It's funny and beautiful how a moment of whimsy ends up being a fulcrum point in his life.
It seems there's a lot of interest in gardening / food production among tech people. For me, one of the reasons I love gardening is because in many ways it's totally different from working inside with machines, but there are important and unexpected overlaps. For example if you have a solid understanding of the OSI model which informs your method of system design, you can easily move into gardening where knowledge of the layers of a forest plays a similar role. Having this experience in tech makes it easy to zero in on similar structural principles in gardening, learn about them, and apply that knowledge whereas many others clearly don't.
Just like a person who doesn't understand the value of a proper foundation in tech (hardware, lower protocols like DNS, etc.), a similar gardener won't first seek to build strong healthy soil, and they will constantly fight against nature rather than work with it, doing more work while getting fewer results.
As an aside, regarding onions: last year I cut off some green onion bottoms from the store and put them in the ground (including the little roots). They grew back and gave several more green onion harvests before winter set in, and now they're back on their own! Permanent green onion. You can do this with a number of plants, btw. Try it!