All right, over the last couple days, we’ve now discussed “low minimum” temperatures for plants. We’ve also more deeply understood frost and how plants actually experience cold damage.
Now, let’s thread in some “proof” to those previous discussions. It’s one thing to say something, another to demonstrate it.
Most tomato growers will not waver when they tell you that 50 degrees Fahrenheit is the minimum safe low temperature for a tomato plant. Yet, here’s our greenhouse tomatoes that have been experiencing low temperatures down to 35 degrees for the last week or so.
See any major problems from cold stress? Unhappy plants? Yeah, we don’t either. 35 degrees is just fine for a tomato plant, so long as there’s zero risk of frost. This is honestly what we see from most plants, at least those don’t crave warmth like peppers and cucumbers.
Now, we’ll admit, we’re using fairly deep and perhaps uncommon knowledge about the depths of cold climate gardening to get here. Also, we’ve done a lot of “not sure if this is safe” testing. We’ve “allegedly” frozen plants before and have definitely induced cold stress exploring actual minimums.
It’s totally understandable why someone would pick an arbitrary 40, 45 or 50 degrees as a safe, minimum low temperature. These will be very safe low temperatures. You could also pick 60, 70 or even 80 degrees and still not be wrong, but you’d also be very far from the truth.
We’re not saying you can be willy nilly with your plants and set them outside at any point. It’s important to understand that we’re doing these things under highly controlled conditions where we can safely ensure a minimum low temperature.
We’ll be providing more guidance about our actual planting efforts soon. But, the gist is we don’t start planting anything until we’re two weeks out to our expected last frost!
