I am making a greenhouse that will be 6 feet tall, 4 feet wide and just over 2 feet deep. For now it will only have 2 shelves but will have room for at least 1 more lower shelf. Is there any reason this won't work? I am going to encase it with clear vinyl unless someone thinks it is better to use the semi transparent plastic sheeting. Any other suggestion, tips and anythnig else anyone can add would be very helpful. I have never done this so all the advice I can get before I do this tonight or tomorrow is appreciated. One other question: How cold is too cold for outside temps to put seedling in the greenhouse to have reasonable success and not have the seedlings die over night?
You may want to put a vent somewhere so you can open it if it gets too hot and close when not warm enough. Somewhere mid to upper part of the greenhouse seeing how heat rises. Hope this helps a little.
Newgrown's tip on venting is an excellant one and should be incorporated into the design. An ideal place for them, if roof's to be an inverted "V" to shed water and snow, would be between the peak and top of sidewalls: would take some extra framing; vents could easily be held open with wooden stakes notched to do so. On your sheeting: do consider regular greenhouse covering over clear vinyl, something that allows light in, is highly durable and will last more than a few seasons. The clear vinyl will allow too much heat/light buildup that could cause burning of sweedlings; will begin deteriorating the first season; eventually will be a headache to keep up with. You might want to check Farm Wholesale (are in Oregon) @ www.farmwholesale.com and look at what they offer: I can attest to the fact their sheeting is excellant and EASY to handle/cut to dimensions. Take into consideration how much light is going to reach each tier daily, try to situate greenhouse in an east-west position rather than north-south: this will allow 3 tiers of plants access to good light. I'd say, that where you're located, plants can withstand NO LOWER than 50 degrees at night, and still flourish. Other alternative would be placing flat heat mats on shelves under trays, run them only nights for bottom heat: are inexpensive to buy and operate. If your greenhouse is to be set on a soil base, putting down black landscapers fabric under it will help the soil retain some of the day's heat, and that sure helps also. Have FUN and GROW ON!
That's the frame so far. Lots of room to put in more shelves but not gonna do it yet. Need to figure out the plastic first. I can not find any plastic sheeting yet that says it is for greenhouses specifically in my area so I may have to settle for something else.
Try Charlie's Greenhouse and Supply in Mount Vernon, Wash.. They can help you and if not, can give you some good tips on where to go/what to use.
