I'm thinking about getting a greenhouse this year to extend my season (I
live in Massachusetts). Last fall someone on this group suggested I try a
popup greenhouse because they are very cheap (under $150, some as low as
$50), rather then make any kind of major investment. Does any one have
any experience with them? There also seems to be a class of greenhouses
that are a step up, around $600-$700. The cheap ones are basically
plastic tents, the mid priced ones are aluminum and polycarbonate. I'd
like your opinions on both types. In my heart of hearts I've always
wanted a proper glass Victorian greenhouse, but that's real money so I
want to see if a greenhouse is helpful to me before I make that kind of
investment.

"General Schvantzkoph" wrote in message
...
I'm thinking about getting a greenhouse this year to extend my season (I
live in Massachusetts). Last fall someone on this group suggested I try a
popup greenhouse because they are very cheap (under $150, some as low as
$50), rather then make any kind of major investment. Does any one have
any experience with them?


I bought a $110 plastic greenhouse from Walmart. It was easy to assemble.
The workmanship was a little shoddy, but nothing drastic--just a zipper
off-kilter, some crooked seams, that sort of thing.

There were two problems I saw, and these might not be problems for you:

1. It didn't stay warm at night. I'd see seedlings popping up during the
day (when it was VERY hot inside the greenhouse), then they'd die overnight.
If you are going to put some nighttime heating in it, then this probably
wouldn't be an issue for you.

2. The wind completely took it away. We staked it down all around AND put
concrete cinderblocks around the perimeter of the greenhouse, but on one
windy night the entire thing was pulled up from its stakes and blown into a
tree, where it twisted and broke. The plastic was ripped, and the metal
bars were bent and sheared clean off at some places. (A few of the stakes
were still in the ground; the wind had separated the poles at the joints and
lifted them away!) If you do not have a lot of wind where you live, this
shouldn't be a problem.

I really like the idea of these inexpensive greenhouses, but for me it was a
waste of money.
--S.

On Sun, 07 Mar 2010 12:36:25 -0700, Suzanne D. wrote:

"General Schvantzkoph" wrote in message
...
I'm thinking about getting a greenhouse this year to extend my season
(I live in Massachusetts). Last fall someone on this group suggested I
try a popup greenhouse because they are very cheap (under $150, some as
low as $50), rather then make any kind of major investment. Does any
one have any experience with them?


I bought a $110 plastic greenhouse from Walmart. It was easy to
assemble. The workmanship was a little shoddy, but nothing drastic--just
a zipper off-kilter, some crooked seams, that sort of thing.

There were two problems I saw, and these might not be problems for you:

1. It didn't stay warm at night. I'd see seedlings popping up during
the day (when it was VERY hot inside the greenhouse), then they'd die
overnight. If you are going to put some nighttime heating in it, then
this probably wouldn't be an issue for you.

2. The wind completely took it away. We staked it down all around AND
put concrete cinderblocks around the perimeter of the greenhouse, but on
one windy night the entire thing was pulled up from its stakes and blown
into a tree, where it twisted and broke. The plastic was ripped, and
the metal bars were bent and sheared clean off at some places. (A few
of the stakes were still in the ground; the wind had separated the poles
at the joints and lifted them away!) If you do not have a lot of wind
where you live, this shouldn't be a problem.

I really like the idea of these inexpensive greenhouses, but for me it
was a waste of money.
--S.

Thanks for your feedback. Both of those things are issues, I wondered how
something that was basically a tent could stand up to any kind of wind,
apparently they can't.

In article ,
General Schvantzkoph wrote:

On Sun, 07 Mar 2010 12:36:25 -0700, Suzanne D. wrote:

"General Schvantzkoph" wrote in message
...
I'm thinking about getting a greenhouse this year to extend my season
(I live in Massachusetts). Last fall someone on this group suggested I
try a popup greenhouse because they are very cheap (under $150, some as
low as $50), rather then make any kind of major investment. Does any
one have any experience with them?


