High Tunnel Gets Colder Than Outside

[KarenO]

The only kind of heater that can be safely used in an enclosed space without proper purpose made and installed venting is one that is electric.
Anything that burns any fuel of any kind including wood requires a source of fresh air and venting to the outdoors.
Truly you can die never mind the plants.
People die in every winter storm from doing things like cooking in an enclosed space such as a garage on a propane bbq.

Karen

[clkeiper]

really, they make furnaces specifically for greenhouses. propane or gas. I bought a big one for one greenhouse as back up and a small wall mounted one from TSC... ventless for the small one. along with haf fans for air movement. which would be far safer options than trying to use a torpedo heater.

[Cole_Robbie]

I looked at greenhouse heaters at a recent auction, but even at auction prices, they are out of my league.

I actually have an out-building that I built to contain a wood-burning furnace, which was my original design. I just need to re-build the ducts. That shed doesn't even have a front door, and would get plenty of fresh air to keep the heater lit. I'm never inside the greenhouse when the heater is running, so I am not worried about breathing the air. It just needs to be clean enough to not kill my plants.

Curious side note - I had sprayed Met52 on my aphids, and thought they were all gone, but they had started to come back. After I ran the heater for two nights until it snuffed itself out each night, there is not a live aphid to be found. It worked better than the Met52. I guess I suffocated them. I still have a few whiteflies, though. They must breathe less.

[clkeiper]

Originally Posted by Cole_Robbie

I looked at greenhouse heaters at a recent auction, but even at auction prices, they are out of my league.

I actually have an out-building that I built to contain a wood-burning furnace, which was my original design. I just need to re-build the ducts. That shed doesn't even have a front door, and would get plenty of fresh air to keep the heater lit. I'm never inside the greenhouse when the heater is running, so I am not worried about breathing the air. It just needs to be clean enough to not kill my plants.

Curious side note - I had sprayed Met52 on my aphids, and thought they were all gone, but they had started to come back. After I ran the heater for two nights until it snuffed itself out each night, there is not a live aphid to be found. It worked better than the Met52. I guess I suffocated them. I still have a few whiteflies, though. They must breathe less.

that is interesting. I just picked my last greenhouse with peppers in it yesterday and the new blossoms were LOADED with aphids. I sprayed them all with soapy water and since there are no benificial bugs to be found around here at this time of year I dusted them with sevin. I DO NOT want a colony of aphids in there wintering over. I have no hope of harvesting fruit so I am not worried about that... I just don't want the aphids!

We bought a small gas heater (ventless) at TSC and I am pretty sure it was less than 200.00 (which we installed ourselves... gas line and tie in). that is not too bad. if you are selling the plants from your structure they should be more than enough to cover the cost and pay for itself in less than a crop. you have beautiful plants. make sure you are not selling yourself short and not making a profit.

[Cole_Robbie]

Thanks carolyn. I battled aphids all summer. Sevin dust is pretty worthless, in my experience this year. I had plants that were doused in sevin dust and yet still had an infestation of aphids at the same time. They just crawl around it. I did not try sevin spray. That might have worked better.

Now I just need to get rid of the whiteflies. I have a lot of pots to over-winter.

[clkeiper]

have you tried benificials? green lacewings or if nothing else lady bugs? They (whiteflies) will winter over in your greenhouse on live plants and weeds. is there anyway to clean out the house of all plants and freeze the entire structure for a few days this winter? start over with new clean plants. otherwise I suggest a systemic insecticide on everything to hit them all. even the weeds if you have even a few, but those need to be out of there no matter what. pull them and get that "habitat" eliminated.

[clkeiper]

Originally Posted by Cole_Robbie

Thanks carolyn. I battled aphids all summer. Sevin dust is pretty worthless, in my experience this year. I had plants that were doused in sevin dust and yet still had an infestation of aphids at the same time. They just crawl around it. I did not try sevin spray. That might have worked better.

Now I just need to get rid of the whiteflies. I have a lot of pots to over-winter.

