HEI’s Hannah Rollin and Sarah Walker are participating in the
uCodeGirl STEM mentorship program that runs from October through May, which brings together female STEM professionals and teen girls to build a support system for academic success. Here is a recap from their latest meeting with their mentors and mentees. Follow our page for future updates on their mentorship experience!
Lights, Camera, Action
On December 4, the
uCodeGirl mentorship program held their second meeting of the season. In addition to the usual attendees, the
Twin Cities PBS TV crew from St. Paul, MN, was on site to film the session. Twin Cities PBS, in partnership with the
Bush Foundation is working on a video series that covers leadership, innovation, and overcoming challenges.
Twin Cities PBS had been following a number of past and present Bush Fellows—such as Betty Gronneberg, Founder and CEO of uCodeGirl—to learn how they interact with their communities. Some videos from these tapings will be used by the Bush Foundation’s website and social media as well as be broadcast on Twin Cities PBS. Visit their
website for details.
Developing an Optimal Tomato Plant Pot
After the speaker and college student panel sessions were completed, the mentors broke into groups for their project-based STEM program. Hannah and Sarah are mentoring a group of girls working on a project to develop an indoor tomato plant pot that will provide optimal growing conditions with little human input, such as watering, soil conditioning, growing space, and nutrients.

During this session, Hannah and Sarah educated the girls about soil permeability, infiltration, and the different soil textures to build on their current knowledge of understanding the important soil properties for growing healthy plants. They challenged the girls to think about which soil conditions would be the best for growing a tomato. After discussion, the experimental phase began.
Experimenting with Soil Permeability
The team experimented with soil permeability by filling soup cans with different materials—garden soil, sand, marbles, and fish tank pebbles—and pouring water through them to judge how fast the water flowed through each material.
After watching the water flow, Hannah and Sarah asked the girls to combine the materials in order to create a more efficient growing medium. The girls decided that a mixture of pebbles on the bottom with gardening soil on top would work best. They learned that a mixture of coarse and fine soil textures would provide optimal moisture content for growing plants.
Hannah and Sarah asked the girls to do more research on what soil texture is the best for growing tomato plants. They sent them home with instructions on how to use the
online USDA Soil Web Survey so that they could determine what type of soil they have in their backyard.
Next Steps
At the next meeting, Hannah and Sarah plan to investigate other components of growing plants such as light source, the shape of the pot, and coding for automated watering. They look forward to working further with their mentees on this project. Stay tuned for their next update!
Hannah Rollin (left) and Sarah Walker (right) are engineers who work within HEI's water resources service sector in our Fargo location.