There are different types of yucca and the most common varieties should be able to handle winter under the cover of a porch or protected patio depending on where you live. If you live in a very cold winter area you may not need to find a greenhouse for winter storage. Instead of a greenhouse, you can use a garage, basement or indoor sunroom that can keep the plants from freezing. Don't forget you can also do a drastic pruning on most yucca plants. This means in the spring if the top growth looks ugly just cut the entire trunk back to about a foot tall and new growth will sprout from the cut end. I live in an area where we often have snow and the winter temps go as low as 10 degrees. I still leave my yucca filamentosa outdoors all winter and they have survived in pots for many years. Keep growing, Marianne Binetti