mtjag
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New Greenhouse at high altitude 8600' in trouble

Hello all. I live at 8,600' in Colorado. While I've always been a gardener, I've really got my hands full trying to raise traditional vegetables at this altitude. I recently completed a greenhouse and am having some disappointment in getting things started. Just looking for some help with various things. Currently, I have tomatoes, corn, string beans, spinach, brocolli, carrots, bell peppers, lettuce, and canalopes planted. The only things doing reasonbly well are the tomatoes and corn. Everything else is either stunted or wilting and dying. That's one problem. I also have set up a simple hydroponic system. I'm using Grodan cubes and clay pellets. I'm having trouble getting seeds to start in the Grodan cubes in a separate tray. I've planted about two dozen seeds and have germinated about 8 plants total since the first of October.

Finally, my greenhouse has a power thermostat control roof vent and I have two vents at the bottom sides of the greenhouse along with a storm door that can be vented. This time of year, the outside temps have been as low as 0 and typically up in the 40-50's during the day. My inside temps have been in the high 30's and up to about 90 with the vent fan running.

I water every other day and recently, I've started using a little Miracle Grow mixed in the water. It's doesn't seem to be helping. Also, I want to be 100% organic so suggestions would be helpful

I am looking for help in understanding why the plants just don't seem to be growing/thriving. It seems it takes about 3 weeks to germinate seeds in the dirt pots, and then they just don't grow.

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rainbowgardener
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Some pics of how your plants are looking might help (instructions for posting pics here are in New to Helpful Gardener? under Helpful Tips and Suggestions for New Members).

Off hand it sounds like your greenhouse at that altitude is having big temperature swings. You have a big mix of warm weather and cold weather crops there. The greenhouse getting down to freezing is way too cold for the warm weather stuff--tomatoes, corn, beans, peppers and especially cantaloupes. Getting up to 90 is way too hot for the cold weather stuff-- spinach, broccoli, carrots, lettuce.

So you probably need to figure out whether you are doing warm weather or cold weather crops, since you can't really have one greenhouse suitable for all of it at once. Unless you are going to spend substantial amounts of energy heating it, it would make more sense this time of year to go for cold weather crops. In which case you need to be doing a lot more venting and fan to keep it from heating up so much. Or cover some of the panels so not so much sun is coming in. Look for some of Bobberman's posts about using (black painted) 50 gallon drums filled with water as thermal mass. Soaks up some of the heat in the daytime to keep it from getting so hot, and then gives it back at night to keep it from getting so cold.

Bobberman
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Rainbow also has some good suggestions on Sweat chambers which will help your seeds sprout quick! I also have added a few stee pipes painted black extending out of my 50 gallon drums of water to heat the water quicker! & it works!

mtjag
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That makes sense about the different type of vegetables. The question is which way to go...warm weather plants or cool weather plants?

I do have 11 black barrels on the north wall that don't seem to be warming that much particularly since they get sun all day. At this altitude, we do get a lot of sun, practically every day, unless it is snowing. If it is overcast for a day, I usually suppliment with a propane heater that night if the temperature is going to drop significantly. Normally, if the sun is out during the day, there is enough heat gain during the day to keep the greenhouse in the upper 40's to lower 50's at night without the propane. The problem during a sunny day is to keep the temperature under 100. I set the roof vent fan to come on at 90 degrees at the roof level. I have two vents at the bottom on either side of the greenhouse that open automatically at 40 degrees and closes below 40 degrees. When the vent fan is running, it does a good job of sucking in cooler air from those vents as you can see the plants move by the breeze.

I'd like to know more about the "sweat chambers" mentioned by Bobberman to get fast germination on seeds.

BTW, I do have some flowers that are doing great in the greenhouse along with a lemon and orange tree that are both blooming at present. Of all the plants, the tomatoes and corn seem to be doing well. Everything else is extremely slow growing, not growing, or wilting. So it sounds like for the most part that I have enough heat?

What about watering? Should I water every other day or wait longer between watering? And, what should I use for fertilizer?

Anybody working with hydroponics in their greenhouse?

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lorax
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I can tell you that at your altitude and latitude, you should be concentrating on the warm-cycle crops in the greenhouse - namely the tomatoes, cantaloupes, peppers, and beans. The temperatures that make those plants happy however will do in lettuce, spinach, and to a lesser extent carrots and other root crops.

Does your greenhouse have a corner that feels "cooler" than any of the others? If you do, then that's where to grow the lettuces - other than that, rigging shade cloth for them may help them out. Lettuce is a constant battle at high altitudes, and it often does better in a sunny window indoors than it does in the punishing outdoor sunshine.

I'm surprised at your broccoli, though. Which cultivar do you have planted?

