Correct Temperature for Phal in S/H?

[zachkent29]

I'm getting ready to take a Phal that is currently in a bark mix into S/H. It has multiple new roots that have just started and I understood that this was the right time to move plants into S/H.

My only concern is the temperature. I've read many people say that the Phal's sometime struggle with the reduced temperature that S/H brings to the roots. What exactly is a good temperature? The plant sits in my window in Georgia and stays 80 degrees (Fahrenheit) during the day and 72 at night. The room has between 40% and 50% humidity and there is a ceiling fan always going.

The rooms stays about 72 degrees during winter days and 65 degrees at night.

Has anyone had success with Phal's in S/H at these temperatures without a heat mat?

[zxyqu]

Hey Zach, good luck with your S/H attempt. Living in Ga myself, those temps shouldn't be too terrible, but i would be careful in winter. The heat mat is recommended for transition to S/H, but is not required. In winter though, that 65 in the room will probably be 2-5 deg lower depending on how good your windows are, and in the 60 range the roots might not like it as much. I might consider a heatmat starting when it gets cooler, or increase the temp a bit so the plant doesn't see mid-lo 60's, as the cooling from S/H will bring the "feels like temp" down more than that.
Just my thoughts, hopefully Ray and others will chime in. That said, some Phals really love it, and don't miss a beat if transferred at the right time. I've also had a bit better success when adding a single top layer of river rock over the LECA pellets. This has helped new roots go down into the pot, seems to improve wicking a bit, and keeps the pellets from being flushed out when I water (a big plus). Just a thought to try if you want.

[emmastone]

The plant needs medium to bright light and immediate to cool temperatures in summer. they must have a cool dry winter to flower between 50° to 55° F (10° to 13° C) at night, while their daytime preference is 60° to 75° F (16° to 24° C) and little water. If temperatures exceed these recommendations for more than a brief period, the orchids will suffer. If the sunlight or artificial light is too bright, they can get sunburned—bleached areas that will soon turn black or brown. Orchids should not receive light for more than 14 hours a day. More than that will prevent them from blooming. My experience has also shown that too little light also harms orchids, so it has to be a fine balance.

[magicatt]

Mine get 72/74 degrees daytime in the winter and a little less at night. No heat mats. They are doing fine with new roots everywhere and new leaves as well. I live in the northern USA if that matters. I think yours will be fine down south.

[Bud]

I have successfully grown Phals on S/H withour heat mats because in winter my building have centralized heater that is constant 80F ....I have to put the plant near the half opened window at night to achieve 60F then close the window in the daytime to have 80F....the plant on S/H method and plants on claypots is only 3 to 5 degrees cooler than the plants in bark mix in plastic pots....

[zachkent29]

Thanks everyone! It seems that I should be okay then! I may get a heat mat just in case though.

[RosieC]

I do find that the roots in S/H struggle if it's too cold over the winter, however for flowering you do need a temperature dip. I've not found they need to go as low as Emmastone indicates, it's more a dip than an absolute temperature that's needed. Mine get between 58F and 66F in the winter and that is enough for flowering. However the roots of the S/H ones do struggle over the winter and I find a heat mat is a must to keep them going. I lost some S/H phals before I realised this and last year just saved some that were starting to go the same way by putting a heat mat under them.