Hi Nancy, If you need a cold frame will depend on your temperature. A cold frame is meant to protect from freezing temperatures in winter. I have never grown red yucca, as it is not native to Eastern Canada, so I can't really comment on specifics for that plant, but after doing a quick google search for red yucca I see that it grows to a height of 4-6 feet. A cold frame is only ever a few feet high, so this plant is likely not suited for one anyway.

Hi Cécélia, I don't have a thermometer in my cold frame, though i suppose you could simply go an purchase a refrigerator thermometer and hang it inside. Keep in mind opening the frame would cause the temperature reading to fluctuate though, especially in winter. If you can find a digital one with a remote display that would probably be ideal.

While I can't lift mine away completly, I'll be removing the lid and using it as a raised bed! The drip irrigation is a cool idea eh! I havn't done it myself but next year, I'm going to try and hook it up to my rain barrel!