Temperature and Spiking Experiment
 

I have a group of seedlings where a sibling has bloomed but the others haven't. The sibling bloomed in an environment where the average temperature didn't differ substantially - my house is heated to a consistent 70f. Upper temps reach about 79f under lights.
All of the siblings grow in exactly the same conditions.
Root and leaf growth is good. Size is good. The only apparent reason can therefore be that the required temperature stimulus has been absent. Any other potential reasons ? I am going to disregard the genetic component to this cross for the time being - in other words the species that make up this hybrid. Why ? because a sibling has already bloomed and this has never been mentioned as a factor in literature about this subject.
I placed this group in my basement on 20 February 2015. Temperatures in the basement only vary between 59 and 61f. Humidity varies between 45%-55%. I realise that there is no change in the average temperature with these temps - just interested in this experiment. Will the phals spike ? can they survive/grow on at 60f for an extended period ? This photo is taken today. I can detect no deterioration in the phals, they all still look good.
http://tapatalk.imageshack.com/v2/15...c1f48ddf71.jpg

This AOS paper might be helpful. I like the term: couch-potato orchds! ;-)

http://www.aos.org/images/img_conten...alaenopsis.pdf

If they are all mature enough and they have good light, I think the cooler temps could initiate spikes in some. I found when I keep my Phals in the greenhouse in fall and the temps drop to between 55F and 65F, that I get spikes after a month or so. However, I have kept several in the house near a window and seen the odd spike there too. It is a bit cooler at the window than the rest of the house with our cold winters.

there doesn't seem to be any hard and fast rules around spiking. I have some that spike regularly throughout the year regardless of season and temperature. So on the stubborn ones I had them outdoors for a while - one or 2 spiked. These are the ones that don't seem to want to spike at all, despite lush growth - time for the harsh treatment !

Late bloomers literally.

Everynight the room where my plants reside drops about 10 degrees. All my phals have buds. (except the one whose spike I cut, but it's now growing off the spike). Wonder if the temp drop does help.

I had a bunch of noid rescue Phals in a room that routinely saw night time temps in the low 50s with day time temps about 10-15° higher. I started with 10 last year and 6 made it. Some were really rough and were doomed anyway, but all things considered......

I too keep phals in the greenhouse all year round and when it gets a cold bump outside they start giving up spikes. the paphs do this too I found out. Most of my phals now have some stage of spike as do most of my paphs do from the past few months of erratic cold and hot spells. They have been during the year as warm as 99' and as cold as 45'. Phals are much hardier plants than most give them credit for, cept when they get too much water or come from Home depot :lol:

The cold does initiate spiking so with that in mind, being grown perennially in 60-61 degrees IMO you wont have many spikes. the odd spike here and there with very little consistency in them. Commercial phal greenhouses use finishing rooms at 55 degrees to initiate spikes on mature plants to have phals all year round. And there isnt any hard evidence?

I dont have many species. mostly hybrid phals as I feel for myself they are much easier to meet the cultural requirements in getting them to mature and spike on a regular basis....


:waving:twocents:
phals with spikes:biggrin:
http://rkidkelly.smugmug.com/Flowers..._142921-XL.jpg

Two observations:
1) In my experience, colder temps do initiate spikes. I mostly winter my phals in my unheated garage in winter here in LA. Temp can drop down to the 60s and as soon as that happens, they all spike, provided they are healthy of course.

2) My neighbor grows several mature phals on a tree stump in his garden. Occasionally winter nights can be as cold as 45F here, and it seems to do the orchids no harm. But he has his plants under a canopy, and they are sheltered from the winter rains. I suspect as long as they are dry, cold temperature is tolerated. I tried it once on a rescued noid phal, and it promptly rotted. I suspect I was keeping it too wet.

Thanks
Andrew

Good luck with this, I look forward to hearing about your results. I've got my twin keikis sitting side by side right in front of an east window. One bloomed months before the other. Then both the mother and the second bloomed around the same time. Being so close to a window they certainly get some cooler temps.

A separate suffering dehydrated Phal started a keiki on its spike months ago, but it hasn't yet grown any roots. It's maybe a foot from the window and now it appears the keiki is growing a spike!!! WHEN daytime temps are up (you know how it's been in the Midwest lately) but nights still down. So...who knows... Guess you'll see. ;)