I bought a $110 plastic greenhouse from Walmart. It was easy to
assemble. The workmanship was a little shoddy, but nothing drastic--just
a zipper off-kilter, some crooked seams, that sort of thing.

There were two problems I saw, and these might not be problems for you:

1. It didn't stay warm at night. I'd see seedlings popping up during
the day (when it was VERY hot inside the greenhouse), then they'd die
overnight. If you are going to put some nighttime heating in it, then
this probably wouldn't be an issue for you.

2. The wind completely took it away. We staked it down all around AND
put concrete cinderblocks around the perimeter of the greenhouse, but on
one windy night the entire thing was pulled up from its stakes and blown
into a tree, where it twisted and broke. The plastic was ripped, and
the metal bars were bent and sheared clean off at some places. (A few
of the stakes were still in the ground; the wind had separated the poles
at the joints and lifted them away!) If you do not have a lot of wind
where you live, this shouldn't be a problem.

I really like the idea of these inexpensive greenhouses, but for me it
was a waste of money.
--S.

Thanks for your feedback. Both of those things are issues, I wondered how
something that was basically a tent could stand up to any kind of wind,
apparently they can't.

Maybe nestled up to a south facing wall with east and west protected
with a few cider blocks. As I understand it auto venting device is
really of import or the heat which varies a lot due to no solar mass
fries or freezes your plants. I's add gallons of water maybe half your
space to try to moderate the temperature swings. Small maybe beautiful
but one has to work harder on your design.

--
Bill Garden in shade zone 5 S Jersey USA
http://www.globalissues.org/article/75/world-military-spending

On 7 Mar 2010 18:58:13 GMT, General Schvantzkoph
wrote:

I'm thinking about getting a greenhouse this year to extend my season (I
live in Massachusetts). Last fall someone on this group suggested I try a
popup greenhouse because they are very cheap (under $150, some as low as
$50), rather then make any kind of major investment. Does any one have
any experience with them? There also seems to be a class of greenhouses
that are a step up, around $600-$700. The cheap ones are basically
plastic tents, the mid priced ones are aluminum and polycarbonate. I'd
like your opinions on both types. In my heart of hearts I've always
wanted a proper glass Victorian greenhouse, but that's real money so I
want to see if a greenhouse is helpful to me before I make that kind of
investment.

I bought a 12.5' x 8' greenhouse from Costco about 5 years ago. I
love it, but even here in NC you can't do much to extend the season
with heat at night. http://tinyurl.com/yfkudkx It was somewhat
cheaper when I bought it. It was on sale and we were up at midnight
to get online and order it. The price includes shipping.

The interior gets down to whatever the outside temps are at night. As
soon as the sun comes up it starts getting hot. With the door closed
and a nice bright day it will be 105° inside. We ran water and
electric when we poured the slab. This one comes with lights, fans,
shelves and other stuff. I have discovered that it is cheaper to
germinate seeds in the house and then move them out to greenhouse than
to try to keep the GH warm enough at night for germination.

As I mentioned in another thread, I am getting a late start this year.
Besides we had snow the beginning of this week. Tomorrow it is
supposed 61°.

Think carefully and specifically what you hope to accomplish with a
greenhouse and how much you would like to have in it. About April one
of my 8' shelves is packed with trays in various stages before setting
out. If I got very ambitious I could clear the shelf on the other
side. The cost of heat can be a real bear. I did not heat the
greenhouse this winter and it was so cold that our electric bill was
double what it was last year. I will be putting some trays out there
in a few more days so I will have room to start some more things.

Ask more questions as you think more about what you want.

--
USA
North Carolina Foothills
USDA Zone 7a

On Sun, 07 Mar 2010 14:51:41 -0500, The Cook wrote:

tinyurl

That one is starting to be real money, the problem with even thinking
about spending several thousand is that the next step is to start
thinking about spending 5 to 10 times that much and getting a really
nice one. This year I want to keep it down to a few hundred dollars,
maybe as much as $650, something like this

http://www.amazon.com/Rion-Greenline...987863&sr=8-10

One of the other reasons that I'm thinking about this is to protect some
tomato plants from blight. Last year I nearly lost everything to early
blight. I read somewhere that protecting plants from wind and rain reduces
the transmission of blight, can someone comment on this?

