Mini Greenhouse / Coldframe

extinctearth · Post by **extinctearth** » Wed Jul 21, 2010 12:45 pm

I've been looking into getting some kind of mini greenhouse or cold frame. The last month has been horrible for weather (humid and rainy) and I work third shift so I can't keep the cactus outside without protection. Any thoughts on type / brand? It can get quite windy sometimes and rains heavily every few weeks (at least). I don't plan on keeping it out during the winter.

DWDogwood · Post by **DWDogwood** » Fri Jul 23, 2010 4:51 am

With wind, I'd say keep it low, so a cold frame design would work. Honestly cheap fir kiln dried 2x4 framing covered in a Behr Deck and siding stain and glazed with corrugated UV polycarbonate sheeting will keep the rain off. The weight of the lumber is much preferred over the aluminum framed cold frames you can get at Charley's Greenhouses or the like. You can build a 4x4 box with a lid for 150.

iann · Post by **iann** » Fri Jul 23, 2010 1:18 pm

You can build for a lot less than that. I just built a 4x4 low brick frame that I can put polycarbonate sheeting over. Handy for storing extra Lithops which aren't very tall. I could make it taller obviously

extinctearth · Post by **extinctearth** » Fri Jul 23, 2010 3:32 pm

I want it to be movable so I'm going to go with wood.

I thought wood treated with anything was bad for plants? I was suggested cedar, but that stuff will run a bit of money.

Should I just have a window where the lid is or on all sides?

What should I use for my windows? Glass would be nice for the price, but I haven't been able to find any (plus when I move it it could break). Lexan looks kind of high priced. Thin plastic sheeting gets condensation and mold growth right?

hob · Post by **hob** » Fri Jul 23, 2010 3:53 pm

extinctearth wrote: I thought wood treated with anything was bad for plants?

my shelves are pressure treated ........that seems to be ok

Harriet · Post by **Harriet** » Fri Jul 23, 2010 8:09 pm

extinctearth wrote:I thought wood treated with anything was bad for plants?

I would think that would be true only of you are making planters out of the treated wood. Putting a plant in a pot on a treated wood shelf has never been a problem for me.

iann · Post by **iann** » Fri Jul 23, 2010 8:51 pm

Transparent sides are good but a bit harder to make. It doesn't matter too much if you have plenty of light and the plants won't be too deep down inside a dark box.

Old windows are handy. Failed double glazing units are usually free if you know the right people, and much stronger than a single pane of glass. You'd probably want to put glass in some sort of frame, probably well hinged to the rest of the structure.

Plastic is easier, you can just plonk it down and put a brick on top

Twinwall is a pain if you don't seal the ends of the channels.

extinctearth · Post by **extinctearth** » Sun Jul 25, 2010 5:13 am

Any thoughts on acrylic? It is harder than glass, has uv protection and is quite cheap.

roburtvigr · Post by **roburtvigr** » Thu Jul 29, 2010 9:27 am

Hey nice information. actually I also want to know about the mini greenhouse or cold frame. and I got information about it. I like it and you give information is really helpful to me.

iann · Post by **iann** » Thu Jul 29, 2010 2:36 pm

Acrylic isn't harder than glass, you can scratch it quite easily. That's one of the downsides, it will eventually mark up. It's much more shock-resistant than glass though and you'll never shatter it. Not as tough as polycarbonate, but tough enough for greenhouses. Just make sure the sheets you get are rigid enough for what you want to cover. Are you looking at twinwall sheeting?

Tony · Post by **Tony** » Thu Jul 29, 2010 2:58 pm

I have been using the acrylic sheet roofing that the Home depo sells now for 6+ years. Its strong inexpensive and has held up really well.
I use it to cover tables and to enclose my green house which cost less than 100 bucks (and it looks it

)to build about six years ago.
If you experience large hail however, you might want to use the polycarbonate pannels, it is practicly indestructible.

Post by **daiv** » Thu Jul 29, 2010 5:06 pm

When I think Acrylic, I think "Plexiglas". Tony, do they make corrugated acrylic for roofing?

I find Plexiglas to be rather expensive at least about as much as Polycarbonate.

Tony · Post by **Tony** » Thu Jul 29, 2010 6:55 pm

Tony, do they make corrugated acrylic for roofing?

Yes, they do. I will try and get an image of it by itself later if you want, I just used the above image because it was the best I could find early this morning that had the greenhouse in it.

Buck Hemenway · Post by **Buck Hemenway** » Thu Jul 29, 2010 8:20 pm

Home Depot used to carry three grades ending in polycarbonate. What Tony is talking about is their middle grade. I used the cheap stuff on one structure and got 4 years out of it. Polycarbonate has been up and is in good shape for 14 years.

Peterthecactusguy · Post by **Peterthecactusguy** » Thu Jul 29, 2010 10:08 pm

haha when I worked at home depot they had three colors of those things. I am not sure what grades they were, however the clear one was the better grade I think cause some people there said it was great and lasted them for about 10 years in the desert and they bought them. They looked like corrugated metal but were plastic, polycarbonate I believe.