Greenhouse on the cheap.

I have always wanted a greenhouse, probably because I was allowed to play in a very cool greenhouse my mom's friend had when I was young., Of course that was in western Washington where it was beneficial.  For my birthday 2019 I found a basic one half price at Sam's club. My daughter got it for me.  I put it together in January 2020. I started seeds in my new greenhouse.  It was definitely a learning experience.  Things started off well, but went down hill in a hurry.  I live in Northern California, and we had a little heat wave ( in February believe it or not) and fried a lot of my little seedlings.  I got tons of bugs.  It wasn't a total fail, I got lots Of veggie to plant and give away, and I learned a lot.  
The main thing I loved about my little greenhouse is just having space to start a bunch of seeds where my cats can't eat them, and the chickens won't dig them up.  The greenhouse is a 4'X4' aluminum frame covered in clear plastic.  The plastic had a few rips I planned to use a strong tape to fix.  Yesterday we had a very strong wind storm.  More windy than I remember. Lost power for 13 hours.  Lots of property damage.  We were lucky, lost 2 metal roof panels on the barn, but that's easy enough to fix.  My greenhouse on the other hand didn't survive.  It's now a naked frame.  I used large chunks of concrete we had hanging around, to anchor it down, thank goodness, I'm sure it is why the frame didn't blow away.  I would like to fix it, but don't want to spend a lot of money.  Partly because I'm still learning, second I  can only use it a couple months out of the year, because we have wonderful weather, and I don't really need it.  Does the plastic I use have to be clear?  I have some strong inexpensive plastic,  it's clear but it is cloudy.  I want my little seedlings to be able to absorb the light they need.  I would just cover the hole thing using duct tape to hold it tight.  I could use the cloudy stuff on the bottom, and buy the clear plastic for the roof.
I have a bunch of that wavy metal roof panels.  What if I put it around the bottom. Then buy the plastic version of it for the rest of the sides, and roof.  The plastic panels are 8'X2' for 17.00$. So about 34.$ if I can make two work.  Does anyone know if I can cut those wavy plastic panels?  I thought I could use screws to attach the panels metal and plastic to the frame.  Then maybe use silicone to seal all the seams.  I also intend to make a frame for screen and a cover for that so I will have ventilation while keeping some of the bugs out. (I will do this no matter the material I choose because I think lack of ventilation was a major flaw in the original design.) There would be one on each end.  
I would love to hear what your thoughts are.  I would just like my little greenhouse not to cost much, and it would be nice if lasted more than a year.  If I get the hang of it some day I would love to build a greenhouse out of old windows, and glass doors, ect. to be a permanent greenhouse/ garden work space.  That dream is for the future.  Anyway thanks, happy gardening.

Those aluminum frame kits are not meant for our winds!

For seedlings any plastic that lets light through works. Have you looked online for uv rated sheets? You may be able to find some better quality stuff for around the same price. We bought a 24x32 sheet for about $75. I'm thinking you could use half of that for what you need.

When we cut fiberglass panels many years ago I believe it was a plywood blade mounted backwards so it's more heat that edge cutting.

Hit submit instead of attach...

A bomb cyclone last winter picked this up and tossed it about fifty feet into our fence. We had even mounte 4x4 pressure treated wood all around the bottom to give it a chance in our winter storms. Wasn't enough!

This greenhouse could probably be constructed for under $300 (definitely can if lumber prices ever go back down). It was far cheaper for us because we used things we had on hand. The cattle panels, lumber and fasters were already here. We had to purchase the plastic, uv rated and supposedly will last five years. The design could be simplified, we mounted on posts so we could lift the side flaps for passive air flow. It could even be cut in half.

The round design seems to hold up to the wind much better. We were watching it over the past couple days and didn't see any significant movement or effect.

Came back to add that I'm not sure why I thought we needed a "floor". Mostly to keep from having to weedeat. We now plan to pull the plastic and deep mulch with wood chips. That way I can use the ground in there!

Thanks Melonie, I like your greenhouse a lot.  It seems strong, but design I could probably manage. A great design for the future.  For this year I would like to repurpose what I have, since now is when I need it.  I will definitely look into the uv plastic. Thanks for the tip.  I would love to see what you grow in your greenhouse, and how it works for you.  Thanks 😊

Ooh damn, that looks very familiar Melonie... A few months back, while WWOOFing, I helped dismantle a capsized aluminium-frame greenhouse. In that case, though, the culprit was an insanely heavy November snowfall. The host's neighbour lost his bet though (he thought the wind would take it first...)