General Schvantzkoph wrote:
I'm thinking about getting a greenhouse this year to extend my season
(I live in Massachusetts). Last fall someone on this group suggested
I try a popup greenhouse because they are very cheap (under $150,
some as low as $50), rather then make any kind of major investment.
Does any one have any experience with them? There also seems to be a
class of greenhouses that are a step up, around $600-$700. The cheap
ones are basically plastic tents, the mid priced ones are aluminum
and polycarbonate. I'd like your opinions on both types. In my heart
of hearts I've always wanted a proper glass Victorian greenhouse, but
that's real money so I want to see if a greenhouse is helpful to me
before I make that kind of investment.

My experience is limited to a small cheap portable one that would probably
be called a cold frame more than a greenhouse but it has all the problems
that you will face with a bigger version.

- Too hot when the sun shines on it and high humidity encourages fungi, I
have to open up flaps to allow it to cool on warm days.

- Blows away in strong wind, I move it to shelter and/or tie it down.

- Loses heat quickly at night, I move it under shelter.

- Limited lifetime, even "UV stabilised" plastic will only last a few
years.

David

On Mar 7, 1:58*pm, General Schvantzkoph
wrote:
I'm thinking about getting a greenhouse this year to extend my season (I
live in Massachusetts). Last fall someone on this group suggested I try a
popup greenhouse because they are very cheap (under $150, some as low as
$50), rather then make any kind of major investment. Does any one have
any experience with them? There also seems to be a class of greenhouses
that are a step up, around $600-$700. The cheap ones are basically
plastic tents, the mid priced ones are aluminum and polycarbonate. I'd
like your opinions on both types. In my heart of hearts I've always
wanted a proper glass Victorian greenhouse, but that's real money so I
want to see if a greenhouse is helpful to me before I make that kind of
investment.

We're in Maryland, a bit north of Baltimore. We bought a $700, 10' x
12' greenhouse kit from Harbor Freight a few years ago and put it up
on the south side of the house. It heated well with a 220 volt heater
but wouldn't stand up to the wind. The first windstorm sent about a
third of the panels all over the property. I tried to add extra clips
and adhesive but the next windstorm still took off a few panels. The
structure was too flexible, allowing the doors to open and the wind to
get in. I tried adding cross-members inside to strenghten it but it
was pretty much gone by that point.

The next year, I built a wood-framed greenhouse against the south side
of the house. I recycled most of the panels and windows from the
original greenhouse for the walls of the new one and put heavy-duty
double-wall polycarbonate panels on the roof. Everything held against
the winds for two years and against over four feet of snow on the roof
this winter.

Paul

On 7 Mar 2010 20:13:03 GMT, General Schvantzkoph
wrote:

On Sun, 07 Mar 2010 14:51:41 -0500, The Cook wrote:

tinyurl

That one is starting to be real money, the problem with even thinking
about spending several thousand is that the next step is to start
thinking about spending 5 to 10 times that much and getting a really
nice one. This year I want to keep it down to a few hundred dollars,
maybe as much as $650, something like this

http://www.amazon.com/Rion-Greenline...987863&sr=8-10

One of the other reasons that I'm thinking about this is to protect some
tomato plants from blight. Last year I nearly lost everything to early
blight. I read somewhere that protecting plants from wind and rain reduces
the transmission of blight, can someone comment on this?

I am not sure that a greenhouse is going to keep late blight away. The
spores travel through the air and you cannot keep a greenhouse closed
during the summer. Today I checked the temperature in the greenhouse
and it was 134°. The outdoor temperature is about 60°. Check this
site on late blight.
http://plantclinic.cornell.edu/FactS...light/late.htm
--
USA
North Carolina Foothills
USDA Zone 7a

Bill who putters wrote:
In article ,
General Schvantzkoph wrote:

On Sun, 07 Mar 2010 12:36:25 -0700, Suzanne D. wrote:

"General Schvantzkoph" wrote in message
...
I'm thinking about getting a greenhouse this year to extend my season
(I live in Massachusetts). Last fall someone on this group suggested I
try a popup greenhouse because they are very cheap (under $150, some as
low as $50), rather then make any kind of major investment. Does any
one have any experience with them?

