy cues" from the decreasing photoperiod..but..the constant warm temps will keep it growing..
its too warm for dormancy!
basically, the plant thinks its still summer but its not getting as much light..

example two.
another VFT.
lets say its in a terrarium outside.
lit artificially by a timer..
in the late summer it is subject to lower temps but its photoperiod never changes..
lower temps, constant lighting..
will it go dormant?
probably!
even if the light levels stay the same, if its 35 degrees its not going to be actively growing!
sure, it might be a bit confused by all the light, but the cold is going to force it into dormancy..


sure, I agree that having both less light AND lower temps is ideal.
and that is what most of us give out plants in the winter..
but it just seems logical to me that low temps would obviously be MUCH more important than less light..

I base this on a local nursery that grows and sells bonsai.
one winter a few years ago they has a group of japanese maple bonsai they kept in the greenhouse all summer.
as autumn approached they forgot to put them outside..
natural lighting through the greenhouse glass.
by January the plants were still in full leaf!
the leaves had not changed colors and dropped..
photoperiod decreased, temperature didnt..
they looked terrible!
they looked very ill..downright tired.
but..they were NOT dormant! because it was still very warm!
they kept growing..they were missing one very important dormancy cue..temp.

yes, I agree that you need both.
but when talking about triggering dormancy in VFT's,
I think its VERY important to give them gradualy lowered temps through autumn.
If I had to choose one "factor" to help a plant go into winter dormancy,
I would consider lower temps far more important than less light..

less light + really warm = weak and confused plants, but not dormant.

high light + cold temps = less than ideal dormancy, but plants wont grow at 35 degrees, regardless of how much light there is..

less light + cold temps = ideal dormancy, obviously..

Scot

 

[Joseph Clemens]

<span style='font-size:11pt;line-height:100%'>You all can make it as difficult or complicated as you choose. I am too lazy to make it more complicated than necessary. I have been sticking my VFTs into my refrigerator a few months at a time for almost 30 years --- they don't seem to have a problem with it. I don't pick any particular time of year to do it either. Some of my VFTs are in there at almost any time, no matter the season. My VFTs don't seem to know any of that complicated stuff about gradually lower temps or shortening photoperiod. And, yes they continue to grow, gradually, no matter how cold or dark they are in the refrigerator. BTW in the wild they never actually seem to be 100% dormant, like, for instance, deciduous trees. Even in the wild, I've always seen them growing, though slower and smaller in the winter months.

Whenever they seem to slow their growth, I find that a stint in the cold / dark refrigerator seems to increase their subsequent vigor.

#*#*#*#*#*#*#*

BTW, logically what would you expect any plant to do when it starts getting less light and lower temperatures. Duh, it's gonna grow less and slower if it doesn't get knocked out of balance with its environment and adventitious organisms take it out.</span>

 

[Tamlin Dawnstar]

Not to raise this debate yet again, but I have a friend in Brazil growing these plants outdoors with no problems with winter lows in the 50Fs. They never really go dormant, just slow in growth and make smaller traps.

I guess the best course is to experiment and decide for yourself what works best for you. Mine are underwater at 35-45F.

 

[scottychaos]

Tamlin,
I like your underwater idea!
that would solve the fridge-fungus problem..
are they bare-root in water?
im wondering how it would work to bare-root all my plants and dump them in a giant bowl of water and put *that* in the fridge!
the bowl could be drained and refilled every few weeks..
of course, I dont care for bare-rooting every year because I think the plants do better if their roots are disturbed as little as possible..
but still, its a cool idea!
Scot

 

[jimscott]

I'm certainly no expert botanist, but just looking at what happens outside, light and temperature are the biggest piece of the pie chart. I'm sure that there are pther factors, like precipitation, but every year, temps go up and they come down. Photoperiod increases and decreases. Having said that, temperature waffles its way in one direction or the other, while photoperiod is consistently in one direction or the other - and I don't think cloudy days or sunny days has a significant impact. Photoperiod and temperature work together, seemingly like a check and balance.