Desert plants(Hardy Cacti and Agave) In my desert garden I cover my plants with old glass window panes, cold frames, or whatever I can find I am all for being creative and resourceful. I even use Bamboo from my bamboo grove to create a frame that I put clear window plastic over to help protect some of the cacti. Cacti and Agave hate wet weather many can take the cold but cannot do wet cold they tend to rot. So in the middle of October here in USDA zone 6b I cover up my desert bed to let the bed dry out and to keep the rain off before the cold sets in. I cover everything in 4ml window plastic to keep out the wetness.
Hardy Palms With my hardy palms Chinese Windmill Palm (Trachycarpus fortunei), Sabal minor, and Needle palm (Rhapidophyllum hystrix) I use this method. I use a large tomato cage put over the palm wrap the tomato cage in several layers of bubble wrap then stuff with dry leaves and or straw. Then I put a plastic heavy duty trash bag over the top of this and then use twine and tie tightly around the tomato cage to keep the plastic on. You will probably have to use duck tape or heavy duty packing tape to keep the bubble wrap from flying off if it gets windy, they can unravel. After established(after 2 years) the palms may survive without protection depends on your climate and moisture and the species of palm. Needle palms and Sabal minors are very hardy and more tolerant of moisture than other palms. Many palms can rot during wet cold weather. There is a group of Windmill palms in Bulgaria that have survived for many years unprotected in very cold temperatures, but these may be more cold hardy than many other strains of Windmill palms. It's all an experiment really.
Here are some photos of my winter protection from this winter.
