What's more important, heat or light?
 

Hi!

I'm just wondering what's more important to a Phal orhid, heat or light?

I have a room with a windowsill which gets a fair amount of light, but it's a much colder room.

Or I have a room which is much warmer, but the only surface available for the orchid just doesn't get as much natural light. Though the room's used more often so it would get more artificial light in the evenings.

As it's winter at the moment, and the plant has finished flowering, been repotted and I want to encourage the roots to grow, I'm not sure what to do for the best...

what is the phal ? There is no one rule for all.
Phal Wilsonii hybrids for example prefer it cooler with less light. Violacea hybrids prefer it warmer with less light.

Both? But probably heat for the general Phal, as I assume you don't have one of the more picky species or similar hybrids. If its a NoID, I'd stay with earth, especially since you recently repotted, and these mass produced plants don't mind lower light. But if you want it to do best, gotta provide both.

Hi, Seeing as you are in the UK, there's probably not much daylight this time year. As long as your room with the window doesn't go below 14-16 C. your phal will survive. Cool temps tend to stall them but it will bounce back once it starts warming up. They are tropical plants and really prefer it warm, but if your choice is light or heat I would choose light. Your warmer room with the normal lights won't be enough light for them to grow. You could also get a heat mat to place under them to keep the roots warmer.
I let my phals get down to 14C in winter with no ill effects other than they stop growing at the normal rate.

Bill

What is your cold room temp? Cold and warm have very different meanings which is why you will see the degrees always following the cold or warm statement.

If the cooler room is above about 15C then I would go for that and get the light. I've had a couple of times that phals kept in low light but warm have suffered in the winter (basically in the UK in the winter they need to be in a window as light levels are low anyway so if not in the window are too low).

I wouldn't expect growth at this time of year, they tend to go dormant with our low light levels and cooler temps. That's not a problem, it's good for them to rest. I would start expecting growth around early March.

Thanks for the answers. I don't know the type of Phal I'm afraid - it had pale yellow, plain flowers in the usual Phal formation, if that's any help.

And sadly yep, in the UK this time of year we do get very little light - and where I am it's mainly grey skies during the day!

I am a bit worried about temperature though, as I think the room could get below 14 C. This time of year, it can be nice and warm one day, but below freezing outside another.

How much damage would a sudden drop in temperature do?

Occasional drops in temperature should be OK, as long as they don't freeze, but it could struggle if constantly kept low. Keeping it drier will help when colder, it's likely to go dormant so it's even easier than usual to rot the roots.

A heat mat (a seedling mat) will likely help. I keep some of mine that I know struggle more in the winter on one and it certainly helps.

Your Phal is likely a common hybrid if you bought it in a supermarket or garden center in the UK. These have pretty middle of the road Phal care, generally heavily crossed hybrids like these have a wider range of conditions they are happy with.

Thanks for the answers everyone, you've been very helpful. :D

Mine was bought from Marks and Spencers, so I definitely think it's a common hybrid.

I'll try leaving it in the cooler room on the windowsill. I haven't got a thermometer to be able to give the temperatures though I'm afraid.

How adverse are these types of Phals to being moved? Like if it was going to be a very cold night, would it help to bring it into the warmer room for a bit?

I think these worry less about being moved than some types. The most likely adverse affect from moving it would be bud blast (when the flowers or bud drop before they should). The plant it's self would be fine. I move mine around quite regularly, although when in flower less so, but my rooms are all about the same temperature (apart from one where I keep cooler loving orchids). It's the change in conditions that can cause bud blast. Some phals would cope fine, it's difficult to say I'm afraid. Unless it was getting really cold I would probably not move it if in flower.