How long does it take a new vineyard to yield grapes?

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Dear Dr. Vinny,
I assume one cannot plant a vineyard and harvest grapes in that first season. How long does it take a new vineyard to yield grapes?
—Garth, Cape Town, South Africa
Dear Garth,
Grapevines are typically planted in the spring, and as much as they might grow that season, it’s unlikely that they will yield grapes by harvesttime. (It's also important to note that the vines are not planted as seeds; they're usually planted as very young vines that have been grafted onto phylloxera-resistant rootstock.) The following year, a grapegrower can expect to see a lot of growth and some grapes, but that first crop of fruit usually consists of very small, sour berries that aren’t suitable for making wine. But by the third harvest, growers can expect to get a proper yield of wine grapes. In winemaker lingo, each growing season is nicknamed a “leaf.” So a grapevine will be ready to produce grapes for wine by the “third leaf.”
But not everyone makes wine with that first successful harvest. Some wineries won’t use grapes from vines younger than a decade or even older for their top wines, and until then the grapes are used to make lesser wines or sold to other wineries.
—Dr. Vinny