I bought a $110 plastic greenhouse from Walmart. It was easy to
assemble. The workmanship was a little shoddy, but nothing drastic--just
a zipper off-kilter, some crooked seams, that sort of thing.

There were two problems I saw, and these might not be problems for you:

1. It didn't stay warm at night. I'd see seedlings popping up during
the day (when it was VERY hot inside the greenhouse), then they'd die
overnight. If you are going to put some nighttime heating in it, then
this probably wouldn't be an issue for you.

2. The wind completely took it away. We staked it down all around AND
put concrete cinderblocks around the perimeter of the greenhouse, but on
one windy night the entire thing was pulled up from its stakes and blown
into a tree, where it twisted and broke. The plastic was ripped, and
the metal bars were bent and sheared clean off at some places. (A few
of the stakes were still in the ground; the wind had separated the poles
at the joints and lifted them away!) If you do not have a lot of wind
where you live, this shouldn't be a problem.

I really like the idea of these inexpensive greenhouses, but for me it
was a waste of money.
--S.
Thanks for your feedback. Both of those things are issues, I wondered how
something that was basically a tent could stand up to any kind of wind,
apparently they can't.

Maybe nestled up to a south facing wall with east and west protected
with a few cider blocks.


I like that idea.

You may wish to look at home made hoop greenhouses. Easiest way is to
drive rebar into the ground, and pop the hoops on the exposed rebar. You
will need to recover every few years, but the material is cheap.

One example:

http://westsidegardener.com/howto/hoophouse.html

My general advice, curves are strong and resist wind. If you can prop
this against a south facing wall you will cut your heating needs.
Greenhouses lose heat at night, and lots of it. Without added heat,
inside temperature will be the outside temp by morning if not long before.


As I understand it auto venting device is
really of import or the heat which varies a lot due to no solar mass
fries or freezes your plants. I's add gallons of water maybe half your
space to try to moderate the temperature swings.


Water is one BTU per pound water degree F. Heat loss for single layer is
~ 1 BTU/hr per square foot times the temperature difference. It adds up
to a lot of water as Bill has said. Try Drums. Other materials store
heat, but not as well as water.

Double or triple wall polycarbonate will cut the heat loss by almost a
half to two thirds.

I'll retrofit my solar cabana with mylar storms this fall. Clear
mylar degrades in UV so it needs a UV outer barrier.

I've been using vinyl shower curtain liners. They are very clear and
hold up well, so far.

Jeff

Small maybe beautiful
but one has to work harder on your design.

In article ,
Jeff Thies wrote:

Bill who putters wrote:
In article ,
General Schvantzkoph wrote:

On Sun, 07 Mar 2010 12:36:25 -0700, Suzanne D. wrote:

"General Schvantzkoph" wrote in message
...
I'm thinking about getting a greenhouse this year to extend my season
(I live in Massachusetts). Last fall someone on this group suggested I
try a popup greenhouse because they are very cheap (under $150, some as
low as $50), rather then make any kind of major investment. Does any
one have any experience with them?

I bought a $110 plastic greenhouse from Walmart. It was easy to
assemble. The workmanship was a little shoddy, but nothing drastic--just
a zipper off-kilter, some crooked seams, that sort of thing.

There were two problems I saw, and these might not be problems for you:

1. It didn't stay warm at night. I'd see seedlings popping up during
the day (when it was VERY hot inside the greenhouse), then they'd die
overnight. If you are going to put some nighttime heating in it, then
this probably wouldn't be an issue for you.

