Nothing Is Permanent

[dcarch]

It’s always fun to have your first tomato as early as possible and it’s always nice to get as many ripe tomatoes as possible from your late season varieties. (even you like fried green tomatoes)

Until someone can come up with frost tolerant varieties, you have but two options: get a greenhouse or move to warmer climates.

For various reasons, it’s not possible for many of you to install a greenhouse; therefore most of you don’t even bother going to the “Undercover Gardening” forum to see what’s going on there.

I am posting here just to let you know that I have come up with a way to deal with my needs. Go there and check out my thread (Removable Lean-to Greenhouse )and let me know what you think.

My needs (NY, Z6/7):

• I would like to Gain a month before and a month after the first/last frost of growing time.
• A setup which is not too bad looking because I have neighbors.
• A setup which will allow me to plant seedlings directly in ground.
• A setup which will allow me to remove or install the entire GH in about 15 minutes.
• A setup which will not cost too much $.
• A setup which will not be too difficult to build.

dcarch

[dice]

You could grow some in a white- or reflective-lined
16'x16', 10' deep hole in the ground with a plastic
or lexan cover. (10 feet down, ground temperature
is a steady 53F in temperate latitudes. I would probably
use Siberian cultivars at those temperatures, anyway.)

Walls need to be shored up well so that you don't
get a cave-in while you are down there harvesting,
but you can probably make wall supports do double
duty as trellises.

The neighbors will think it's a cold-frame or something,
unless they actually walk up and look into it.

[dcarch]

Originally Posted by dice

You could grow some in a white- or reflective-lined
16'x16', 10' deep hole in the ground with a plastic or lexan cover. ---------.

I will need a few lbs of TNT to blow a hole that big .

dcarch

[dice]

dcarch:

"I will need a few lbs of TNT to blow a hole that big."

See, you do need a backhoe.

A couple of tweaks for anyone contemplating
this seriously:

Dig the hole in land with a slight grade, and use a rigid
top cover. This allows digging a rain trench around it
on top, and most rain will run off the rigid top cover
into the part of the trench on the downhill side, while
still keeping construction of the top to a single plane.
(Rather like rain running off the top of a lean-to.)

One can bury 50-gal plastic drums at the downhill
corners with spigots opening inside for recycled
rainwater access. To water when it hasn't been
raining, refill the barrels from the top.

A second line defense against having it become a
swimming pool in a deluge is digging another
hole a little deeper around 20' away, dropping
in a couple feet of gravel, and burrowing a hole
from the greenhouse pit to that other hole
with a 6" or 8" air-powered hog, at a slight
downward angle. (A "hog" is a torpedo-shaped
tool used for digging underground conduit holes,
etc. Runs on compressed air.) Then put drain pipe
in the hole made by the hog, with a screen on the
uphill end at the greenhouse pit. (This second hole
can be filled in afterwards.)

One would need some sort of trapdoor in the top
to get in and out, of course, unless one builds
a downward slanting entrance to a regular door
in the side (which might make it more convenient
to get a tiller in and out; something to consider
when designing the wall supports, too, how to
make sure that you can still conveniently amend
the soil.)

I saw a picture of this kind of underground
greenhouse once a long time ago. It was nothing
like this elaborate, just a 10'x10'x10' hole with
regular 6-mil plastic on top that had ripe tomatoes
on green indeterminate plants around the walls
while there was snow on the ground around the
top of the hole. I don't know how the person that
grew those tomatoes kept it from becoming a big
hole full of water in a heavy rain.

I suppose this does not really qualify as "portable",
but it does have low visual impact on the
neighborhood if that's what someone really wants
that has the resources to build it.

[dcarch]

Greenhouse removed yesterday.

Everything went according to plan.

Going to have tomatoes much earlier than last year!

http://www.tomatoville.com/showthread.php?t=4486&page=5

check out the video.

dcarch

[harleysilo]

I never thought about digging a giant hole in the ground for a greenhouse, would be great for my favorite plants....

I like your green house solution. I was just telling my wife yesterday I might want to make our garden into a greenhouse but I don't need one all year, just form October/November till April.....And I like the idea of quickly setting it up and taking it down like you have done.

Do you know how important it is when choosing the panels to consider the design regarding letting light through? I think I would consider using the corrugated clear plastic pieces people use for roofs over patios, but not sure if enought light would be let in....

[dcarch]

Originally Posted by harleysilo

I like your green house solution. I was just telling my wife yesterday I might want to make our garden into a greenhouse but I don't need one all year, just form October/November till April.....And I like the idea of quickly setting it up and taking it down like you have done.
Do you know how important it is when choosing the panels to consider the design regarding letting light through? I think I would consider using the corrugated clear plastic pieces people use for roofs over patios, but not sure if enought light would be let in....

I highly recommend using Twinwall type of polycarbonate panels because of their rigidity and insulating qualities. What makes my design work to survive several major windstorms is the use of packing tape to tie the rigidity together; the whole structure behaves like an airplane fuselage, or like a tube. I use 4mm thick panels. If you are in a colder area or windier area, you may have to use thicker panels.

The insulating walls will minimize the need for heating.

The design requires very little other structural elements, therefore it is very transparent.

dcarch

[dice]

Anyone tried Lexan for one of these?

I don't know about its light-transmitting
properties with a UV resistance coating,
and Lexan is not inexpensive, but it is
very tough material (you can't throw a rock
through it, for example). Lexan is not limited
to 4'x8's or similar sizes, it can be bought in
long rolls 4' or 6' wide (probably other sizes,
too, but those widths are a standard product
in the US, not special order from a factory).

[dcarch]

Originally Posted by dice

Anyone tried Lexan for one of these?
I don't know about its light-transmitting properties with a UV resistance coating, and Lexan is not inexpensive, but it is very tough material (you can't throw a rock through it, for example). Lexan is not limited to 4'x8's or similar sizes, it can be bought in long rolls 4' or 6' wide (probably other sizes, too, but those widths are a standard product in the US, not special order from a factory).

Bullet-proof panels are made with Lexan, which is polycarbonate.

Other special properties which cannot be done with glass:

1. you can cut, drill, screw poly.
2. poly panels can be cut into any shape.
3. Poly panels can be cut with a hole in the middle.
4. You can heat bend/curve poly panel.
5. You can glue poly panel.

special considerations:

1. Poly panels expand/contract much more than glass with temperature changes.
2. Poly panel will curve when one side is more moist than the other.
3. Less abrasion resistant than glass.
4. fire.

dcarch