Students love to play in the dirt. Take ownership and plant seeds to see how they germinate. Take care of their biome. Every year I do this project my students absolutely love it. It is hands-on and incorporates, plants and biomes, abiotic and biotic factors, photosynthesis and respiration and experimentation and design. They are beautiful but they are also informational: objects for data collection and graphing. Student have to measure their growth and observe any changes they see over these next few weeks.
Some students want to go aquatic and bring in fish and tadpoles. Either way it is a great interactive, long-term observational activity teaching students responsibility. They must maintain it and collect data. They must document their findings and write a conclusion. Plus after six weeks we get to fill up our outside garden with beautiful plants and flowers.