Texas is an enormous state (it's slightly larger than France), so it stands to reason that many kinds of grapes can be grown here: As of 2006, there were 21 grape varieties planted in Texas. There are three main wine-growing regions (North Central, Southeastern and Trans-Pecos) in the state, which are divided into eight federally approved American Viticulture Areas (AVAs) -- designated wine-growing areas based on climate, soil, elevation and geographic features.
Growing grapes in Texas isn't easy, though. European wine grapes such as cabernet sauvignon, chardonnay and merlot are very susceptible to Pierce's disease (a bacterial infection spread by bugs that eat grapevines), which flourishes in areas with warm, humid winters. The only solution for growing these grapes in Texas is hybrids made from native grapes such as black Spanish and blanc du bois. Generally speaking, European wine grapes do well in Texas's North Central region, but the farther north you get, the winters become too cold. In the south and east where humidity makes Pierce's disease more prevalent, muscadine, cynthiana and lenoir grapes (all hybrids) thrive.
Pierce's disease aside, cabernet sauvignon and chardonnay are the most popular wines in America, so they're also the most planted grapes in Texas; merlot, sauvignon blanc and chenin blanc round out the most-planted list.
Because it's so hard to grow grapes in Texas, wineries often have to buy grapes from other growers to make their wine. We'll explain more about wine labels on the next page, but basically, if it doesn't say "Texas" at the bottom of the front label, the grapes were not grown in Texas.