You never stop learning to garden. Something new always emerges, not just about growing plants, but about working in, and in partnership with, nature. If you pay attention, you can also learn about life, whether you're an adult or a child.
My child has learned a lot from growing tulips this past two years. She's learned some important lessons that aren't spelled out like a truth revealed, but rather, that are learned slowly, empirically, observing and noticing over a long period of days, months and years what happens when you plant a seed. Or, in her case, when you plant thirty tulip bulbs.
First she learned a lesson in patience, when her bulbs took months to finally peek out of the soil. Then she learned about the impermanence of things, when her tulips eventually died at the end of the season, much to her dismay.
And this year, she's learned that after a cycle ends, another starts, when her tulips bloomed again. Not exactly the same tulips as the previous year, though they're related in some way: new flowers from the same bulbs.
(Give a child the gift of a pot, some soil and a bulb, to grow and grow again year after year, and you're giving them some powerful life lessons.)