Harney & Sons: how to find the cultivation date?

I recently picked up some more of the lovely Tong Lu Black from Harney & Sons, and it got me wondering if there's a way to know for sure when this tea was picked.

Lot number is 24200, best by date is July 18, 2026. If I knew how far out they dated their black teas (2 years?) that should be a strong clue and the lot number would seem to confirm that, but I'd really like to know for sure how to read these labels. And is the date actually based on the cultivation date or just from when H&S sourced the tea?

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Bonus question: If I especially enjoy teas like H&S Tong Lu Black and Mei Leaf Souchong Liquor (aka Tong Mu Zhengshan Xiaozhonga), what else should I be looking for out there?