Hi everybody. Another from-seed newbie here. My thing is native prennials, most of which I am lucky enough to already have growing on my property and need no "help" from me! I have had my eye on a few new ones ,though, and decided to give the seeding thing a try. I too have issues with the Jiffy greenhouse kit. I planted lobelia (cardinal flower), ironweed, and blue mist (conoclinium?) as well as a few odd rudbeckia, all about 10 days ago. I followed the directions on the package to the letter, and yesterday I discovered it is not a total loss as I noticed one single tiny seedling-the rest are all lifeless and most are grey and fuzzy. Trouble is, I contacted both the maufacturer 1-800 number AND a local greenhouse and the advice I got was ompletely opposite each other. Jiffy's rep said cover immediately with little or low light, while the greenhouse said they always put on light immediately after planting and left them open to the air. My pellets were not soggy after expanding but the mold still turned up after the second day. I'm pretty clueless which set of advice to follow, but thankfully I do have more seed held back in reserve. Any advice for this greenhorn? I guess I should stick to barerooting it....Embarrassing to think I killed ironweed! I am not sure, but none of the plants I mentioned need scarification or winter temps, do they? again, those were cardinal flower (lobelia), ironweed, rudbeckia and blue mist

A lot of good information already posted. I have been hearing more and more about pit style greenhouses that utilize the constant temperature of the ground of 50 degrees coupled with a greenhouse or hoophouse structure over top. I would like to incorporate decomposing horse manure with red worms to provide good humus for our garden and feeding the chickens in the winter with the worms. All structures degrade over time and the cost of the structure replacement should be considered. Obviously, you never know how long something is going to last, but there are good indications how long greenhouse plastic can last if you do your homework. Treated lumber on the ground can last a long time and can be shielded with plastic to help prevent leaching of the pressure treating chemicals in the soil. Another alternative to treated lumber is composite material (basically standard size 2 x material but plastic based). Constructing a greenhouse gives you an opportunity to build what you want and is easy to do, while saving you money. As you probably already know, orientation of the structure in relationship to the sun is important. Depending on what you grow, shade clothes can be beneficial as well. Very few times have I heard where heating a greenhouse with electric, gas, etc is cost effective. Instead, covering plants with a secondary cover within the greenhouse and utilizing a bowl or bucket of warm water during the night can be a great help. It is a little more work, but well worth the savings. Hope this helps a little. Mike's Plans