It's done.  Time will tell if it will last more then one season.  I enjoyed making it.  Took me longer then I expected, cost a bit more then I wanted and I made tons of mistakes, some I fixed, and some I decided to live with.  All and all I enjoyed the process and learned a lot.  Mostly I was struggling with how to attach the plastic. Originally I thought duck tape, but I decided the sun would melt the glue on the tape and I would just have a mess on my hands this summer. My son came up with the idea to put a wood frame around the perimeter of the greenhouse frame, and attach the plastic to the wood.  I'm a little addicted to the clearance wood at Home Depot,  so I had an assortment of wood I got at some point cheap.  My primary objective when it came to building the door and door frame was to keep it light. (the original greenhouse frame is made from aluminum and plastic after all) The door was a challenge for me.  I am not a builder which you can clearly see.  Needed to be light, and strong enough to open and close a million time, and I wanted to have a screened in window of sorts that could be closed or open depending on the weather.  I am happy with the way it turned out. The wood on the back of the greenhouse is there to secure the plastic at the end, also to create a little screened in window.  that windows plastic is scoured on top with the frame and there is a piece of wood at the bottom to hold the shape and give a bit of weight.  I put Velcro on the sides and bottom (had to put a couple of nails in to keep it in place) Again lightweight, and I can open a little, or a lot. I used one piece of plastic draped from one side of the greenhouse to the other side, and the ends secured with the door frame, and back wood.  When I finally finished I laid some cement bricks in front of the door to make it easy to open.  I pulled the weed and some of the woodchips away from the perimeter laid down cardboard and dumped woodchips on.  Then I decided I worked so hard I wanted it to look nice, so I added a few fun items.  The only thing I bought for this greenhouse was the plastic for 26.00 (the plastic I had was only 3ml, and I read I needed at least 6ml.) The Velcro, which was 6.oo but I have a lot left. And the big white flower on the front, which I got for 7.00.  More then I would normally pay for something like that, but it was just what I wanted (I needed something to cover the terrible job I did at attaching the X in the window)  everything else I already had, or made with what I had.  Oh I forgot the solar light.  They cost me ten for the pair.  Total splurge, but just the touch I was looking for.  I know it wont last long with the California sun, but I have lots of plastic left over, so  redoing it will not cost anything and can be done pretty fast.  I hope as time goes by I will accumulate enough windows and glass and knowledge to build a real greenhouse.  Until that time comes I will enjoy this one.  My daughter who bought me the greenhouse was super happy I fixed it and didn't just throw it away, so that's icing on the cake. (silly girl, knows even when it's done being a greenhouse it will end up repurposed for something else.)  Now I can reclaim my dining room table and give my seedlings a new home.  Thanks all happy gardening.

Just out of curiosity, Jen, do you plant enough seedlings that a garden window would be out of the question as a new installation on the south side of your house?  Depending on the timing of planting in the spring, you may be able to get a number of crops started as seedlings in such a window sill.....AND not have to worry about winds, overheating, and the surprise cold snap!  Maybe of some use?.....

I would love a garden window. Maybe when we redo the kitchen in the future.  Thanks

Just adding to this thread as I went in search for a garden window this spring for a south-facing window in our home.  Perhaps due to the impact of the pandemic on the general economy but I was coming up quite short in affordable offerings of these as pre-fab windows for purchase.  Building one didn't seem a major investment so cobbled together older lumber around the property and will finish the roofing with metal scraps from a recent garage project that also will match the roof color of the house.  The windows were purchased new.....perhaps should have gone with a standard double-hung for the  direct south facing window, but opted for the more economical storm window instead.  The 14 inch wide side windows are "basement sliders".....because I could not find double- or single-hungs in something narrower than 18 inches....total window cost ~$160.00.  It still needs some work mid-summer, but for now will be housing some tomato and pepper seedlings that need a jump start before planting in late May/early June.  The early framing photo on top is followed by an interior view and then the nearly finished exterior view.

John that is so cool.  Way better than the garden window.  Did you install it in a window or a door space?  Thanks for sharing this, I actually have an old door space in our family room that used to be a garage so there are 2 doors the one we never use is on the south side.  You have my imagination going wild thanks.

Jen Fulkerson wrote:It's done. ...

Wow, Jen, not only have you created a wonderfully functional greenhouse, but a beautiful work of art, too! I bet it looks very sweet in your garden! I feel inspired - thanks for sharing!

Jen, How has your greenhouse been holding up now so far?  I can't recall what kinds of winds you have had this spring season in N. Cal. but I hope it's been calm and the greenhouse holding fast so far.  Nice structure!  To answer your question, the new garden window is actually perched on the roof of a 3-season sun-room.  We could put plants in the sun-room itself, but there is too much of a risk of the dogs knocking something over since that is their main sitting room and entry-way that they use to get into the house.  The house window that is covered by the new construction is actually a stair-way window.....positioned half-way in height between the windows on the main floor and the second story of the house.  And yes.....if I had a ground-level exiting doorway on the south side of house, I would jump at the opportunity to build a larger-sized version of this to serve as a mini mud-room/greenhouse/potting-shed/New-Renaissance-man-cave... :-)  If my wife's step-father up near Willits wouldn't have built that yurt back in the 70's, I'd be pushing him to add one as well!...But he's now dedicated to "corner-free living" and I'm all tinker-toys and 2X4s.  Ha!

