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.
This is the easiest way to sprout seeds with kids - with some great tips too. This science experiment is great for demonstrating seeds germination and observing roots and sprouts. A great way to get kids excited about nature learning and the garden!