Bobberman
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Ho big is the greenhouse. & how bg are the 11 barrels. I would have a small fan blowing on the bottom of the barrels set to kick on when the temp reaches 60%. The fan blowing on the barrels will heat the barrels and keep the greenhouse cooler when the water in the barrels absorbe the extra heat!
+++
I would grow the cold weather crops closer to the ground and the tomatos higher up! Make all the walls white or a reflective material to give more light to the plants. If the barrels stay aroud 50 to 60 degrees or lower I would set the cold crops on top of them in boxes if possible!. I also have a few post on sweat chambers that explain how I am makig mine.. I also set insulated material between the round and my barrels!
+++
I have a A frame green house 12 by 16 connected to my old one and put a gutter on one side to catch the water and it fills a 50 gallon barrel when it rains in a few hours! I just finished that gutter last week and it workd great and is about 12 feet long! I wish I could show some pictures but have not mastered that yet!

mtjag
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the greenhouse is 12x14 and about 10' at the apex. I hadn't thought about painting the inside white for more light, but that sounds like a good idea. The barrels are 35 gallon black plastic. I did notice today that they are warm to the touch in the late afternoon, so I suppose they are contributing somewhat.

Since I am 100% off grid solar, I have to watch carefully the amount of electrical usage. As long as I can run it during the daylight and turn it off at night, it should not be a problem. I will put one in there tomorrow.

Currently, I have all my plants in pots sitting on the floor. Sounds like I need to build some shelves on one wall to get the tomatoes, beans, canalope, and bell peppers off the floor.

Bobberman
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Every little thing helps. The metal in the water barrel I think will warm the water quicker and give off more heat at night! If the barrels set on the ground they will loose heat fast so put something under them like 2 inch styrofoam or any type of foam insulation! that is not effected by moisture!
+++
Another thing I do is use something clear or a screen for my counter tops so the light would hit what is below.and warm it up and also keep things from mold! I got some heavy freezer shelves like in the grocery stores about 6 feet long and use them for shelves! Use a syphon hose to drain most of the water from the barrels to raise them up! I hope something will help!

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Gary350
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I use to build and sell solar panels and solar green houses in the early 1980s. About 50% of the suns heat is lost through 1 sheet of glass. About 5% of the suns heat is lost with 2 sheets of glass. About 2% is lost with 3 sheets of glass.

All your heat can be lost if you have air leaks. On a very dark gray over cast day cold 10 deg F and a little windy a solar panel or green house should warm up to 70 degrees F. The exact same conditions 10 deg and windy but full sun the green house should warm up to 100 deg F.

I had several 55 gallon black barrels of water in the green house they only warmed up 2 degrees during the day and lost 1 deg at night in the summer. In the winter it was just to opposite warm up maybe 1 deg in the day and lost 2 deg at night. A water pump with a radiator and a fan give better heat transfer and the barrels would warm up 20 deg every day in the winter and 85 deg in 1 day in the summer.
Last edited by Gary350 on Tue Nov 29, 2011 6:12 pm, edited 1 time in total.

Bobberman
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Good info. Thanks!

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rainbowgardener
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Those are black metal barrels, right Gary? The water is the thermal storage, the barrels are just to contain it. So you want as much of the heat absorbed (why it's black) and transmitted to the water as possible. The plastic is too insulating, doesn't transmit the heat. I don't think plastic barrels would work very well at all for this application.

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Gary350
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Yes my barrels were metal and black but plastic barrels will work. I had 3 barrels setting in a row about 2" from each other in a small 8' green house. Even if the water temperature in the barrels was 90 degrees F if the temperature outside dropped to 25 deg F it would be 26 deg F inside the green house. The barrels would not release enough heat to keep the green house warm.

In the winter daylight hours are shorter the sun made heat from 8 am to 4 pm. That is 8 hrs of heat compaired to 16 hours or no heat. The system must be able to take in 16 hrs of heat storage during 8 hrs of sunlight.

I had a radiator in the bottom of each barrel. I ran copper tubing from the pump to the first radiator, then to the second radiator, then to the third radiator, then back to the pump. I used a $4 Snap Disc Thermostat like the ones you find inside an electric clother dryer to turn on the water pump. The 70 deg F snap disc was mounted to a 12" square of sheet metal painted flat black. When the sun warmed up the sheet metal plate the pump motor came on and would automatically turn off when the sun went down. On a sunny day even if the temperature was in single digits the water would warm up to 95 to 100 deg F. The barrels were full of water and I poured 1/4" of oil on the top surface of the water to keep it from evaporating away.

I had another 45 deg F thermostate that would turn the pump on again after dark when the temperature dropped. This also turns the pump off at about 48 degrees other wise the pump will run non stop and dump all the heat from the barrels into the green house then it will be 100 deg F inside there. If you dump all the heat too fast then about 3 am there is no heat left then your plants freeze to death so you need to have enough barrels to hold enough heat for 16 hrs of darkness. The thermostate needs to work like your home thermostat where it cycles the pump on/off and tries to hold the tempature in a certain range like 45 deg or what every you like.

