Greenhouse advice sought from SoCal, Southwestern folks
 

Hi all:

I've been growing a handful of cattleyas under shade cloth for 10+ years now. I always intended to build a greenhouse (probably a kit, possibly the Harbor Freight one) but never felt I could swing the cost...but...I'm giving it serious thought now, especially after seeing a thread here on the board about Orchidbyte's 6'x8' backyard greenhouse, which looks great to me (I can't seem to add a link without the board rejecting my post, though?).

I'm in Los Angeles, so the problem is high summer heat and low humidity. Could anyone who has a hobby greenhouse in a hot, dry environment comment or give advice on their preferred cooling systems, misters/foggers, reflective shadecloth, etc? I know people do have orchid greenhouses here, I'm just having trouble finding info specific to this environment.

Also: can you comment on the monthly costs of running those systems? I'm under the impression that the cost of building the greenhouse itself will be a lot less than running all of the equipment...

Thanks, I appreciate it.

Consider a trial period with a hoop house built from 1" or thicker PVC irrigation pipe and landscape plastic. If you like it you can build something more permanent. Your weather is mild, so something like this will be fine. It might not require a building permit.

Evaporative coolers work well when humidity is low. Check your weather forecast. When the dew point is below 55 F they work well. They use water so rationing may be an issue.

Shade cloth will be mandatory. Not many orchids grow in full sun in habitat. Here in Phoenix many people use Aluminet, saying it helps reflect heat as well as light.

An electric space heater should suffice on cool winter nights. A fan running constantly is mandatory. Spring for a high quality temperature and humidity sensor.

^^ What he said...

I am in texas, hot and dry summers....I run a mister (jaybird 700) set on a humidistat, and an evaporative cooler....I had an extra humidistat so I put it on that as well...I think that it should actually be on a thermostat...that's in the works for next summer....lots of fans, and an exhaust fan larger than required working with passive intake shutters.....its a delicate balance here, as the summers can stay at over 100 degrees for days on end....evap coolers are inexpensive, and work great!

Ok, thanks for the responses. If anyone else has any thoughts/input I'd be grateful to hear them.

Can't help with the question, but to post links you need minimum 5 posts. One more post and you're good to go!

Ah, I see. Thanks!

hi darby, hows the plan coming?....I built my last couple greenhouses with cedar and polycarbonate....both lean-to designs I just made as I went, lol....I grabbed all the space I was allowed on our lots!
my bf is understanding what I used to say all the time, no matter how big it is, IT IS NEVER BIG ENOUGH! lol....
I had a couple in florida too, with double plastic, and that was always a mess....one with that corrugated stuff...the polycarb is definitely the way to go!
cedar wood is good to work with, for me anyway...it smells nice, and is easy to cut...I like screwing things together as it is more secure...
if you bide your time and wait for sales, the polycarb isn't that expensive....
good luck and let us see photos of your job!

I cool my little GH (was a kit, put it up about 10 years ago) with an Aquafog 700 fogger on a thermostat. (I live in Costa Mesa) It works beautifully - temperature rarely goes much above 85-90 deg F. (Our relatively low humidity makes it quite efficient) I also use a direct-vent gas heater (costs more than an electric one but costs A LOT less to operate) I did that after fighting to maintain temperature in the great freeze of 2006-2007, where I found that the most efficient 1500W 110v heater could not keep up when temps dropped to the low 30's F. Fans are the cheapies from Home Depot that are Vornado copies (cost about 1/3 as much) They last 2-3 years, the expensive ones don't last much longer. So go cheap.

Hi, thanks for checking in--well, the plan's coming very slowly, between various projects/life/etc. But now I'm trying to make some progress.

I've also been trying to figure out if a small greenhouse or an indoor orchidarium makes more sense, though I'm still leaning towards a greenhouse. This is all complicated by the fact that the only space I have to build on is on a 6" thick concrete slab (that can't be easily/cheaply removed without a jackhammer) and so I won't be able to bury water/power lines and have to bring in water via hose from a distant spigot. I'm not sure if that qualifies as a 'problem' or not.

I'm interested in your cedar/polycarb greenhouse, do you happen to have any build pictures by any chance? I assumed a kit would be cheaper to build in the end...but I have built a shed that's still standing and I'm not afraid to try going DIY. I can screw things together with the best of them...

---------- Post added at 06:14 PM ---------- Previous post was at 06:02 PM ----------

Thanks for your note--does the Aquafog qualify as an evaporative cooler? I wasn't clear on that based on briefly looking at its description online. My impression from doing research on the forum here is that I'll need a combination of evaporative cooling and a fogging system. Do you use the Aquafog mainly for temperature control, or does it also help raise the humidity?

Heating, I haven't given it as much thought as I probably should. Since it usually doesn't freeze here I tend to be a bit complacent--but during the big 2006/07 freeze I happened to be out of town and overnight went from a collection of 40 orchids growing outdoors down to, I think, 4.

The upside of that was that I learned which ones are the hardiest.