"Larry" wrote in
:

Hello. In the summer most of my orchids are outside in the screened-in
porch or hanging outside in trees. In the past I have moved the
plants indoors during the colder days. However, this year I bought
lighted shelving so they can be kept warmer outside. I also purchased
a vinyl tent that covers the whole unit.

Question: I live in Jacksonville, FL, and it does get cold at night
during the winters (for example, down to mid-upper 20s tonight/now).
But, I don't think the current lights are not keeping the plants warm
enough as it gets that cold. The shelving has 3 light fixtures (1 per
shelve), using two, 40-watt wide spectrum lamps per fixture (go to
http://www.indoorgardensupplies.com, click on flora-carts, combo
BA3-SE2 at the bottom).

Any suggestions on how to keep them warmer within the shelving unit I
already have? Different bulbs?

What is the minimum temperature I should aim for? I remember hearing
55 degrees at one point but am not sure if this is true. I have
several different orchid varieties.

Thanks in advance!

Larry
laf_at_lwpes_dot_org



Larry I think you should start hauling them inside. I did a quick dirty
calculation on what I think you have and to keep the temperature in your
tent at 60 F with an outside temp in the low 20's you will need a heater of
at least 1200 watts with a thermostat.

I'm using a vinyl tent sise of 4x2x6 which has a surface area of 96 sq ft
with a temperature differance of 38 you will need 3648 btu's to heat and
that comes out to be a little over 1000 watts. that is if my math is right.
My experiance with off the shelf heaters like department stores have is
erratic because they have crude thermostats.
If you insist on heating then don't use any heater that glowes red or one
that is a radiant heater. One is a fire hazard and both will heat and or
cook things just in front of it. A ceramic heater with a fan will work
better yet one that oscillates so that the heat isn't consentrated in one
place all the time. The other choice would be a liquid filled baseboard
heater.
Remember the thermostats on these units have a wide hystorisis, humm, dead
zone? hystorisis meaning the area between heater turn on and heater turn
off. your home thermostat is typically 3 degrees but on thes units it could
be as high as 20 degrees. meaning you set it at 60 and the heater will turn
on at 50 and turn off at 70.

Now that I said all this I still think you should start hauling them
inside.

Dusty