I started out with 1 barrel there was not enough heat to last all night so I added another barrel. 2 barrels were better but the heat ran out about an hour before the sun started to come up so I added a third barrel.

Check out the link to this water pump https://www.ebay.com/itm/130-GAL-PER-HOUR-FOUNTAIN-PUMP-/380389840979?pt=LH_DefaultDomain_0&hash=item5891005853

This pump will work fine. You can also build a water fall system for heat transfer. The only bad thing about a water fall system is you get a lot of evaporations so you have to all the time be adding water to your barrels.

mtjag
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Wow, that's lots of great information. I'm curious about the radiator in the bottom of the barrels. What kind of radiator is this and do you connect them all through the top of the barrels?

Since my last post, we have had several nights with temperatures in the single digits. I have been monitoring my greenhouse and find that I'm having to burn a small propane heater for about 30 minutes in the evening and by morning when the sun comes up, the temperature is usually around 40 degrees in the greenhouse. On sunny days, when the temperature at night is in the 20's, I don't have to do anything and the next morning, the temperature is usually between 38-40 degrees inside.

I have put a fan in the greenhouse and run it while the sun is up. It seems to help distribute the heat and I've notice the barrels actually get hotter during the day. It does appear the barrels are releasing the stored heat through the night, but I can see that if I linked them with a pump and an inside radiator, it would be much more efficient.

At this time, my corn, beans, tomatoes are doing really well. The tomatoes are putting on lots of blooms and tomatoes. Everything else is just hanging on as it has been, with the other exception of flowers which are doing good. My hydroponic DWC is also doing well. I have spinach and bell peppers started there and they are growing, just not as rapidly as I expected.

All in all, the greenhouse is doing ok in this harsh environment despite the requirement for supplimental heat occasionally.

Bobberman
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I am working on a similar system but my system only has radiators on the outside and none in the barrels! I will have two outside radiators in the greenhouse connected to three barrels! The water will be pumped into the 50 gallon black barrels. The barrels are connected to each other by syphon hose so the water height remains the same in all barrels. One barrel receives water from the roof of the greenhouse and keeps the barrels full. The barrel that gets the roof water is 2 inches higher that the other two barrels so its the one that over flows and runs away from the greenhoue floor to the outside!+++
My pump hose is connected to three hoses each to a seperate barrel! All hoses go from top to bottom of barrel no holes needed! I have two nice size cast iron radiators. My option may be to add a 10 foot section of basboard heat at the base of the north wall!. Base board heat instead of radiators will also work and will absorbe heat quicker if put in the sunny area above growing area!
++++
Another method that would work great in my opinion is about 400 feet of black hose on the north wall that has water pumped through to all three barrels. This would have the same effect you see when you turn on a hose setting in the sun and see how hot the water can be in as little as 10 nminutes!. Black or dark green plastic absorbs heat fast wether in the sun or in a hot area! +++
Heating the barrel water is the goal no matter how you do it doing the sun heat time of the day! Collect as much heat as you can to be released at the cold time of the night! There is no need to wast free energy with all modern ways we have to collect it! Thats my 2 cents!

DoubleDogFarm
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Ok, Here is my radical idea.
[img]https://i67.photobucket.com/albums/h300/eric_wa/1%20DDF%20-%20Helpful%20Gardener%20Misc/Greenhousewoodboiler.jpg[/img]

Build a water trough out of concrete block. This trough is part of the north wall and full length. Inside this trough is a wood fired boiler surrounded by water. Now build your greenhouse over this.

I'm thinking the tank / trough could be open and raise fish, while heating the greenhouse. You could also seal the tank / trough and raise the temperature to heat the greenhouse and maybe your house or shop.

Many details to work out.

Eric

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Gary350
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I used small heater radiators from a car inside the barrels. I used car heater hose to connect all the radiators together end to end. I have copper tubing running from the radiators to the pump. There is a 4"x24"x30" air conditioning radiator in the copper tubing line with a fan this radiator is used to pick up heat during the day then release heat at night. All the barrels have the tops cut out so I had to pour some oil on the water surface to keep the water from evaporating away.

Before that I tried a syphon system from barrel to barrel. I pumped water into the first barrel then pumped it out of last barrel. The syphon system gave me a lot of trouble so I switched to radiators in the bottom of each water barrel.

valley
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mtjag, Wow! 8600ft. I thought I had a special situation being at 6800ft. Good luck to you with your growing. You must get a great deal of snow as we do here, do you plan to keep the greenhouse going through winter? Here we are not able to.



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