2. The wind completely took it away. We staked it down all around AND
put concrete cinderblocks around the perimeter of the greenhouse, but on
one windy night the entire thing was pulled up from its stakes and blown
into a tree, where it twisted and broke. The plastic was ripped, and
the metal bars were bent and sheared clean off at some places. (A few
of the stakes were still in the ground; the wind had separated the poles
at the joints and lifted them away!) If you do not have a lot of wind
where you live, this shouldn't be a problem.

I really like the idea of these inexpensive greenhouses, but for me it
was a waste of money.
--S.
Thanks for your feedback. Both of those things are issues, I wondered how
something that was basically a tent could stand up to any kind of wind,
apparently they can't.

Maybe nestled up to a south facing wall with east and west protected
with a few cider blocks.


I like that idea.

You may wish to look at home made hoop greenhouses. Easiest way is to
drive rebar into the ground, and pop the hoops on the exposed rebar. You
will need to recover every few years, but the material is cheap.

One example:

http://westsidegardener.com/howto/hoophouse.html

My general advice, curves are strong and resist wind. If you can prop
this against a south facing wall you will cut your heating needs.
Greenhouses lose heat at night, and lots of it. Without added heat,
inside temperature will be the outside temp by morning if not long before.

I'd investigate composting manure for heating. Not very esthetic, but
practical.


As I understand it auto venting device is
really of import or the heat which varies a lot due to no solar mass
fries or freezes your plants. I's add gallons of water maybe half your
space to try to moderate the temperature swings.


Water is one BTU per pound water degree F. Heat loss for single layer is
~ 1 BTU/hr per square foot times the temperature difference. It adds up
to a lot of water as Bill has said. Try Drums. Other materials store
heat, but not as well as water.

Double or triple wall polycarbonate will cut the heat loss by almost a
half to two thirds.
and reduce light by 20% - 30%, respectivly. Six mil polyvinyl will
reduce light by 5 - 15%. In low light situations, this could be
important. I was planing on a hoop house, but decided that I couldn't
afford the light loss in my particular situation.

I'll retrofit my solar cabana with mylar storms this fall. Clear
mylar degrades in UV so it needs a UV outer barrier.

I've been using vinyl shower curtain liners. They are very clear and
hold up well, so far.

Jeff

Small maybe beautiful
but one has to work harder on your design.

--
- Billy
"Fascism should more properly be called corporatism because it is the
merger of state and corporate power." - Benito Mussolini.
http://www.youtube.com/watch?v=Arn3lF5XSUg
http://www.thirdworldtraveler.com/Zinn/HZinn_page.html

Billy wrote:
In article ,
Jeff Thies wrote:

Bill who putters wrote:
In article ,
General Schvantzkoph wrote:

On Sun, 07 Mar 2010 12:36:25 -0700, Suzanne D. wrote:

"General Schvantzkoph" wrote in message
...
I'm thinking about getting a greenhouse this year to extend my season
(I live in Massachusetts). Last fall someone on this group suggested I
try a popup greenhouse because they are very cheap (under $150, some as
low as $50), rather then make any kind of major investment. Does any
one have any experience with them?
I bought a $110 plastic greenhouse from Walmart. It was easy to
assemble. The workmanship was a little shoddy, but nothing drastic--just
a zipper off-kilter, some crooked seams, that sort of thing.

There were two problems I saw, and these might not be problems for you:

1. It didn't stay warm at night. I'd see seedlings popping up during
the day (when it was VERY hot inside the greenhouse), then they'd die
overnight. If you are going to put some nighttime heating in it, then
this probably wouldn't be an issue for you.

2. The wind completely took it away. We staked it down all around AND
put concrete cinderblocks around the perimeter of the greenhouse, but on
one windy night the entire thing was pulled up from its stakes and blown
into a tree, where it twisted and broke. The plastic was ripped, and
the metal bars were bent and sheared clean off at some places. (A few
of the stakes were still in the ground; the wind had separated the poles
at the joints and lifted them away!) If you do not have a lot of wind
where you live, this shouldn't be a problem.

