It’s good that you are contemplating how to handle this problem. There are unwanted side effects of using unvented plastic film and even if you do everything right the plants may be more susceptible to cold injury when they are abruptly subjected to cold when the film is removed.

I wouldn’t use a tarp either. My recommendation would be to use a heavier grade of row cover (Reemay, Agribon, etc). I use Agribon 30 or 50 for vegetable crops and you can purchase it in various sizes. Another commercial product that breaths and is very durable is Typar. With these products you get protection but air exchange is allowed.

Barrie, thanks for the response! If I got the row cover, how would I use it? Just over the plants and leave the hoop bare? I am able to go home everyday at 10 am and would be able to roll up the sides of the plastic. Our weather is wacky. It can be freezing at night but back up to the 60s and 70s by afternoon. My main concern is just getting them thru the winter.

Since you have the frame in place I would cover it and just put sand bags, rocks or planks around the perimeter on ground to keep it in place. You just leave it there as opposed to rolling up plastic every morning. It’s great for swinging temperature conditions since it lets excess heat out

One problem is wind. The row cover will billow and snag on any rough area of the fence causing it to tear. The cover I had over my caged tomatoes was so full of small tears that I will not use it another year. It did extend my fall tomato harvest by a month and paid for itself many times over.

We have secured the base! The picture i posted was getting it started. I had to put my stuff in there to see how it looked. Barrie, with the row cover, would I also need heat? I have seen post where people used Christmas lights. (I do have some old big bulb outdoor lights.) Would that be needed for extended periods of below freezing? Sorry for all the questions...

In looking at your photo my biggest caution would be to avoid condensation on the leaves and the resultant growth of fungus and bacteria. I would be tempted to put pine needles , straw, or hay around and between the pots to temper the roots from rapid temperature swings. Beyond that I would not provide any cover unless you get a very bad cold streak.

Barrie and roseguy, wanted to update you. I am using the plastic because with our weather, my plants are still growing. We have had freezing nights, but the day heats up to 65. I come home every day at 10 am and roll the sides up. I used bungee cords to hold the plastic on so it doesn't take but a few minutes. So far, so good. I am actually pinching blooms off. 10 seems to be the perfect time, that is when the sun starts shingles on the top of the house. The house has full sun until around 2, then blocked by trees for an hour, then back to full. I go out and roll down the plastic when I get home at 5:30. (Starts getting dark) I get a good breeze, but the house is protected on the north, by my house, then on the east and south by a 6ft. Privacy fence. I will probably leave it vented around the clock for the next week, Temps low at 50 and high thru the 70s.

I am happy to hear that you have a system that is working well. Unless you get a very hard freeze I wouldn't be surprised if your plants stay green all winter. Thank you for your update.

Very happy roses. You certainly have this mastered.