My BC is a 12 x 16 ft. "Anniversary" model and I chose both a white frame and curved roof for asthetic reasons, as it will be a feature in my garden. However, we often get heavy wet snows here, so having a roof that will encourage snow to slide off on its own may prove practical too. I ordered it with roof vents, then added 12" power vents and a fan that will be operated off a single line to a thermostat control. I was given to understand that white was better for very hot climates, but also know that deserts can get quite cool at night, so can't comment on which color might be best for you. But I would bet your local S&WCD and/or Univ. Ag. Extension people would, and if you aren't already in contact with them, you should, because few people can or will give you as much genuine expert counsel specific to your area weather and soil conditions for free. (Well, okay: not free, but you might as well get the most bang from your tax bucks.) I will also be installing a 52" ceiling fan, and with a 12" door drop, the roof purlins will be high enough to serve as braces for ceiling joists that will run across the width of the GH and serve as mounting frames for both the fan and lights that will be below the blades, to avoid the strobe effect. I will be heating with natural gas and will order my heater from ACF in the next week or so, but it will be a Sterling, upon the insistance of our H/AC pro., who it delcared superior to Modine, and it's tublar heat exchanger the best choice for a GH. We are constructing upon 2 high, 4 X 6 treated timbers, set upright on concrete footers, and will cap them with lengths of radius edged cedar 1 x 6s. We will miter the corners on the cedar, and router edge the ends by the door to match the outer edges. The cedar caps will extend out over the sides of the 4 x 6s, to form a sort of sill. I needed to come up with a means to get around the copper-alum. conflict, and the cedar cap will accomplish that goal while adding a nice finishing touch to the appearance of the base. I would have liked to go with Nathan's deep down foam scheme for insulation, but can't, so will use his under and out, with 2" Type 250 foam under the floor and 2" Type 150 against the inside of the base, down 3 ft., and out 2 ft. from the outside of the base. We are on hydric soil here and drainage is always a consideration, so we will slope the outside foam down a bit. Our water was already in place to a freeze proof garden faucet that will now be inside the GH, close to a 50 gal. sump pit with a pump, that will drain into a long, also below freeze line gray water drain. I haven't yet decided on a misting-drip system, as we are still in the construction phase of the foundation, but am planning water lines running the length of the GH, with Ts off to the sides every 4 ft. and down, to faucets set just above the plant tables. We thought about laying the water lines under the floor, but have decided not to, to keep them accessable. Ditto electrical lines. I HATE extension cords and will not have any, but also need to allow for plugs for tank heaters and lights and timers, as my GH will be as much a fish room as a plant haven. We will run 12-3 outdoor wire through pvc; the same for water and another for air, as my big air pumps run at least 3000 gallons each, so I'll likely have only one in service at a time. I bought a 5 gal. point of use electric water heater for my sink, which will be mounted on an 8 ft. wide cedar base against the back wall, above the sump. Our weather has been miserable for months, so it threw our schedule off, but we finally have the footers in and will cut the 4 x 6's tomorrow. Then, I get them stained, sealed and ready to bolt down. I'm still making decisions about some of the details, but know they will reveal themselves as we go, such as my need for shade cloths. But I was also determined to make the major decisions before we laid the foundation, as retrofitting is a PITA and at our age, time is the real enemy. One our heirs just called, to tell me to spend it, so I think I'll just order the vent and power intake screens and not drive my poor hubby nuts trying fabricate them. I too appreciate the comfort and insulating properties of rubber stall/trailer mats and thought of using them, but they are just too heavy for me to handle alone anymore, so will stick to lighter weight mats, like the foam ones that fit together like jigsaw puzzles. But I've also decided to use glazed quarry tile on the floor, laid on cement board atop the 2" Type 250 foam over about 6 inches of compacted limestone screenings, sloped a bit to a center floor drain, connected to the sump. I figured I might as well have my GH floor look as pretty and be as easy to keep clean as the mud room in the house and believe it or not; glazed quarry tile is cheaper than those cement patio pavers that crumble on the edges every time you step on them. You asked if my GH came with anything. It came with exactly what I ordered, but the best thing it came with may have been Kyle. I can't stress that enough, because if you read some of the posts about the problems so many people are having with mass produced erector sets from Harbor Freight, for me at least, being able to just ring up the mfg. has already made all the difference with what is after all, a rather complicated and somewhat pricey DIY project. If money were truly no object; I could have been in Aruba while a contractor did it all, then come home to a completed plant and fish palace. If you are asking for any advice, it would be for you to sit down and determine exactly how much you are prepared to spend on the total; then crunch your numbers to see what you must have to be able to use your GH, and what you simply want in addition, and decide which is which. If you rationalize it, a garden GH is a purely want, not a need, so when you are done, it should be whatever gives you the most pleasure your wallet can support. I recall the old joke about the fellow who goes to his garden center to buy everything he needs to grow tomatoes, from tools, bags of fancy soil, cages, fertilizer and tomato plants; spending a pile of $ in the process. As he is leaving, he asks the clerk when his tomatoes will be ready to eat, and the clerk replies: "Oh, right about when they will be Five Cents a pound at the farm stands."

I'm in zone 6 TN with even colder winters than you Texans. My house looks similar to the illustration except that below grade mine is good ol' Tennessee red clay rather than concrete, and the rafters are anchored directly to the ground. It was originally built as an experiment and considered temporary. I am in the process of making it permanent. Current dimensions are 14'x26', 9' at the ridge and 4' at the sides. The ground it sets on slopes, so the back end is 5' below grade and the front is 3.5' below grade. I am in the process of deepening and berming, and eventually it will be 6-8' below grade with a slightly sloping flat roof 6-8' above grade with headroom of 12-14'. I use it to overwinter a collection of palms and camellias and a few other plants that will not live outside over a TN winter without protection. Since having the greenhouse, our temps have been zone 7, most years falling to around 5F a few times. Most nights are in the 20'sF. I heat with a home type kero heater only when I think temps inside will drop below freezing. This has been 6-8 times per winter and costs per winter have been less than $100 with kero at $3.50 per gallon. Generally I think about heat when the temps fall to 15F. Depending on the weather, inside temps are usually 10-20F above outside. It has not been tested at negative numbers, and I will probably get another heater as a help when the inevitable happens. Our record low here has been -28F in '85, but I have seen temps in the negative teens several times since I have lived here (26 years) and expect to see temps like that again. I remove all plants around the end of April. I probably could do it earlier, but I am subject to late spring freezes and most stuff is in soft growth so I wait. Fall is usually friendlier and most stuff comes in by mid Nov. I use a residential type attic fan for ventilation, and that works well in all but summer. In summer with the fan going, temps stay about 15F above outside. The highest inside I've seen is 115F, generally 105-110F most sunny summer days. Water is a problem, and I will install a sump pump this fall. This past winter the greenhouse flooded at least 4 times. I am able to syphon the water so no harm done but it's a PITA. Dampness is rampant, especially with low inside temps and cloudy winter days. It does not affect my woody stuff, but I am unable to grow anything herbaceous like pansies. They melt from Botrytis. I keep a box fan mounted up high going 24/7. Currently I have electric run on the ground from my house which is 50' away, and drag a hose in for water. Eventually I will install 4" Schedule 40 from my basement and run electric, water, and hopefully gas to the greenhouse. I hope this info helps. I have no experience in zone 8a. I think my main concern would be winter wet. Ken