Around midnight it was still over 40 in the hoophouse. This morning we woke up to ice cold wind, the low in the hoophouse was 23 F and the greenhouse got down to 30 F.
I had just taken a flat (50) of  nasturtiums to the hoophouse and added a few to the tray I’ll take to “Our Place” tomorrow.  Most, but not all, looked rather frozen.  However, the nasturtiums in the ground looked fine:

3/2/12 The rocks kept the seedlings warm

A few weeks ago I stuck some seeds in the ground and those seedlings look just fine.  Here’s the SE corner with in ground seedlings:

3/2/12 more survivors surrounded by pots and Lolo Biendo lettuce


Interestingly, I looked up both Kingman and Meadview at weather.com and the observed low for last night was 38 F.
We were 15 degrees colder.
And today we received a cold front warning, so we’ll be covering the sensitive plants in the greenhouse.  All the peppers, eggplants and tomatoes from last year are in the greenhouse now.  They all look good so far.  I brought the nasturtiums back up, maybe some will recover:

We know that it wasn’t that cold for very long because the hoophouse was still above 40 F around midnight.  We had NO idea it could get so cold.
The reason I started so many nasturtiums so early is that they’re supposed to be great trap plants, attracting the aphids away from the veggies.  Last year we had nasturtiums in the southern raised bed, but apparently we planted them way too late and they barely flowered by the time it froze in fall.
Also, the leaves tasted GREAT in salad, just a bit spicy.
So I decided to get an early start this year and to do some experimenting.  Since this is the first year with the hoophouse, we’re just trying to see what will live and what will die, how hardy our plants are.
It is amazing that the nasturtiums in the ground look so good.   I’m certain that they would not have lived outside.  The night time temperature is about the same, but in the hoophouse it gets well into the 90s during the day and the plants are protected from the ferocious winds.  It’s hard to believe what a huge difference that plastic makes.