The Orchid Source - Orchid Forum

I have started construction on my greenhouse, its a 12 x 12x x 8 wood frame greenhouse with an 11 foot center. I finished digging the base yesterday but I am at a standstill right now as we have a 20 to 80 percent chance of rain for the next 10 days so I cannot level the base and mortar the cinder blocks together

Here are some models of what the greenhouse will look like. The front and back will have a full glass/ retractable screen storm door and two double hung windows. The sides will have 4 double hung windows.

Good luck with the construction! Don't forget the adage to measure twice and cut once!

Good suggestion Pook! But, my dad was a carpenter and he always said measure it 3 times to be safe. Insurance for brain farts I guess.

I look forward to your work in progress. I was wondering how many orchids do you estimate that will be able to fit in your greenhouse?
What did you select for ventilation? Good luck, I'm sure it will be fabulous!

Well I have just under 200, so they all need to fit, i think they will or ill have to start dividing and selling some off. I plan on using a 16" exhaust fan, and two box fans on either side mounted as close to the top of the greenhouse as possible tor ventilation and air circulation. Eventually Ill upgrade the box fans

Trust me, dear, no matter how big you build, it won't be big enough!
Somehow having a gh just makes you buy more plants even if the
thing is full. I donno why!

I know, had a collection of over 400 but when I bought my house two years ago, I turned all my attention to that and sold off a lot of plants. I have not purchased any orchids in over two years until this week, but I was a plant that I had been looking for.

Congrats on getting this far, Kinte. I'm trying to work out plans for a small shade house I can enclose during extended periods of cold weather, for my orchids and tortoises, so it'll be as earth friendly as possible.

Kinte - can I make a suggestion: consider using ceiling fans for circulating the air. The down draft will certainly keep the air buoyant, and has the added advantage of drying crowns rapidly.

I first saw that up at Bloomfield orchids, and it worked really well.

Kinte,
If you have snails or slugs in the area you might want to consider a solid floor. I used a gravel floor and it is an ongoing battle

My favorite method: Measure once. Take a sip of beer. Measure twice. Take a second sip of beer. Check the measuring tape. Take a third sip of beer. Go find a shady place and a nice chair to think the whole thing over and enjoy the beer.

And with all that empty backyard space you can make it three times larger! You will not regret it, trust me.

'Just another opinion/observation:

Although, I've never been to Bloomfield Orchids and seen their set-up, I've had my own experience with ceiling fans in a greenhouse and I did not like them. Eventually, I tuned them off.

I used to be the grower at a nursery that had an orchid greenhouse that was 40' wide and 140' long.....and I guess the centre peak was about 20' high. There was an 8' wide aisle, off centre, down the length of the greenhouse with benches and narrower aisles radiating off the main aisle, perpendicular to it. There was a row of large ceiling fans directly over the main aisleway. The plants on the ends of the benches nearest the aisle were always too dry and anything hanging over the aisleway needed watering 3 times daily in the summer. The ceiling fans made a lot more work for me in terms of extra monitoring and watering....and many plants suffered over the long run as a result of the watering needs being neglected if there was a lot of customers to serve, or shows to travel to, etc.

I finally got my employer to buy and install a bunch of whisper quiet, commercial greenhouse 18" fans, mounted at the end of the smaller aisles, near the outside wall and blowing horizontally across the width of the greenhouse. Moving the air horizontally above and beside the plants worked MUCH better than blowing the air down on top of them.

It also had the benefit of NOT blowing the super heated air up in the peak down onto the plants in the summer. The cooler air, closer to the ground was all that what was being moved. The oven hot air in the peak was not being pushed down into the "grow zone".

Now, this being said, one thing that might work with ceiling fans is if the fan blades were turned, so that instead of only forcing the air down, they were "spinning" the air out horizontally more than pushing it down. Also, the use of mulitple fans would be better than just one. One fan will set up a continuous pattern of air flow in the same direction, affecting the same plants in the same way, all the time. This means that some plants will get too much air movement and some will not get enough. Spot watering of the dry places will be needed on a daily basis and it will become a chore. However, multiple fans will disturb each other's air flow patterns, introducing some chaos and random directionality to the air flow. This will provide lots of air movement all around the greenhouse; but, it will be more evenly distributed without so many "hot" and "cold" spots in terms of air movement.

You want the air to move the way water moves on a reef, near a shoreline. You want the air to flow in many different directions, in a rolling and tumbling fashion and you want it to be pretty much the same in all parts of the greenhouse, so that the plants all get the right amount of air movement. You don't want the air to move like water moves in a rushing river...always in the same direction, pounding some plants hard 24/7 and barely touching others.

This is VERY true!
I used to grow my hobby collection in a basement room that was 20' x 20' = 400 sq feet. I live in a farm house, so the basement has a cement floor and bare stone and mortar walls. I had 9,000 watts of fluorescent and HID lighting in there. There were 3 tiered shelves, 2' wide and 16' long along two walls, each with a four tube, 8' fluorescent fixture mounted above level 2 and level 3. The bottom level was for higher light, cooler growing things like Catts and they had 8 tubes, 8' long above them. The other two walls were covered in 1/2" chicken wire which was covered with mounted plants. The floor was covered in egg crating and hundreds more plants sat on top of that. The ceiling had 4, 400 watt HPS and 4, 400 watt MH lights. Everything was on timers along with an 18" exhaust fan on a thermostat. Plus, there were multiple fans, including oscillating ones to vary the air movement patterns 24/7. I watered with a garden hose and just allowed the runoff to flow across the bare floor and out, under the door to an outside drain. The room was PACKED with plants! Eventually, I built a greenhouse - 30' x 48' = 1,440 sq feet and moved all the plants into that. I closed down the orchid room and sold off the HID lights.

