My cold frame

[Daniel_NY]

[digitS']

Wow!

With a set-up like that, even I might have been successful with a cold frame back when I made the attempt!

I'm not even sure what was available for us during those days. There was glass and wood . . . I'm not sure if I ever got much beyond that.

Daniel_NY, it is an extraordinary cold frame and you seem to be experiencing high quality performance.

Steve

[hendi_alex]

Really well planned and executed cold frame. If mine, would probably have opted for brilliant white interior, so that plants benefit more from the scattering of light. Better yet, would consider placing foil wrapped foam board inside, thereby getting benefit of reflective surface, plus extra R value as well. The other thing that might be worth a future upgrade would be to place one or two window panels on the south side. Might as well maximize the amount of light after having invested so much effort and expense in building the cold frame.

Your cold frame should really pay off, helping you to extend you growing season. I love my two small portable cold frames which allow me to move plants outside many days in January and February. There is just no substitute for natural sunlight when trying to growth healthy, stocky transplants.

[Daniel_NY]

Steve and alex, thank you for your nice words.

> If mine, would probably have opted for brilliant white interior…

Good idea. Most likely I’ll do it. Thank you.

>Better yet, would consider placing foil wrapped foam board inside, thereby getting benefit of reflective surface, plus extra R value as well.

I thought about that, but I planned my cold frame, for spring, not for winter. But nevertheless I’ll keep in mind your suggestion.

>The other thing that might be worth a future upgrade would be to place one or two window panels on the south side.

But right now the cold frame is oriented South. I have sun from 8:30 am to 5:30 pm. Or am I missing something here ?

>Your cold frame should really pay off, helping you to extend you growing season.

I only planned the cold frame for making seedlings and to harden off the small plants. I'm sure this year I will not be late.

>I love my two small portable cold frames which allow me to move plants outside many days in January and February.

Good idea a small portable cold frame.

>There is just no substitute for natural sunlight when trying to growth healthy, stocky transplants.

True that.

[hendi_alex]

If you are just using the cold frame in the spring, then the gain of light from the south wall would probably be minimal. During the winter, when the sun angle is low, the light would be hitting the front wall more than hitting the angled top glass. During January-March or so, the sun angle is wrong, and would be hitting the glass at less than 90 degrees and would be hitting the south wall perhaps more head on than the top surface. Both of these issues would dramatically limit the light and heat entering the greenhouse.

[Daniel_NY]

>If you are just using the cold frame in the spring, then the gain of light from the south wall would probably be minimal.

MINIMAL ? I'm sorry I don't understand. If SOUTH wall is… minimal, which direction is… MAXIMAL ?

>During the winter, when the sun angle is low, the light would be hitting the front wall more than hitting the angled top glass.

That is true, but the angle of the roof is pretty big, so I think I’ll still have light.

>During January-March or so, the sun angle is wrong, and would be hitting the glass at less than 90 degrees and would be hitting the south wall perhaps more head on than the top surface.

That is also true.

>Both of these issues would dramatically limit the light and heat entering the greenhouse.

I don't know about “dramatically” but it’s true again.

So, what’s the solution in your opinion ?

[hendi_alex]

The south wall is opaque, I.e. no light transmission. The top is angled to the south, but is angled far less than is required to receive the sun directly. So during the winter, the sun strikes your glass at and angle and most just bounces off. Also, only about 50-60% of the glass surface area actually receives the equivalent of direct sunlight, because the angle is wrong for the winter time sun position. During the winter, the south wall, which has no glass, actually receives more direct sunlight than the glass surface on top. What I'm saying is that with most cold frames, the front, the sides, and the top are all made of transparent materials so as to maximize sunlight and heat. If trying to maximize sunlight during the cold months, when the sun is low in the sky, you might consider replacing the front opaque panel, with a transparent material such as glass or twin wall poly carbonate. But if, as you say, that you only use the cold frame in mid to late spring, the benefit of doing such may be marginal, as by then, the sun angle is well above its winter time lows, and during April and May is striking the top transparent lid more and more directly as spring proceeds.

