Tough love for phal seedlings?

[ALToronto]

I deflasked two phal hybrids last July, so this is their first winter. I have them on a south facing windowsill with a big tree in front, so it's not too sunny. I have two CFL bulbs about 60 cm above them (2'). During the day, if it's sunny, the temperature can reach 23-25 degrees, but as soon as the sunshine disappears, it drops to 17-18 during the day, 16 at night. 16 = 61F.

Some compots are growing very well, the plants have large thick leaves and plenty of new roots. But a few compots are at best stagnating, and two (out of 20) have no plants with any chance of survival under the current conditions.

I'm sure that if I moved the struggling plants into a warmer area, they would likely resume growing and may well end up as healthy mature plants. But if I leave them on the chilly windowsill, and only the fittest survive, am I practising natural selection for northern winters, or unnecessarily dooming otherwise viable plants to certain death? If the weaklings reached maturity, would they be just as hardy as my current strong growers?

Current wisdom says to keep seedlings warm. By keeping them under less than ideal conditions, am I benefitting the surviving population, or simply reducing it?

 

[NYEric]

Phals like warm and shady. If you want to torture them, have fun! Sadiste!! oke:

 

[gonewild]

Phals need temp above 27c to be in a vegetative phase. Below that temp they are in a reproductive phase. So trying to grow small seedlings at cool temps is counter productive.... slow decline.

 

[ALToronto]

But that's just it, Lance - a lot of them are not declining, but growing new roots and leaves - although much slower than they did in the summer. I don't mind a slowdown, if it means that they get used to cold temperatures and don't mind them so much later on.

So my question is still - am I developing hardier plants, or am I simply torturing them, as Eric suggests? I keep thinking about the (possibly apocryphal) native Indian tradition of dunking a newborn baby in ice water. Survival of the fittest taken to an extreme.

 

[gonewild]

You are not developing hardier plants.
You are torturing them BUT the survivors of the process would be the ones you would use as parents if your goal was to develop a strain of cold tolerant plants.

The temperature is warm enough for Phals to grow but the problem is as they reach maturity (age) they will produce flower spikes too quickly on small plants and the resulting flowers and flower stems will be small. You will not see the quality the hybrid is capable of if grown at the warmer temperatures while in the growth phase and then allowed a cool flowering phase.

Back in the 70's I tried to do exactly what you are thinking of. I grew out a house of Phal hybrids at very cool temps and bred the selected survivors. Eventually the percentage of survivors increased but still the quality was much better when the grow temperature was increased. So in reality the hybrid selection to include cold tolerance has been done many generations ago, perhaps that is why some of your seedlings are still alive and grow better than others.

You also have to consider the species within the genetic chain as temperature tolerance varies from species to species. For example I think Doritinopsis tolerate lower temperatures if I remember correctly.

If you continue growing your seedlings under the conditions the survivors will be more cold tolerant (forever) and perhaps that is what you want, a few good cool tolerant plants rather than 100% survival of the seedlings.

 

[NYEric]

I keep thinking about the (possibly apocryphal) native Indian tradition of dunking a newborn baby in ice water. Survival of the fittest taken to an extreme.

Very Spartan of you!

 

[ALToronto]

Very Spartan of you!

I guess I have my ancient cultures a little mixed up.

Lance, this is exactly the degree of detail I was hoping for in a response. It wasn't the response I was hoping for, but I guess I know what I'm dealing with now.

Next question: if phals grown at cool temps tend to produce smaller flowers, does this hold for phals that had been grown initially in warm conditions and then moved to, say, my house? In other words, will the mature phal hybrids that I currently have (that were mature when I bought them, and had been grown in warm greenhouses) produce smaller and smaller flowers?

I guess when my heated shelf unit is ready, the seedlings will be its first tenants.

 

[gonewild]

Next question: if phals grown at cool temps tend to produce smaller flowers, does this hold for phals that had been grown initially in warm conditions and then moved to, say, my house?

No. Plants grown at warm temperatures above 28c grow fast and big and strong make strong mature growths because they are not thinking about flowering. When the temp drops below 27c the plants rest a little and after a month or so the strong plant initiates a flower spike to become reproductive. Ideally after the spikes emerge a higher temperature will wake the plant up and it will put a lot of energy into the flower spike and more and bigger flowers result. .... repeating this cycle is how you will get the bigges and best display of flowers.

Now when you move a mature plant from a warm greenhouse to your cool house it will go into the reproductive phase and bloom with good flower production 9but not as much as if it were warmer). But if you leave the mature plant in the cool temperature it will keep thinking it is reproductive and keep producing flower spikes. It will continue to grow leaves but not as strong and as big as if the temperature was warmer. I suppose over time it might wear out or find a happy point where it grows slow and blooms a lot but with smaller flower displays.

When you start out with the small immature seedlings in the cool temperature the kids start thinking about reproduction at too early of an age. As soon as possible they make a flower spike at the sacrifice of becoming a physically strong adult. But they bloom a lot, just never amount to much or certainly do not mature to their full potential. Maybe in this regard Phals and people have something in common?

In other words, will the mature phal hybrids that I currently have (that were mature when I bought them, and had been grown in warm greenhouses) produce smaller and smaller flowers?

They probably will even out and not just continue to get smaller and smaller since they were mature before they first flowered.

I guess when my heated shelf unit is ready, the seedlings will be its first tenants.

:clap:

 

[Ozpaph]

I grow a few phals outside all year round. In winter it gets down to 10-13C at night. They dont die but they dont resume growing until well into spring.
I would grow them as warm as I can to get them to flower faster so you can keep the best and ditch the rest.

 

[gonewild]

I grow a few phals outside all year round. In winter it gets down to 10-13C at night. They dont die but they dont resume growing until well into spring.
I would grow them as warm as I can to get them to flower faster so you can keep the best and ditch the rest.

What is the low temperatures during the warm season?

 

[ALToronto]

Here it doesn't get below 20 during the summer. If we get some cool nights, I just close the windows and keep the plants warm. No problems at all keeping the temps up in the summer - I don't let my husband turn on the A/C unless it gets above 29. And then only to drop it to 26 or so.

 

[Ozpaph]

What is the low temperatures during the warm season?

around 20C