greenhouse Indoor vs Greenhouse Advice

[stc3248]

I have a few newbie questions...

This will be my first year growing variety of peppers from seed. I am usually an "off the rack" guy, but they never seem to have the cool stuff at the local nursery so...

I bought a couple seed trays and heaters and following all the wonderful advise on here I've now got all kinds of stuff popping up.
I have been experimenting with a small greenhouse I built on the south side of my house. It's only about 3x7 and roughly 4 ft high. It gets about 9 hours of sunlight a day and the temp maxes out around 100 degrees and drops to about 45 at night. I am going to try using some heat sinks to regulate the temp. I'm starting with 5 30 gallon totes of water to see if that levels it out. I also have a string of C9 Christmas lights in there for emergency frost protection hooked up to a thermocube on the roof. I have some overwinter jalapenos in there now, along with a few test seedlings. I purchased a cheap shoplight with a couple daylight bulbs, and was planning to put it on a timer from dusk till about midnight or 1 am. This would also help keep it a little warmer in there for longer since it is such a tiny space, Plus it will extend the grow time each day. I will use the totes for shelves and the light will be a few inches above the plants as is discussed in all the light related posts...

I also have a large south facing window I could use for seedlings and it gets as much daytime light at the greenhouse does.

Soooo,

How much daylight is enough? Do I need the shoplight in there, or would it be better suited inside?
Should I just grow my seedlings in the window?
What should my target be as far as temp range in the greenhouse? I'm thinking the water totes will put me around 50-55 on cold nights and sometimes warmer and from 85-95 during the day...
How much will the cold night time temps stunt their growth and is stunted growth the only potential issue...
Being in San Diego and attached to the house even if there were a power failure on the coldest night of the year...I still don't think it would get cold enough to frost in there.

Thanks for any and all input!

 

[muskymojo]

I get what you're saying about the heat sinks, but I would think that 5 30 gallon totes might displace enough air to actually make that space even hotter than the 100 degrees it is now. But there's only one way to find out...

 

[Balac]

I get what you're saying about the heat sinks, but I would think that 5 30 gallon totes might displace enough air to actually make that space even hotter than the 100 degrees it is now. But there's only one way to find out...

The water is a good temperature equalizer and will not make it hotter unless the water containers is buried.

The 3X7X4 volume sounds about good for the 5 30 gal containers as long as the surface of the containers can absorb the heat. It would be better if they were painted a flat black to absorb more solar radiation and it would also help in re-radiation of the heat at night.

Also if you put some 2X4s on the ground on edge that would help as well in heat exchange. A 2X4 at the front and back of the water container it will isolate the heat sink from the ground and allow better exchange as long as there is some air space between the containers. The ground will allow heat to "leak" into the ground if the container is touching. The air space at the bottom and on the sides will enhance the air flow and will make it a lot more efficient.

 

[stc3248]

The water is a good temperature equalizer and will not make it hotter unless the water containers is buried.

The 3X7X4 volume sounds about good for the 5 30 gal containers as long as the surface of the containers can absorb the heat. It would be better if they were painted a flat black to absorb more solar radiation and it would also help in re-radiation of the heat at night.

Also if you put some 2X4s on the ground on edge that would help as well in heat exchange. A 2X4 at the front and back of the water container it will isolate the heat sink from the ground and allow better exchange as long as there is some air space between the containers. The ground will allow heat to "leak" into the ground if the container is touching. The air space at the bottom and on the sides will enhance the air flow and will make it a lot more efficient.

Damn!!! Why didn't I think about the 2x4's they're full already! Well I decided to start with 3 instead of 5 so I could keep their long side toward the sun. Otherwise I would have had to put them in short side out. Plus, some of the plants in there are too tall to sit on the totes so it left me a little more ground space for them. I guess now we'll see! They are already a dark blue color so I didn't paint them but I might later. I'm going to watch the temp closely today its supposed to be in the mid 70's here today so were going to find out if it gets too hot pretty quick!

 

[Siliman]

Being a snewbie (2nd year) I am now an expert on greenhouse effects. LOL. I had a cheapo plastic GH just big enough to walk in, and it did pretty well. But: needed better ventilation for the high end temps. Cut a new vent and/or get a fan to keep below 90F. And needs supplemental heat for the low end: use a small portable electric heater to keep temp above 50F.

I was in good shape until La Nina presented me with a really extended cold Spring. I doubt you'll face anything like that in San Diego. Anyway, during the 6 extra weeks of cold with temps hitting just below 40F many times, the peppers that were stunted the most were ones that I held off on potting up. They not only got rootbound but were more susceptible to the cold. (Neither condition is good.) Makes sense--the larger thermal mass of a 1-gallon pot is better than a 16-oz cup. Air temp not as important as soil temp. As for effects of stunting, those plants affected grew much slower, but I still got a crop. A cold summer didn't help at all, either. I'm blaming the whole thing on La Nina, not my laziness....

You've got some great ideas that I may borrow (water totes, extra lighting). Sounds like you are off the a great start. Post pix!

