Hake a Mini Green house. Inexpensive Mini-Greenhouse You can build this raised garden bed mini-greenhouse to extend your growing season with used railroad ties for the base and some scrap wood and sheet plastic for the cover.
Kitchen garden inspiration - build an Amish cold frame. I love this clever design. No plans available (our Amish friends didn't even use plans to build our sheep barn), but there are 10 photos in this post showing construction details.