Sorry this may ramble a bit, but so much is going through my little head right now, I'm just letting it out as I think of it. This is bringing up lots of memories of when my dad started out with a small lean-to on the side of the house to sell tomato plants 35 years ago. That business grew several times until we had a single 40 X 50 greenhouse that took up the entire back yard. We now have 5 acres and multiple greenhouses at another location that I have run since 1997 and now produce and sell over 100,000 plants per season. So this is coming from a grower/retailer perspective. Check that you can sell items that aren't grown in your greenhouse. I have to grow 75% of what I sell on site in my zoning. Buy a greenhouse with the appropriate snow load/wind rating for your area. It doesn't take much wet snow to collapse a poorly designed greenhouse. I have two from a Canadian company-Harnois (the third is from a company that I think and hope are now out of business-they were awful to deal with). They were easy to put up and have worked great for us. The last one I bought (30 x 48-which probably the minimum you should consider) was about $7,000 nearly 10 years ago. This price included one heater and three roll up motors and two layers of plastic. I had to build my own end walls to save a little money but you can buy an endwall package separately. You will need electricity for the roll up vents (side and peak) and for the ignition for gas heater(s). But that requirement would be less than for exhaust fans for a ghs with no vents. I wouldn't risk my plants in somebody else's greenhouse that couldn't keep them heated if needed. Nor would I trust my hard work to a greenhouse made from PVC. You need one large enough that people can walk around comfortably and accommodate each vendor. Hoop houses generally don't have a lot of head room along the sides unless you get a high tunnel. If you expect the business to grow get a greenhouse that may be a little larger/wider than you think you need. Otherwise you will be replacing the small one real soon-kind of a waste of money. We went from lots of small greenhouses to a couple larger greenhouses to the single large house and now several large greenhouses. Buy something that is intended to be a greenhouse-you don't want to be jerry rigging something that might not work as expected. There are plenty of professional greenhouse manufacturers (Nexus, Atlas, Jaderloon, Conley, Harnois,etc) out there that will help you. They also will have the proper materials to use and be able to provide you with some guidance. You'll be much happier and the product will probably last a lot longer. Check out Greenhouse auction This is a past auction that still has 450,000 square feet of greenhouse left from a bankrupt nursery. They will arrange shipping for a fee. My hoop houses (20 x 48 & 17 x 48) are open at one end where I can pull the plastic up or lower it to get air and cool off the house. The other end has a regular sized door. The larger one is made so I can pull up the sides about 2 feet off the ground using ropes. Even when fully open, they get 100F + by late May or about 20-30ºF warmer than outside. I use these to hold plants-no customers allowed. Trust me, nobody wants to stay in those conditions for very long-customers or vendors. I also would be leery of the pest issue. Even if everyone has 100% pest free plants (extremely unlikely IMHO) you will get pests. Who will be responsible, and what kind of controls will you use? Preventative or curative? An ornamental grower will have different requirements than an a veggie or herb grower. You may have to have separate greenhouses and spray equipment etc. This idea opens you up to additional liability. If somebody else's plants are lost in your facility you'd better have insurance! Of course you should have insurance if the public will be on your property anyway (a hidden cost and a selling point to potential vendors) $25,000 is not a lot of money. You will run into lots of unexpected costs. Will you have to make other improvements to accommodate the public and vendors-like bathroom facilities? How quickly do you expect to get a return on your money? The people who you should listen to as far as the type of structure are the people who would be using it. What are their needs and concerns? Taking the plastic off in the winter raises a few comments/questions. I assume that you would recover in the late winter/early spring. I don't know about your area but in mine that time of the year is the worst time to try to stretch a huge piece of plastic because most days are breezy. It takes only the slightest breeze to fill a greenhouse cover like a giant sail. You have to do the job when there is no breeze otherwise, you will be miserable trying. It is also a job for several people. The larger the greenhouse the harder it is to cover. Although easier to cover a small greenhouse heats up extremely quickly and has other disadvantages as well. $10 a day is a lot to pay for a vendor-farmers markets in our area cost $50 for the whole season (May thru November, one day per week). Maybe you should charge for the whole season instead of by the day. Or do both but give a discount if they pay for the whole season up front. That gives them an additional incentive to show up everyday. You have to convince your vendors that you have something to offer for their money. And it needs to be something they can't do on their own and will make them money. Find out what they expect and need and then offer that to them. What would the advantage be to have their plants in your greenhouse if they have their own already. Is this advantage worth them paying a little extra money to you? Who will take care of promoting the market? Pay for advertising? Hope this helps!

You don't say were you live. So answering your concern is difficult. Even so, the creatures in the rootballs could have been springtails or other soil-dwelling critters. Then too, termite workers will die if they don't have a queen. I suggest you relax because I seriously doubt you inadvertently acquired termites. Because gardening is one of those live and learn sort of things, next time ask (w/ images, please) before you leap into action.

Here's a link that will give you lots of info on termites. It's the Louisiana State University Ag Center's website, so they talk specifically about the Formosan Subterrarean Termite. However, most of it applies to all subterranean termites (but not drywood termites). When you click on the link, you'll get a pop-up box asking for your zip code, but it's the only pop-up you'll get. If your house has a concrete foundation you should probably be more worried about cracked corners and the bath traps than the mulch. There are good pictures of both on the link I provided, so that you'll know what I'm talking about. The site says that mulch can be a problem if you put it on top of a treated termite barrier around your house because it can give the termites a bridge over the treatment. It can also be a problem against a foundation if it keeps you from seeing the termite tubes (which are not usually as large and dramatic as ones you see pictures of on the web). They recommend leaving 6 inches of your foundation showing so that you can inspect it easily for termite tubes. When you inspect your foundation, occasionally take a little spade and dig 6-10 inches down at key points (places where plumbing enters or exits your house, cracked corners, wood fence posts, wet areas, etc). Termites look like little white larva with brownish heads. They move away pretty fast, so look as you dig. It can help to dump the dirt you remove on a black plastic bag and mash the dirt around to check it. Be especially alert if you find roly polys where you dig. Note: if you've had the perimeter treated, don't follow this advice unless you plan to re-treat the areas you disturb. Now, anyone want to talk about carpenter ants?! Here is a link that might be useful: subterranean termites

The etrade-with-the-baby ones are funny in a surreal sort of way except for the one where the kid pukes. UGH. When did it become so acceptable to show barfing on TV? Every time I turn around someone's tossing their cookies, and in ads too, not just TV shows. The Prius ad is heavily CGI'ed. There's a "how we made it" mini-documentary here. I can just envision the ad agency pitching that anti-gas commercial! :-)