I really like the idea of these inexpensive greenhouses, but for me it
was a waste of money.
--S.
Thanks for your feedback. Both of those things are issues, I wondered how
something that was basically a tent could stand up to any kind of wind,
apparently they can't.
Maybe nestled up to a south facing wall with east and west protected
with a few cider blocks.

I like that idea.

You may wish to look at home made hoop greenhouses. Easiest way is to
drive rebar into the ground, and pop the hoops on the exposed rebar. You
will need to recover every few years, but the material is cheap.

One example:

http://westsidegardener.com/howto/hoophouse.html

My general advice, curves are strong and resist wind. If you can prop
this against a south facing wall you will cut your heating needs.
Greenhouses lose heat at night, and lots of it. Without added heat,
inside temperature will be the outside temp by morning if not long before.

I'd investigate composting manure for heating. Not very esthetic, but
practical.


Perhaps perhaps run pex through the remotely located compost pile and
pump the heat into the greenhouse when needed. Lot's of options.

As I understand it auto venting device is
really of import or the heat which varies a lot due to no solar mass
fries or freezes your plants. I's add gallons of water maybe half your
space to try to moderate the temperature swings.

Water is one BTU per pound water degree F. Heat loss for single layer is
~ 1 BTU/hr per square foot times the temperature difference. It adds up
to a lot of water as Bill has said. Try Drums. Other materials store
heat, but not as well as water.

Double or triple wall polycarbonate will cut the heat loss by almost a
half to two thirds.
and reduce light by 20% - 30%, respectivly. Six mil polyvinyl will
reduce light by 5 - 15%. In low light situations, this could be
important. I was planing on a hoop house, but decided that I couldn't
afford the light loss in my particular situation.

It's always a tradeoff. You could have removable insulation and put it
in at night. But that can be a hassle. I've done some removable with
reflective bubble wrap such as this:

http://www.radiantguard.com/reflective-insulation.aspx

I also have this on the north wall and it reflects light in rather
than letting it escapes. It can also be pulled over the top, instead
of inside.

I've got some folding multilayer 1 mil mylar "storms" that has very
low light loss, but it has it's issues.

My benefit here is that while I have very little sun during the
summer, falling leaves changes all that. I may have to become a winter
gardener...

At any rate, there is a lot to consider. And I'm afraid more that the
casual greenhouse user would like to consider!

As you have said, anyone can grow in ideal conditions, it takes a
gardener to grow in what is available!

Jeff

I'll retrofit my solar cabana with mylar storms this fall. Clear
mylar degrades in UV so it needs a UV outer barrier.

I've been using vinyl shower curtain liners. They are very clear and
hold up well, so far.

Jeff

Small maybe beautiful
but one has to work harder on your design.

In article ,
Jeff Thies wrote:

Billy wrote:
In article ,
Jeff Thies wrote:

Bill who putters wrote:
In article ,
General Schvantzkoph wrote:

On Sun, 07 Mar 2010 12:36:25 -0700, Suzanne D. wrote:

"General Schvantzkoph" wrote in message
...
I'm thinking about getting a greenhouse this year to extend my season
(I live in Massachusetts). Last fall someone on this group suggested I
try a popup greenhouse because they are very cheap (under $150, some
as
low as $50), rather then make any kind of major investment. Does any
one have any experience with them?
I bought a $110 plastic greenhouse from Walmart. It was easy to
assemble. The workmanship was a little shoddy, but nothing
drastic--just
a zipper off-kilter, some crooked seams, that sort of thing.

There were two problems I saw, and these might not be problems for you:

1. It didn't stay warm at night. I'd see seedlings popping up during
the day (when it was VERY hot inside the greenhouse), then they'd die
overnight. If you are going to put some nighttime heating in it, then
this probably wouldn't be an issue for you.

2. The wind completely took it away. We staked it down all around AND
put concrete cinderblocks around the perimeter of the greenhouse, but
on
one windy night the entire thing was pulled up from its stakes and
blown
into a tree, where it twisted and broke. The plastic was ripped, and
the metal bars were bent and sheared clean off at some places. (A few
of the stakes were still in the ground; the wind had separated the
poles
at the joints and lifted them away!) If you do not have a lot of wind
where you live, this shouldn't be a problem.

