In this article, students examined how and why plants work through in-depth investigations. They performed scientific inquiry through questioning, developed models, constructed explanations, and communicated information of the structure and function and system models of plants, and then engineered a representation of their understanding. The first-grade students began learning about plants with pumpkins in October. Students examined the outside of the pumpkin, noting the parts that could be observed. Vertical cuts were made to reveal the parts on the inside of the pumpkin. These were identified, labeled, and the students created drawings of the parts. Some of the seeds were planted in the school garden. The lessons learned about pumpkins in the fall provided a foundation for an in-depth investigation of plants in the spring and allowed the students to relate to prior experiences. In addition to lessons that provided background information about plants and plant parts, the students engaged in other science investigations between October and the spring that helped them understand the value of changing one variable at a time. Ongoing observations and discussions helped the students to design investigations that promoted more learning. Reflection on learning experiences offers opportunities for students to think about how they learn best and apply those strategies to future learning.