I have a small plant ib a plastic cup. This was started from sood by a 5th-grader. I need to transplant it soon. The boy told me this is mustard, but I am not sure The leaves are small, less than 1/2 inch n diameter. Some are heart-shaped. They grow in goups of 3 on the ends of the stems. The plant is clumpy, bushy, and delicate.
If it is mustard, I probably should plant it outside. If it is not, I should probably put it in a medium pot and keep in inside.
Thank you for helping me ID this plant.