I really like the idea of these inexpensive greenhouses, but for me it
was a waste of money.
--S.
Thanks for your feedback. Both of those things are issues, I wondered
how
something that was basically a tent could stand up to any kind of wind,
apparently they can't.
Maybe nestled up to a south facing wall with east and west protected
with a few cider blocks.

I like that idea.

You may wish to look at home made hoop greenhouses. Easiest way is to
drive rebar into the ground, and pop the hoops on the exposed rebar. You
will need to recover every few years, but the material is cheap.

One example:

http://westsidegardener.com/howto/hoophouse.html

My general advice, curves are strong and resist wind. If you can prop
this against a south facing wall you will cut your heating needs.
Greenhouses lose heat at night, and lots of it. Without added heat,
inside temperature will be the outside temp by morning if not long before.

I'd investigate composting manure for heating. Not very esthetic, but
practical.

Before I started to garden, I found the smell of manure very offensive.
Now when I smell manure, I think of gardening.

Perhaps perhaps run pex through the remotely located compost pile and
pump the heat into the greenhouse when needed. Lot's of options.

As I understand it auto venting device is
really of import or the heat which varies a lot due to no solar mass
fries or freezes your plants. I's add gallons of water maybe half your
space to try to moderate the temperature swings.

Water is one BTU per pound water degree F. Heat loss for single layer is
~ 1 BTU/hr per square foot times the temperature difference. It adds up
to a lot of water as Bill has said. Try Drums. Other materials store
heat, but not as well as water.

Double or triple wall polycarbonate will cut the heat loss by almost a
half to two thirds.
and reduce light by 20% - 30%, respectivly. Six mil polyvinyl will
reduce light by 5 - 15%. In low light situations, this could be
important. I was planing on a hoop house, but decided that I couldn't
afford the light loss in my particular situation.

It's always a tradeoff. You could have removable insulation and put it
in at night. But that can be a hassle. I've done some removable with
reflective bubble wrap such as this:

http://www.radiantguard.com/reflective-insulation.aspx

I also have this on the north wall and it reflects light in rather
than letting it escapes. It can also be pulled over the top, instead
of inside.

I've got some folding multilayer 1 mil mylar "storms" that has very
low light loss, but it has it's issues.

My benefit here is that while I have very little sun during the
summer, falling leaves changes all that. I may have to become a winter
gardener...

At any rate, there is a lot to consider. And I'm afraid more that the
casual greenhouse user would like to consider!

As you have said, anyone can grow in ideal conditions, it takes a
gardener to grow in what is available!

Jeff

I'll retrofit my solar cabana with mylar storms this fall. Clear
mylar degrades in UV so it needs a UV outer barrier.

I've been using vinyl shower curtain liners. They are very clear and
hold up well, so far.

Jeff

Small maybe beautiful
but one has to work harder on your design.

--
- Billy
"Fascism should more properly be called corporatism because it is the
merger of state and corporate power." - Benito Mussolini.
http://www.youtube.com/watch?v=Arn3lF5XSUg
http://www.thirdworldtraveler.com/Zinn/HZinn_page.html

In article
,
Billy wrote:

In article ,
Jeff Thies wrote:

Billy wrote:
In article ,
Jeff Thies wrote:

Bill who putters wrote:
In article ,
General Schvantzkoph wrote:

On Sun, 07 Mar 2010 12:36:25 -0700, Suzanne D. wrote:

"General Schvantzkoph" wrote in message
...
I'm thinking about getting a greenhouse this year to extend my
season
(I live in Massachusetts). Last fall someone on this group suggested
I
try a popup greenhouse because they are very cheap (under $150, some
as
low as $50), rather then make any kind of major investment. Does any
one have any experience with them?
I bought a $110 plastic greenhouse from Walmart. It was easy to
assemble. The workmanship was a little shoddy, but nothing
drastic--just
a zipper off-kilter, some crooked seams, that sort of thing.

