Ah HAH! Where you are living plays no role in my analysis of the
situation, but that "minor detail" of the HPS lighting makes a big
difference!

As to the light versus temperature thing, you're right that at some point
it's just too cold, but growing most plants on the cool side of their normal
temperature range with high light levels will actually give fantastic
results. Not that I am capable of that on a regular basis, mind you...

--

Ray Barkalow - First Rays Orchids - www.firstrays.com
Plants, Supplies, Books, Artwork, and Lots of Free Info!
..
wrote in message
...
Ray,

Thanks for the comments.

Here in Vancouver BC if I would let the solar heat do my heating for
me during the winter I would be looking at growing just Cymbidiums and
even then marginally. As my gh is on the north side of the house, in
winter partially shaded by the house, on a property that is the second
highest point in Vancouver, you can see why I need to raise my
temperatures to some realistic figures Also I use HPS lights during
the winter. I agree with you that light is more important than
temperature except when the temperature is too low. If the plants are
too cold then no amount of light will make them grow.

The reason I want a programmable is that so I can set the max, but
more importantly the minimum temperature so in case it gets very cold
I can have three heaters running instead of just two as I do now using
single point thermostats and timers.



On Tue, 26 Oct 2004 17:34:14 -0400, "Ray"
wrote:

After more than 30 years of orchid growing, I still vote with "old-timers"
that taught me way-back-when, and support NOT artificially raising the
daytime temperature of greenhouses, but letting solar heat gain do the
work.

Light is a more important factor to healthy plant growth than is warmth.
Artificially warming the GH on gray days will result in leggy, soft growth
that in extreme cases cannot support its own weight, let alone that of
added
blossoms.

Save your money and buy a single-setpoint thermostat, set it to the
minimum
temperature you'd like your plants to experience, and let it go at that.