Lowest Temperature Tomato Plants Can Withstand In Greenhouse
I have a dilemma this year. I have a small business and I grow a few thousand plants in my greenhouse a year to sell.
My propane heater is not up and running this year so I have resorted to using an electric heater. I have an airtight greenhouse that is 10x20x8 that has greenhouse plastic on it.
I need to start growing my plants in the next week or so but I am worried about temperatures. I can keep the greenhouse at about 45-50 if the temp drops to the low 20s other than that the temp will stay in the 50s at night.
When I first started growing plants 5 years ago in an unheated greenhouse my tomato seedlings in flats survived in the greenhouse unheated to temps in the low 40s without any damage. If I start to grow flats of tomatoes now, will they survive if we get a fluke night in the 20s and the greenhouse temp is a steady 45-50? The greenhouse I use has no drafts it is air tight but I am investing hundreds of man hours in seeding plants and if I lost all my plants I would be in big trouble.
I know that plants outside cannot withstand the same low temps as protected plants. I have with my own experience seen my tomato plants take temps in the 40s when I was just a hobby grower with no real damage and I have read in these forums that people have had no problem with tomato plants surviving 40 degree nights when protected from wind in a greenhouse. The day time temps are always in the upper 80s to low 90s without any heat now unless it is cloudy outside. Even then the temp doesn't drop below 65-70.
I am just looking for advice from anyone that has experience with greenhouse tomato plants and dealing with temps in the 40-50 degree range. This isn't something I expect to happen everyday, it might occur 3-4 more times between now and May, I am just looking for advice about this situation, thanks.