The greenhouse is holding up great. Yes we have been having lots of strong winds this spring.  Worse the last couple of years then I remember. Maybe climate change? I don't know. I think I noticed more because they took out the mature walnut orchard on our north and west sides.  They planted a almond orchard on the north side so maybe it will get better once the trees are bigger. My little greenhouse didn't budge. I do have large chunks of cement in the corners on top of the frame to hold it down.  So far the plastic is holding.
My only problem isn't a new one.  It gets to 🥵 hot.  The other day it was 115 inside.  I knew this, and that is why I put in the windows.  They are open 24/7 at this point, and does help. I'm looking into a solar fan.  So far they are to expensive.  If it was a real greenhouse I might be willing to bare the cost.  I could buy a cheap electric fan, and put it on a timer.  It's hard to justify stuff like this because I'm lucky to live in a place with an incredibly long growing season, so a greenhouse is mostly an indulgence.  
I enjoy it, so it was worth the time it took to fix, and I learned a lot.

Jen Fulkerson wrote: I'm looking into a solar fan.  So far they are to expensive.  

I found a solar attic fan for about $55. Still kind of steep if we're watching pennies though.
https://www.homedepot.com/p/Active-Ventilation-365-CFM-Brown-Powder-Coated-5-Watt-Solar-Powered-Roof-Mounted-Exhaust-Attic-Fan-RBSF-8-BR/204202995?source=shoppingads&locale=en-US&mtc=Shopping-B-F_D22-G-D22-22_51_ROOFING-NA-NA-Feed-SMART-NA-NA-New_Engen&cm_mmc=Shopping-B-F_D22-G-D22-22_51_ROOFING-NA-NA-Feed-SMART-NA-NA-New_Engen-71700000076048518-58700006492368435-92700060737533157&gclid=Cj0KCQjw38-DBhDpARIsADJ3kjkJsTOwJPuLRF7ZK60puuMeOp4Lis00Lo8yAbbeVJuTNzCuLd2GF6QaAnr8EALw_wcB&gclsrc=aw.ds

Thank you so much, that was very nice of you.  I think I will keep looking. It's more than I want to spend, and I probably need a fan that is attached to the solar panel by a cord. The frame is just aluminum, not that strong, and my greenhouse is a little less than 5' X5' so that might be to big, and heavy.  I will probably look at them the next time I'm at Home Depot, you never know. Thank you.

If you're not opposed to salvaging, you can get old computer fans for free all over the place.  You could make a 4x4 grid of them and attach a small solar panel and be all set.  They already run on 12 volts, so no converting necessary.

Thanks Trace.  We have several old computers in our garage. My son loves to  build stuff like that. I think I will ask him.  Although it means seeing the I told you so face my husband will give me because I have been bugging him for years to get rid of that crap.  Encourage the border, or not get my fan, 🤔 that's a hard one.   Thanks again.

Jen Fulkerson wrote:John that is so cool.  Way better than the garden window.  Did you install it in a window or a door space?  Thanks for sharing this, I actually have an old door space in our family room that used to be a garage so there are 2 doors the one we never use is on the south side.  You have my imagination going wild thanks.

I know my setup is for colder climate but
since you mentioned you have a south door that doesn't need to get used.
I built a small 8x4 porch on the south side of my house a few years back.
Probably should have built it big enough for a rocking chair,  ha.
It's the main entry in the summer.
But when winter comes
I wrap it in plastic and bubblewrap:

The first year I just wrapped it in plastic but frost built up on real cold days.
 Found some real nice/large sheets of bubble wrap in the furniture store dumpster.
So I used them the next year.
As you can see it requires a small window a few inches up from the bottom.

It opens into the house:
solarroominside by vwfatmobile, on Flickr
And is used to heat the house/kitchen in the winter.

I used a 12 volt 4" computer fan in the top right corner of the doorway.
Run by a solar panel.

I noticed a few days ago the plastic on top that touches the frame has already split.  I knew it wouldn't last a long time because the sun is brutal, but to fail in less than a year is a bummer.  The plastic on the sides is fine, not brittle like the top.  I think I will buy a plastic roof tile.  I looked into using them when I was redoing the greenhouse in the first place, but it was just to expensive. I can afford one panel, so I'm thinking I can use the panel as the roof, and use silicone to adhere the panel to the plastic.
Woulda shoulda coulda.  I should have covered it for the summer.
Oh well live and learn.  
If you have a suggestion that isn't very expensive, I'm all ears. Thanks