TRANSCRIPT
HOT! HOT! HOT!
Moderator: Marilyn Light
Wed, 9 Jun 99
Present were:
neil_502 (Kibbutz Kfar Hanassi, Israel)
jeanne23 (Queensland Australia)
peeteilis (Tom, Algonquin Island KY)
JanetteH (Pilot Mtn., NC)
MarilyninOttawa
Ann12 (Dallas TX)
jim4eq (Miami FL)
marylois (northwest Louisiana)
MerryJennifer (Coral Gables FL)
Fleur (Tasmania)
sym_wbs (Jeanne - New Orleans LA)
jfal1 (jfal1) (Jay - Key West FL)
jcy8s (John in Arcadia, CA)
fancyfarmer (Mary Lou - FL)
OrchidMagic (Glen in Gulfport, MS)
AORCHID (art, simpsonville sc)
MiamiBert
Jade from G R (Grand Rapids MI)
bradwinn (Brad Winnicki/Sault Ste. Marie,Mi.)
kbbarrett (southern CA)
zeynep3 (Wilmington NC)
poln8r (Robert from Long Beach, MS)
gaillevy (Boca Raton, FL)
marilyninOttawa
Hello everyone. In a few minutes we will begin the topic: 'Hot! Hot! Hot!'
I have had experience with tropical heat and temperate summer heat. Each of these climates offers different challenges. Usually it is too hot and we have to deal with the consequences in our collections. First of all, what is the best strategy to deal with heat? 1) Collect only warm-growing orchids? 2) Invest in cooling equipment (air conditioners, evaporative coolers, etc)? or 3) learn about how warm-growing orchids manage when it is hot, hot, hot?
JanetteH (Pilot Mtn., NC)
Marilyn, all of the above?
marylois
1 and 3, Marilyn *G*
neil_502 (Kibbutz Kfar Hanassi,Israel)
Up here in the Galilee it's been in the mid 30's (centigrade) for the last week!
jim4eq (everglades east)
D ne 1 and 3, about to do #2 before my drac's turn fang up ;~[
marilyninOttawa
There are no absolutes but it is helpful to start with warmth-loving orchids.
Ann12
The mistake I've just made is ordering an orchid before I researched it. I just found out that Oncidium phalaenopsis is a cool grower. It doesn't stand much of a chance here. It'll die as soon as it hears it's in Texas.
marilyninOttawa
Lets look at the ways and means of warmth-loving orchids that thrive in the heat.
fancyfarmer
I have a system of keeping up the air circulation, by the natural openness of my shadehouse and by having a fan running day and night. I also can cool things down when necessary by some misting.
marilyninOttawa
First of all, it is a common assumption that tropical orchids grow in full sun. They may be exposed to the sky, it is true, but there may be only a few ours of direct sunshine a day. Most of the time it is cloudy. Orchids, even heat-loving ones, must have sep away heated air from around the growing plants. Air movement refreshes the orchid environment.
kbbarrett
Marilyn, what humidistat do you use? Do you prefer a thermostat with a remote bulb sensor?
peeteilis (still inky)
For those who still shade the whole house, it makes a difference where you spray the shading. If you spray it on the inside the house will be hot because the sun will heat the glass. If the shade is on the outside the house will be
cooler, summer AND winter!
kbbarrett
I find that in spite of my damping down the floor, the fogger on a humidistat, misters on timers and a swamp cooler the GH stays dry, so I was thinking there's an inherent error in the humidity gauge, it reads high, any thoughts as to how to verify GH humidity?
marilyninOttawa
Charley's stocks an English Compressed Air Sprayer - 1.5 gallon, $45. Visit their site
.
poln8r (Robert from Long Beach, MS)
Kathy, if you can borrow a sling psychrometer from someone (high schools and colleges usually have a few hanging around), they're pretty easy to use to get relative humidity.
JCY8S (John in Arcadia, CA)
Kathy, I think that your scale must be wrong. However I also have a lot of plants under the benches - not orchids but the ground is covered with selaginella (sp?) which is like a baby tears but not as invasive. That is constantly wet and sure helps the humidity. I once had a layer of pea sized lava rock 3 inches deep on the floor and that was great.
marilyninOttawa
Lois, when you have high humidity it is difficult to get evaporation let alone evaporative cooling. The best one can do is move the air and arrange the shading/roof high enough that the sun's heat does not overheat the orchids. Use mounts and very open mix for plants in containers. I understand about the ground being wet. All the more reason for a gravel base.