 

[stc3248]

Yeah...when I say greenhouse I mean some cheap poly that I clamped together with spring clamps. If I can get some at least promising results I may invest in a "real" greenhouse. Mine should be posted in the ghetto gear thread I was reading on here the other day A pic says a 1000 words so here it is...

If you look closely you can see my ghetto Christmas light frost protection in there too. I just crack the ends a little during the day to vent...

So about my other questioin. Are my seedlings better off under a 6500k florescent set, a south facing window with about 9 hrs of light a day, or in my ghetto green house? The wife won't let me put the light by the south window either...its in the dining room, and the plants in the window are bad enough according to her. I sure wish she liked peppers then maybe it would be a different story.

Being a snewbie (2nd year) I am now an expert on greenhouse effects. LOL. I had a cheapo plastic GH just big enough to walk in, and it did pretty well. But: needed better ventilation for the high end temps. Cut a new vent and/or get a fan to keep below 90F. And needs supplemental heat for the low end: use a small portable electric heater to keep temp above 50F.

I was in good shape until La Nina presented me with a really extended cold Spring. I doubt you'll face anything like that in San Diego. Anyway, during the 6 extra weeks of cold with temps hitting just below 40F many times, the peppers that were stunted the most were ones that I held off on potting up. They not only got rootbound but were more susceptible to the cold. (Neither condition is good.) Makes sense--the larger thermal mass of a 1-gallon pot is better than a 16-oz cup. Air temp not as important as soil temp. As for effects of stunting, those plants affected grew much slower, but I still got a crop. A cold summer didn't help at all, either. I'm blaming the whole thing on La Nina, not my laziness....

You've got some great ideas that I may borrow (water totes, extra lighting). Sounds like you are off the a great start. Post pix!

Sorry should have quoted you in the previous post...

 

[Siliman]

Hey, looks good to me. My guess (guess only) is the light in the GH structure would exceed the 6500K lamps, and beat the light shining through a south facing window. You could use the lamps and window to get the plant to 6-inches or so, nice protected and warm, then move to GH also.

If you can keep it above 50F and hit several 80+ days in there with real sun for half day, I'd say those plants will thrive. In my limited experience, with the few setbacks I had noted due to cold Wx, plants LOVE those kind of structures....

 

[stc3248]

Hey, looks good to me. My guess (guess only) is the light in the GH structure would exceed the 6500K lamps, and beat the light shining through a south facing window. You could use the lamps and window to get the plant to 6-inches or so, nice protected and warm, then move to GH also.

If you can keep it above 50F and hit several 80+ days in there with real sun for half day, I'd say those plants will thrive. In my limited experience, with the few setbacks I had noted due to cold Wx, plants LOVE those kind of structures....

LOL...great minds think alike! I just got done assembling a shelf system for my lights. I placed them in front of a west window that gets indirect sunlight most of the day with about 3 hours of full in the evening. I have the plants under lights there, was going to get them up and running, move to the south window in 6" pots then outside. By that time it should be early February and I should be able to place them in the GH for about a month then in the ground under the plastic...then remove the makeshift shelter once all frost danger is past. I am still keeping some overwinter plants in there and may place a few early seedlings back in there for a comparison with what I got going on inside. I guess time will tell!
Thanks for the confidence boost. I think I got some superhots on the way from another guy I met on here and I want all this worked out on the run of the mill (but still delicious) peppers first. If my system fails on these I can run down to Wal Mart and buy seedlings to replace them. If it happened to some Chocolate Bhuts or Trinidads it would really suck.

 

[muskymojo]

The water is a good temperature equalizer and will not make it hotter unless the water containers is buried.

Hmm...How exactly would burying the totes make it hotter than not burying them? I don't think just burying some totes under a greenhouse is going to do much period without some plumbing and fans.

What I was trying to say is that 5 30 gallon totes is roughly half the total cubic feet of a lean-to that size (without plants and pots).
True or false? A greenhouse with half the air volume, but same surface area of another greenhouse, will get warmer while in the sun.

 

[stc3248]

Hmm...How exactly would burying the totes make it hotter than not burying them? I don't think just burying some totes under a greenhouse is going to do much period without some plumbing and fans.

What I was trying to say is that 5 30 gallon totes is roughly half the total cubic feet of a lean-to that size (without plants and pots).
True or false? A greenhouse with half the air volume, but same surface area of another greenhouse, will get warmer while in the sun.

Yeah...I was worried about that too! Believe it or not...the hottest day since I scrapped it together, and it topped out at 102 degrees in there and it took all day to get there. It got hotter in there the first day I put it up and I opened both ends that day, today I only had one seam cracked a little...the plants look good, at least so far. The big story is its nearly midnight and around 45 degrees outside but still in the mid 60's in there...I don't understand all the physics/thermodynamics involved but it has something to do with the large amount of energy entering the house that goes to warming the water instead of the air...I think??? I did only go with 3 instead of 5 totes though...Musky you put up a really nice greenhouse a while back right? With a chain link pipe frame and raised boxes? If That was your thread I'm jealous that thing looked awesome!