If by measurement, or by pant growth result, it is evident that the cold frame is receiving enough light, then obviously there is no reason to make any kind of change.

[Daniel_NY]

Errrr... but I AM using transparent twin wall polycarbonate. Please see the first three pictures.

Actually I should study deeper the subject. For the moment I simply wanted a place for my tomato seedlings. But thank you for the info. I'll keep in mind.

[hendi_alex]

Yes you are using polycarbonate on the top, but not on the lower front panel, which is some opaque brown material. I did a brief google on the subject and most suggest an angle of your latitude plus 15 degrees, or for your area around 55 degrees. You can't do anything about the angle of the top now, but if you choose, can change the front panel out or can insert polycarbonate panels into the lower front panel, in order to get more light from the south.

[hendi_alex]

I'll not bother you any more, as we seem to be mis-communicating. It really is a very nice cold frame, and will likely serve your needs as intended.

[Daniel_NY]

>I'll not bother you any more,
You do NOT bother me. I learned a few things from you.

>… as we seem to be mis-communicating.

> you might consider replacing the front opaque panel, with a transparent material such as glass or twin wall poly carbonate.

Sorry, my bad, I didn’t read carefully FRONT OPAQUE PANEL (which is ½’’ painted plywood)

I think you know by now, that English is not my native language, so, sorry again for my missunderstanding.

[digitS']

It is a super frame! And, there is good information here.

My experience with a cold frame wasn't too great. I blamed it on having so little air volume. There was no automation to it.

Drawing from that experience, I built a backyard, lean-to greenhouse. A few years later I replaced it with what is essentially a "sunshed." A sunshed is really something of a "walk-in cold frame."

When I built it, I asked the local utility people about the angle of the south wall. The idea was to use it thru the winter, something I never did. The market went out of business where I'd hoped to sell the winter-blooming potted plants I intended to grow.

The insulated roof is already shading the back edge of my middle bench but that's okay. There are only a few more weeks for me to make use of the sunshed. It has served a good purpose for 17 years now.

Steve

[Daniel_NY]

>It is a super frame!
Tx.

>And, there is good information here.
Yep, Alex was so kind to share with us some technical things. Tx Alex.

>My experience with a cold frame wasn't too great.
Well, maybe your next cold frame will be a success.

>The insulated roof…
I also planned to insulate the lid inside, but it’s pretty warm at night, so I gave up. But if I will use the cold frame during the winter, FOR SURE I will insulate the lid.

[Daniel_NY]

Yesterday my seedlings looked like this:







Today they look like this:







What happened was a malfunction of openining the lid – not Univent’s fault, my improvisation’s fault, trying to open bigger. Few hours later, when I came home the lid was closed and 137’ F inside.

What do you think I could do?

[Dillbert]

water them modestly; keep at cool temp (50-60'F)

and while waiting for them to maybe recover,
a double for yourself.

what a bummer. my symps.

[applestar]

Oh, no.
I hope they recover.

[hendi_alex]

Not much help this time, but when night time temperatures stay above low to mid 40's, I keep the lid open a couple of inches both day and night. That will make the plants a little more hardy, and will prevent possible disaster from over heating as well.

Sorry to see your lovely plants in such distress. Sometimes they will perk right back up with little or no damage. Yours are looking pretty sad though. Add the water and keep the fingers crossed.

[hendi_alex]

Most years, including this year, I pick up some inexpensive plants in a mixed flat from the nursery, about $13 per flat. The plants are immediately up potted to one gallon nursery pots. The plants will quadruple in size in about two weeks, and will just about catch up with the seedlings that were started much earlier. I use these as insurance plants, replacement plants, and to increase the number of varieties that are being planted. Rather than totally relying on your plants to fully recover, a trip to the nursery for some 'insurance' plants might be a much safer bet for having some healthy plants to go into the garden.

[Daniel_NY]

@ Dillbert
>water them modestly; keep at cool temp (50-60'F)
got it!

