Qualifications
The qualifications for tea plantation owners are a little fuzzy. It's not like the future owner of a tea plantation is simply the most hardworking and ingenious worker on the plantation, voted upon by all the workers in a fair and just democratic process. Sorry, but plantations aren't communes. In fact, they're fundamentally hierarchical and authoritarian. Who gets the crown is mostly a matter of chance events and good connections.
That said, you can up your odds slightly by getting an advanced degree in a field related to engineering. A good understanding of the law (and what counts as a "violation") would be helpful, too. But really, there's no education like working on a tea plantation.
Some tea plantations will arrange apprenticeships for tea-minded youngins, especially from old money backgrounds. Though each plantation will be run slightly different, these apprenticeships can last for several years. You'll learn all facets of a tea plantation life, from driving a forklift and working in the mailroom to processing the tea leaves.