There were two problems I saw, and these might not be problems for
you:

1. It didn't stay warm at night. I'd see seedlings popping up during
the day (when it was VERY hot inside the greenhouse), then they'd die
overnight. If you are going to put some nighttime heating in it, then
this probably wouldn't be an issue for you.

2. The wind completely took it away. We staked it down all around
AND
put concrete cinderblocks around the perimeter of the greenhouse, but
on
one windy night the entire thing was pulled up from its stakes and
blown
into a tree, where it twisted and broke. The plastic was ripped, and
the metal bars were bent and sheared clean off at some places. (A
few
of the stakes were still in the ground; the wind had separated the
poles
at the joints and lifted them away!) If you do not have a lot of
wind
where you live, this shouldn't be a problem.

I really like the idea of these inexpensive greenhouses, but for me
it
was a waste of money.
--S.
Thanks for your feedback. Both of those things are issues, I wondered
how
something that was basically a tent could stand up to any kind of
wind,
apparently they can't.
Maybe nestled up to a south facing wall with east and west protected
with a few cider blocks.

I like that idea.

You may wish to look at home made hoop greenhouses. Easiest way is to
drive rebar into the ground, and pop the hoops on the exposed rebar. You
will need to recover every few years, but the material is cheap.

One example:

http://westsidegardener.com/howto/hoophouse.html

My general advice, curves are strong and resist wind. If you can prop
this against a south facing wall you will cut your heating needs.
Greenhouses lose heat at night, and lots of it. Without added heat,
inside temperature will be the outside temp by morning if not long
before.

I'd investigate composting manure for heating. Not very esthetic, but
practical.

Before I started to garden, I found the smell of manure very offensive.
Now when I smell manure, I think of gardening.

Perhaps perhaps run pex through the remotely located compost pile and
pump the heat into the greenhouse when needed. Lot's of options.

As I understand it auto venting device is
really of import or the heat which varies a lot due to no solar mass
fries or freezes your plants. I's add gallons of water maybe half your
space to try to moderate the temperature swings.

Water is one BTU per pound water degree F. Heat loss for single layer is
~ 1 BTU/hr per square foot times the temperature difference. It adds up
to a lot of water as Bill has said. Try Drums. Other materials store
heat, but not as well as water.

Double or triple wall polycarbonate will cut the heat loss by almost a
half to two thirds.
and reduce light by 20% - 30%, respectivly. Six mil polyvinyl will
reduce light by 5 - 15%. In low light situations, this could be
important. I was planing on a hoop house, but decided that I couldn't
afford the light loss in my particular situation.

It's always a tradeoff. You could have removable insulation and put it
in at night. But that can be a hassle. I've done some removable with
reflective bubble wrap such as this:

http://www.radiantguard.com/reflective-insulation.aspx

I also have this on the north wall and it reflects light in rather
than letting it escapes. It can also be pulled over the top, instead
of inside.

I've got some folding multilayer 1 mil mylar "storms" that has very
low light loss, but it has it's issues.

My benefit here is that while I have very little sun during the
summer, falling leaves changes all that. I may have to become a winter
gardener...

At any rate, there is a lot to consider. And I'm afraid more that the
casual greenhouse user would like to consider!

As you have said, anyone can grow in ideal conditions, it takes a
gardener to grow in what is available!

Jeff

I'll retrofit my solar cabana with mylar storms this fall. Clear
mylar degrades in UV so it needs a UV outer barrier.

I've been using vinyl shower curtain liners. They are very clear and
hold up well, so far.

Jeff

Small maybe beautiful
but one has to work harder on your design.


Happy Fathers Day !
Sometimes wonder why we did it in hindsight glad I did. Sometimes I
think what is next. Ups and downs and all around as I listen to

Lir 18:10 Wim Mertens Close Cover New Age AAC audio file 100 1
8/2/09 6:03 PM 1986

--
Bill S. Jersey USA zone 5 shade garden
What use one more wake up call?
http://ocg6.marine.usf.edu/~liu/Drif...atest_roms.htm