>and while waiting for them to maybe recover, a double for yourself.
yeah, well.

>what a bummer. my symps.
Tx. hopefully everything will be fine.

@ applestar
>I hope they recover.
Mee too.

@ hendi_alex
>… when night time temperatures stay above low to mid 40's, I keep the lid open a couple of inches both day and night. That will make the plants a little more hardy…

Alex, right now in the cold frame is 56’F, and it can stay like that during the night tx to the bulbs which warm the air inside. Do you think that 56’ F is too high tonight ? Right now – 9 pm – outside is 54’ F, and the lowest tonight will be 44’ F. Should I open an inch or two the lid? From 137’ F at midday to 50 at midnight… isn’t that a too big difference?

[hendi_alex]

My routine:

Temperatures in the 50's and sunny. Plants are moved into the closed cold frame, but with a heat lamp.

Temperatures in the 60's and sunny. Plants are moved into the closed cold frame with no heat lamp.

Temperatures in the upper sixties or higher, the cold frame is opened during the day.

Plants stay in the cold frame overnight as long as inside cold frame temperatures will stay above 40 degrees. Plants are moved inside the house, if closed cold frame temperature may drop below 40 degrees.

Cold frame is left open both day and night, any time night temperatures stay above 45 or so.

The temperature sensitive automatic lid opener is nice, but why rely on that when the temperatures stay above 45 degrees? The opener is just another mechanical device that can fail to work properly and lead to plant loss. My inclination would be to disable the opener/closer after danger of cold damage is past.

I have an automatic lift for the cold frame lid, but have chosen not to use it, as there is only a brief period of 2-4 weeks when it would be useful anyway.

[joed2323]

daniel- Holy wow... I'm very sorry for your troubles...

The pictures from before seeing how healthy the plants are doing then seeing the recent picture is very shocking I almost wanted to cry and they arent even my plants

What happened, did the lid blow shut or did someone purposely close the lid on you knowing, (haha) these plants will cook to death...?

The good thing, usually tomatoes can bounce back from near death

I hope they make a full recovery fast, otherwise id stick a fork in those and call them done

[Fourspot]

Sorry about your seedlings. I've cooked my plants before. It gets dangerous during Spring time when we get random warm days. Even with auto vents, you really have to be on top of it sometimes with venting properly. It's so easy to forget when you leave for work in the morning when it's chilly out and come home later in 70 degree weather. Probably best at this point to buy seedlings at your local HD or nursery.

[jal_ut]

Few hours later, when I came home the lid was closed and 137’ F inside.

What do you think I could do?

I would have a fan that mounts in the wall, an exhaust fan if you will, on a thermostat to run when the temp hits a point. You also need a self closing louver on the other side for intake air. I had a set up like that in a mini greenhouse at one place I lived. The fan always kept the temp within safe bounds.

Nowadays, I am too lazy, and just buy the few nursery plants I need.

[Daniel_NY]

Back to square one:

[Dillbert]

well, on the bright side, it's a good looking square . . . (g)

I'm gathering up old blankets and sheets - we're having a late frost this year . . . as in _tonight_!

[Daniel_NY]

Dillbert, how was the late frost in your area?

Here in Long Island we had like 45’ F.

Pretty cold compared to almost 70’ F during the day.

[Dillbert]

depending on which weather service . . . prediction was 32 or 29'F -

the min/max on the porch registered 34 - didn't hear much local chatter about it so I think we dodged a late bullet here (g)

set out tom/pepper yesterday - it's time!

[hendi_alex]

This is such a nice cold frame, I'm posting mostly to take the thread back to the top of the recent posts. After all, now is the time to be planning for a seed growing area, a cold frame, or perhaps a new greenhouse. If interested, go back to page one and look at the detailed photos of this excellent cold frame.

[evtubbergh]

Hi Daniel_NY

Your cold frame is very cool. No pun intended.

I really like the look of your pots though, what are they? They look like they are recycled paper and you could plant them in he ground as is.