In Season: Key limes are available year-round, which means it's also pie season all year long! Thank goodness key limes are available year-round! The Mexican or key lime -- essential for key lime pies -- grows in USDA zones 9 through 11. Key Lime Basics. Molecular data indicates that the lime’s female parent was Citrus micrantha, a Pepeda native to the Philippines. Growers reduced lime acreage just after the year 2000 due to citrus canker infection and falling wholesale prices. Thank goodness key limes are available year-round! What to Look For: Key limes are smaller than the standard Persian limes and have thin, leathery skin. Some of the other names for key limes are Mexican lime, West Indian lime, Omani lime or Bartender's lime! Imported limes supply the U.S. market, where 2007 consumption was 3 pounds per capita. Lime seeds can easily be grown as trees, but with the exception of key limes it’s hard to know what you’ll get. The majority of commercial Key limes from Mexico and Central America. While these limes were once grown in California, Texas, and mainland Florida, groves in the Keys came to dominate the market in the early 20th century because they produced a citrus unlike the rest. Bottled key lime juice can be found in specialty markets in the canned fruit aisle near the bottled lemon juice, and it's often sold online. "Bearss" limes are more cold-hardy than Mexican limes, and do not need as much protection. Because key limes can cost upwards of two to three times as much as Persian limes, it can be cost-effective buying it bottled. What to Look For: Key limes are smaller than the standard Persian limes and have thin, leathery skin. The region's uniquely alkaline soil mellowed the limes' astringency, and abundant coastal rains fueled their growth to lemon-like proportions. The growers replaced the Key Lime trees with Persian Lime trees because they are easier to grow, easier to pick because they have no thorns, and due to the much thicker skin, are easier and more economical to ship. Key limes were widely distributed by the late 1950s.