Yah, I read that after I dusted. I thought I would check... erp! A few people said it didn't even faze them. well, in anycase.. it is done. I should go check to see if the aphids are dead and respray with a hose end sprayer if not.

[Cole_Robbie]

I'm out in a big field, and I feel like the entire property is infested with bugs. I haven't used beneficials. Met52 has been great for controlling the whiteflies. It's just hard to kill them all. I can try malathion. I don't use it, mostly because I have a bee hive adjacent to the greenhouse, but the bees don't fly below about 50 degrees F.

I can't find much about the technique, but a high enough temperature will kill anything. I could try taking out the plants on a sunny day, then seal up the greenhouse and turning on the heat. If I could hit 130 or so, that should take out the bugs.

Here is a link with some research to heat shock of whiteflies:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3061596/

[clkeiper]

well, that will kill the bugs inside but when you bring the plants back in you will re infest the house with the whiteflies that were taken out on the plants and brought back in. that is the object of a systemic. very effective in the Winter when there are no "good" bugs to damage. You do not want to use malathion where the bees can get a drift of it. what are you using to apply your sprays with? that might make a difference. are you completely covering the entire plant with the product. we use a back pack sprayer with an engine outside and a 3 gallon back pack "hand pump" sprayer for inside. turn the nozzle so it is pointing up towards the foliage from underneath while spraying, too. You need to cover everything. and do you put in a few drops of spreader sticker? that makes a huge improvement on effectiveness. I don't use met52 ... these are just tricks and tips we have learned over the years that work for us. is met52 a contact spray or does it have a residual effect? check to see what the Ph of the effectiveness of the spray needs to be at in order to be most efficient... if it matters... check (and change if need be) the Ph of your finished product before spraying it.

[Cole_Robbie]

The sticker in the spray is a great idea. I bought a small bottle, but have not tried it yet.

Met52 is a fungal spore that is a disease organism for the bugs. It requires a direct hit, but does have the residual effect of the disease being contagious. That contagiousness relies upon a dense population, typical with whiteflies. What happens, I think, is that the flies die down to a low enough density that they don't transmit the spores to each other, then eventually come back. No spray seems to work forever. I have just a cheap 1-gallon pump sprayer.

[clkeiper]

get a better sprayer. a backpack 4 gallon one is far easier to get better coverage with. the ergonimcs of it is just better for you and for spray coverage. it is a good investment. I see they are 80.00 in the Yoders catalog. probably a bit more at a box store but it will serve you better than the 1 gallon sprayer. no stopping a starting skipping coverage as you stop to pump it up.

[Cole_Robbie]

You're right. I hate spraying so much that I am in denial about it.

My outside air temperature is 24 degrees right now, at midnight. I just went to the greenhouse and it was 33 inside. That's not too shabby for having just a single layer of plastic. My thousand gallons of water, half of which is in black open bins, helps a lot, especially after a sunny day like today. I don't seem to be experiencing any colder temperatures than outside.

I turned on my heater, and rigged up a 2' x 4' open window for it to draw fresh air. I think it should at least not shut off this time. There is no wind at all, so that help keep heat in despite the open, ground-level window.

[natural]

I recently purchased a solo 425 backpack sprayer for $79. I have an old one that I have used for more than 5 years.

I have used a spreader sticker for years and it really helps when you need residual coverage. I use ThermX370 (yucca extract). It only takes a few drops per gallon. Some of the stickers will generate quite a bit of foam. I make sure not to add more than the directions indicate.

Bill

[ddsack]

Cole Robbie, I remember Hudson_WY was posting a while ago about using sulfur fumes periodically in his greenhouse to control insects. See his comments in this thread, http://www.tomatoville.com/showthrea...r+vapor&page=4
post #54, and especially post #60 with pictures of his equipment.

[4season]

I think pyrethrin or the synthetic analog permethrin will kill aphids. If I remember correctly some military clothes for jungle use are lightly infused with pyrethrin, low toxicity to mammals but bad for aquatic life.