Its the end of the growing season, do I need to pull up the plants or are they perennials?
Certified GKH Gardening Expert
If you are in an area that never experiences a freeze then it will remain a perennial. If it does freeze in your area, then I would recommend pulling them out and replanting. Here is an article for more information on the plant: https://www.gardeningknowhow.com/edible/vegetables/tomatillo/growing-tomatillo-plants.htm