"Kenni Judd" wrote in message
. ..
Manelli Family: It's the "cover overhead" that Bill objects to, and he
has some very valid points, altho there are other issues to consider.

The cover overhead increases solar loading, and therefore heat inside the
shadehouse, even when all the sides are open. This is inescapable, short
of ditching the roof, and it causes me not to grow anything but the most
heat-tolerant orchids -- unless they are cold-hardy enough to stay out all
winter in the one "uncovered" shadehouse that we have -- we are too busy
to be carting plants in and out all the time during winter, which is our
busiest sales season). And I do have to take some measures to cool things
down (exhaust fans and overhead misters) in summer, which does make FPL
happy.

But without it:

1. It is indeed very difficult to heat for winter -- and yes, we have to
do that here, at least enough so I DO notice the gas bill. We heat to 55F
for our vandas, evergreen dendrobiums, and buds on all genera that we grow
(not a concern for Bill given his specialization in the intergeneric
Oncids, few of which would complain at high 30s, but do hate high heat).
With a small shadehouse in the home setting, this may not be as much of a
priority -- you could roll out a sheet of plastic as needed and tie it
down, or even bring the tender stuff into the house at need. That's what
we used to do when we were growing in a 15' x 15' "hobbyhouse" less than
12' tall. We had it set up much like opening or closing the drapes in
one's home. We also had a heating element that fit on the type of small
propane tank that one uses for a BBQ grill, and only needed one for the
whole little house. Those measures don't work so well with a much
taller 10K sq. ft. to cover and uncover.

2. You cannot control your watering. Where I am (a little over an hour
south of Bill), we get periods in summer where it rains quite heavily
every day for 2-3 weeks in a row. Some orchids like that, some will
tolerate it if you spray enough fungicide, and some just plain won't.
[Aother point not applicable to you home growers, but in a retail setting,
you're also effectively closed for business when it rains ... ].

Even in the home setting, whether or not to use the overhead cover depends
to a large extent on what you choose to grow, how you pot or mount them,
and other factors. This is something we discuss at length whenever
customers ask us to build a home shadehouse for them, to try to help them
make an informed decision.

Kenni

Very interesting. Thanks.



"Manelli Family" wrote in message
...

I wouldn't think anyone in a tropical climate would need or want a
greenhouse, even if they grew cacti. To protect them from the rain all
that would be needed is a cover overhead.