Greenhouses. Ziplock bag, wet cotton balls and seeds. You can see all the plant parts. This has a printable for the "house". Although I think I might just tape the bags to the window and have a lot of them.
Four season tree by a second grader. (My second graders apparently do not know what a tree looks like. sigh. Wish my four seasons pick looked ANYTHING like this) PS great idea for second grade it aligns with their science curriculum