what are optimal temps for deflasked phal seedlings?

I bought heat mats to give some botom heat to my seedlings, but since they are in the covered trays, temps inside trays can ocasionally go up to 29-30C, but most of the time are around 27C.
Is it too high?
What is the highest temperature they can handle?
And what temps would they prefer?
Thanks.

[Wild Orchid]

Originally Posted by orchideya

I bought heat mats to give some botom heat to my seedlings, but since they are in the covered trays, temps inside trays can ocasionally go up to 29-30C, but most of the time are around 27C.
Is it too high?
What is the highest temperature they can handle?
And what temps would they prefer?
Thanks.

Sorry, I don't have an answer to your question but have a related one - did you buy your heat mat in Canada? I've been trying to find one for a suitable price at Amazon and Ebay for the last 2 weeks yet the shipping prices just entirely kill any suitable deal.

Any tips are much, much appreciated.

WO

I bought from Amazon.ca.
I got two of these:
Hydrofarm Seedling Heat Mat 9X19.50: Amazon.ca: Home & Garden
and paid $18.75 to ship to Ottawa.

[Wild Orchid]

Thank you so much for your quick response.

Happy Growing!

[orchidsarefun]

I use a heating mat in Winter but I don't have the warm-loving plants/seedlings directly on the mat.
I have the mat on a wire shelf, then a paper towel ( to protect mat ), then eggcrate and then the plants spaced on the eggcrate.
Heat escapes and warms the plants on the shelf below and also heat escapes and warms the plants above the ones on the mat. The mat does get warm, you can feel the warm air above and below.
I am thinking of also putting the mat on a timer, so that it is only on in the evening/early morning. I did get an evaporative humidifier which also disperses the warm air so that it doesn't get too hot at any time.

My seedlings are in the humidity trays. Heat mats are on the ikea shelves:



I put folded towels between heat mats and trays to bring temps down a bit, but would like to know the optimal temps I should keep.
I can bring it down some more by placing the whole thing in the basement where it is considerably cooler.

I checked the web - Borneo has year round temps in the range of 28-32 C, but humidity is 80%. My humidity in the trays is 60-70%, so I wonder if 30 C with my humidity is too hot for them.
What do you think?

[orchidsarefun]

The towels will concentrate the heat ? The IKEA shelves are also "solid" and the bottom heat is not dissipating ? ( mat heats from both sides ? )
I use eggcrate as it allows the heat to circulate. If you stand your trays on something similar, that would be better ? You could also use a timer and monitor ( like 3hrs on and 3hrs off ) and work out that you don't go above the max temp. You have 2 separate areas, so you can experiment.

As to your questions - I don't know. Your seedlings are really doing well and that should be an indicator to you.

I had a compot of miltoniopsis and I was similarly concerned. The breeder told me x conditions at 3 months, but it turns out that y was better in my circumstances. I only figured that out by growing them out under the 2 conditions - a pain I know.

Let us know how things turn out.

Thank you for your input.
My seedlings were doing well without heat mats, but I noticed that the temps during night could go down to 21C, then I read about benefits of bottom heat and rushed to buy those mats.
Now, I hope it is not the case of "don't fix it if it wasn't broken". I hope to see even better growth.

[Rowangreen]

I have a mix of seedlings including some phals (heiroglyphica X Kenneth Schubert). I've been aiming at 22C, but it's varied between 26 and as low as 18. Phals have shown good growth since coming out of flask about a month ago! I do have a heat mat, but I've not been leaving it on as I've been worrying if it goes about 25!

Interesting if the phals could actually benifit from it being higher: but I guess I will keep things as they are as other seedlings might not apreciate it. I guess the temps you had before were definitely OK (maybe depending on what species or cross you have?) but if the information you have leads you to think higher will be better...

Re humidity: I had some advice from a real life expert that keeping the humidity high at first is very important. My trays seem to give 100% humidity, so I've been leaving the top off for some time and gradually increasing that: they are now doing all evening going down into the 60's. If yours have been out for a while I guess there's no problem, but I think I'd be cautious about extra heat if you can't maintain humidity with it?

[Ray]

Most phalaenopsis are truly "hot" growers that tolerate our home conditions.

You will find that they will thrive under your conditions.