Within a year, I was back into the basement, running the lights again. I'd filled the greenhouse already! I seem to be a "plant packrat" and whenever I got interested in a new genus, I wouldn't let any of my other plants go!

Allison, my greenhouse has an earth floor and slugs were a major issue for me. Finally, I've found something that has stopped the little buggers dead! I use something called "Deadline MP". It's the usual Metaldehyde bait; but, it's delivered in a water resistent, extruded, bright blue mini pellet. It comes from a local grower/greenhouse supply company. I've never seen it for sale in retail stores. As a commercial grower, I can buy it from this company. They don't deal with the general public, just commercial growers; but, it's not something that requires me to have a pesticide licence to be able to purchase. You may be able to get it where you are at the retail level. If not, you may be able to get a grower supply place to sell you a bag....or maybe you could get a commercial grower to buy you a bag. It's expensive (about $250.00) for the large bag...I think it's 15 or 20 kg; but, it does a FANTASTIC job!!!!!

The problem with other slug bait is it washes away and/or rots before most of the slugs that are hiding in pots and in the gravel floor etc., come out and find the bait. This Deadline MP works so well because once I liberally spread it around my greenhouse, from wall to wall, it resists disolving and rotting for at least a couple of weeks. Even then, what rots away first is what's on the damp floor. Any pellets that are caught in leaf axis and on benches etc., lasts for a month or more. I NEVER have slug damage now...EVER!

I use it whenever I see a slug, or evidence of one, which is very rarely. When I see a slug....even just one, I treat the whole greenhouse (1,440 sq ft), with the amount that would fill a 1 1/2 gallon pot. I use a small scoop and starting at one end of the greenhouse, I fling the pellets up in the air and let them rain down on the benches and plants. I back up as I do this. By the time I reach the endwall, I've spread all the pellets and the whole greenhouse is covered in little blue pellets. Then, I don't see a slug or any slug damage again for about 6 months. At the first sign of a live slug, I do it again. This stuff has saved my business. At one point the slugs were winning and many plants that I was selling commercially were being returned!

Just google "Deadline MP" and you'll find info about it in the USA.

One note of caution: Because the bait is delivered in moisture resistent pellets, the poison is available and active for much longer than regular slug baits. That means children, pets and wildlife are at risk for a long time after you apply the pellets if they are allowed access to the growing area. 'Just something to keep in mind wherever this long lasting poison is used.

John,

The Bloomfield setup has the fans over the benches where they can do some good, not over the aisles. If I remember correctly, they are not up at the peak height, but on a level that is above head and outstretched arms.

Seems to me that if that grower let the peak of his greenhouse get that hot in the summer, he wasn't shading or ventilating properly.

Your suggestion of having the fan blades be a sideways "paddle" made me wonder: it used to be that pretty much any greenhouse you went into had "turbulator" fans, but I cannot recall the last time I saw one in use. What happened to them?

When I built my small greenhouse ten years ago, I dug a 12" deep trench and buried the bottom of the fiberglass sheathing all around. That has discouraged creepy crawlies, slimy crawlies and burrowing rodents. Not saying they can't get in, but it does stop access to a degree and keeps the problem controllable. I have a dirt/gravel/concrete paver floor and treat for slugs just as the weather cools in the fall each year and condensation starts to form on the walls from the cooler outside temps . The timing seems to be important down here for some reason. Don't see many slugs the rest of the year.

A turbulator for a hobby-sized GH would be a blessing, but they were big and dangerous, as they never had any protection from the blades.

I have two horizontal recirculation fans in opposite corners of the GH. Together they keep a steady, tumbling circulation going. Mounted plants and hanging baskets add to the turbulence.

Frankly, they are too big for theis structure, and running them at full speed would require me to fly some small craft advisory flags, but a fan speed controller really helps me "tune" the breeze. AND, if I water and the plants aren't drying fast enough, I can crank 'em up.

Perhaps that's why we don't see them anymore. I know that the two that we had where I worked were pretty scary......if you were careless enough to get too close. We had 2 open houses per year, where we let the public into this "growing greenhouse". I always turned the turbulators off. I could just see some father with a kid on his shoulders........! *Chills!*

Foundation was poured yesterday, and the cinder blocks were laid this am, this afternoon the cells will be filled and the anchor bolts placed.

The floor is leveled, pvc for water and electric are ready, the weed barrier is down and I have filled all the gaps with expandable foam where I but the base wood plate down. I think I am going to put the gravel in before I complete all the sides so its easier to get in the greenhouse.

I got the front framed today, ill do the back tomorrow and maybe one of the sides and finish off framing this weekend

Oh and let me tell you WARPING WOOD SUCKS!!!!!!!!!

Oh happy days cool. Bet you're getting excited!! How come the posts go up above the frame though? That's not what your drawing looked like. You gonna cut those off?