MiamiBert
Radio Shack has a very reliable electronic humidity gauge - quite cheap - around $25 - also records high/low humidity as well as high/low temp.
marylois (TOPIC: HOT! HOT! HOT! with Marilyn Light):
Marilyn, somehow between the cool wall and the high humidity, those 100 days never went over 85.
kbbarrett
Bert, I have those. Mine have been doused many times and I now wonder about their accuracy...
marilyninOttawa
In winter, under lights, I use two sonic misters to humidify the air. These of course have humidistats and I adjust them so as to have what the books refer to as a buoyant atmosphere. I have measured 50-60% Relative Humidity which is about as much as I dare maintain given that I do not want the walls of my house to become a still. In summer, the humidity is much determined by the weather. I mist regularly, more so on hot days and not at all on overcast or coolish days.
marilyninOttawa
Kathy. I was referring earlier to electronic thermometer to measure min/max temperatures in a growing area. These instruments are cheap, use a couple of AA batteries and last well if one takes care not to get the body wet. When we use a thermostat to monitor temperature so that vents can be opened or misters turned on then the sensor should be located where it can do the best job. Probably a few feet above the orchids would be the best location although you might wish to experiment.
Humidistats can malfunction.. Humidity is a relative measurement depending upon the air temperature and the amount of water the air can hold at a particular temperature. Where is your controlling device located? If it is in the cool end of the greenhouse then the relative humidity will read higher than in the warmer part.
marylois (TOPIC: HOT! HOT! HOT! with Marilyn Light)
My humidistats - one on each side of GH sit about midway on the side benches...I pick them up before watering and put back when I leave.
JCY8S (John in Arcadia, CA)
I have my humistat wall mounted on an upright on the side of my GH about 4 feet from the side wall.
kbbarrett
Marilyn, I have 3 of the Radio Shack gauges scattered around the GH. One in the shade, one in the sun and one near the floor. I have another electonic type hanging high up. I just have a hard time believing that the GH can 'read' 60% humidity, yet smell dry to my nose. And the floor is dry to my eye within hours of being damped down. I'll damp it down in the AM before I go to work, and when I come home for lunch its dry dry dry. Surely it wouldn't evaporate that quickly in 60% humidity??? I don't know.
marylois (TOPIC: HOT! HOT! HOT! with Marilyn Light)
Isn't ideal humidity between 60 and 80?
Clare in LA (Oops ,$80 million!)
So, now I have happy orchids in high heat with good air circulation and decent humidity. Winter comes and it's dry and 50. Is it as simple as heaters and misters still?
marylois (TOPIC: HOT! HOT! HOT! with Marilyn Light)
I'm just as wet in winter cause I have hot water heating - doesn't evaporate the inside of the GH. Those with too low humidity could consider putting in a 3-4 inch layer of gravel and cover it up with sand - Robert wanted sand on top to keep gravel from 'traveling' - then he put in wood slat walkways (which are being replaced as they rot!).
A friend across the border in east Texas custom built his GH (the pyramid GH featured in 'Orchids' a couple years back - seems to be IDEAL for growing - all heat goes up and the top of the pyramid opens - has HUGE fan up there to draw it out if opening alone doesn't do the job. Three walls are cool walls...plants are benched over concrete troughs filled with water! Pyramid shape makes air movement more controllable and light comes in evenly from all sides. She is growing tremendous things.
marilyninOttawa
Clare. I believe that the 'trick' if you wish lies in choosing plants that can best make the transition from hot humid to cool dry. We can grow seasonal types that naturally make the transition with a little help from us or we can grow orchids that by virtue of their growth habit do well in either situation. I am thinking of Paphs in particular. I don't think that Phals and Vandas make the transition very well. They get to like the summer and then winter comes! I find Catasetums make the transition well. Plants that can be kept quite wet also make the transition well.
Clare in LA (poor, but still happy.)
I do agree with that, Marilyn. We always tend to want to grow orchids that cannot be given optimum conditions. I find it to be a real trial and error and sometimes I can be quite surprised. Thanks for your time and knowledge.
marilyninOttawa
Good night everyone. Thank you for the great comments and discussion.
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