Plant the seeds/young plants in the garden.
Label with popsicle sticks.
Water regularly. Students can take turns to water each day.
Students can draw the plant as it grows.
Students can measure the height of the plants each week. (Radishes germinate in a week, and peas/beans within two weeks).
Make a graph with the date each time a measurement is made, and the height of each plant. Different plants will have different shaped curves.
Harvest when ready.
Radishes germinate in a week if it is warm, so can plant after spring break. French Breakfast variety worked well.
Peas, even those that "mature in 56 days" are not ready before school is out if planted after spring break. Plant indoors before spring break, watch germinate for a week indoors, then transplant into the garden after spring break. Then can get a few peas before school is out - snow peas nice to eat even when small.
Beans take even longer, so try planting indoors even earlier?