None of these plants can tolerate freezing temperatures. But luckily, none of them were left unprotected.
my small poly greenhouse was able to protect them through the night!!
During cooler days, the greenhouse keeps my plants about 10 degrees warmer than the outside. On hot, sunny days, it can get 30+ degrees warmer inside. During the night is anyone's guess.
Since the greenhouse is really just a box made of plastic, it might technically be a "coldframe."
Either way, it was able to protect my plants and I am extremely grateful.
Outside of the cold frame, the bokchoy, sunflowers, potatoes, asparagus, raspberries, flax, radishes, peas, beets, walking onions, blueberries, leeks, and swiss chard all made it without any trouble. Half of the buckwheat died and some of the transplanted strawberries.
Luckily, most of the strawberries survived without incident and I have big bushy buckwheat living happily inside the greenhouse and it will take the place of the ones that died.
Tonight - the forecast is for weather below 27F so I am going to wrap the outside of the greenhouse with the "old greenhouse" and put the milk carton tops back on the containers. I also added a few more bricks inside to soak up whatever sun/heat they can today.
I may even add a tea candle or two for extra warmth. I know they made it through the last few nights, but I'd feel better knowing "I tried" to make it easier for them.
On a gardening update: The melons and peppers still have not germinated!! Everything else has germinated just fine inside the greenhouse (even cucumbers and squash,) so I know it's a viable alternative. I think the spate of 30-40 degree days have just made it too cold for them to come up. I did dig down and noticed the cantaloupe seeds had cracked, so the embryos are planning an escape...
The watermelon seeds are black and I couldn't locate them in the soil very quickly. I started a new batch of both melons and peppers in the house (which isn't warm enough either, lol) but I am still hopeful they can be successfully propagated without electricity in zone 4.
One potato has popped through the surface of the soil (planted 3/31, above soil 4/20.) 1 down, 11 more to go. I buried the chitted roots very deep at the bottom of the boxes and piled the soil all the way to the top. So they had at least 6 or 8 inches to get through. I noticed the little leaves right before the big frost came, and I buried them before it hit.
I will unbury them in a few days.
The asparagus is up (first arrival 4/19/201.) I reburied the spears so they wouldn't be damaged by the frost. Peas showed up around 4/18/2015. They were planted on 3/31/2015. It took 18 days to germinate and pop above the soil. The weather was warm and cold (between 25-73), kind of dry and very windy. I did not irrigate.
The raspberries are slowly coming back to life. The black raspberry floricanes have small leaves along the stem. The heritage have small leaves at the base and a few suckers.
The red summer raspberries (latham and mystery) have not budded out.
The leek seedlings were dibbed into 2 inch holes on 4/19/2015. They have transplanted successfully. The grocery store onions are still surviving and actually seem to be growing (at least the green tops.)
No fava beans or parsnips (planted outside) have shown above the soil. No sunchokes are visible yet. No new leaves on the strawberries but the older ones are perking up. 2 sunflowers have been dug out by animals. The Rhubarb was transplanted at 2 inches tall and 1 set of true leaves and seems to be holding on through the frost just fine. New walking onions keep showing up daily. I forgot how many (and where!!) I planted all of these...