What Is the Difference Between Meyer Lemons and Regular Lemons?

Regular, or true, lemons (Citrus limon) and "Meyer" lemons (Citrus x limon "Improved Meyer") are similar -- both have colorful, tasty yellow fruit, fragrant, decorative white flowers and evergreen, glossy, dark green leaves. However, they differ significantly in plant size, fruit taste and origin. There are several varieties of true lemons, most of them moderate-sized trees. "Meyer" lemon is a large bush to small tree, and is thought to be a hybrid between a true lemon and an orange (Citrus sinensis, hardy in U.S. Department of Agriculture plant hardiness zones 9 through 10).

The two most widely grown true lemons are "Lisbon" (Citrus limon "Lisbon") and "Eureka" (Citrus limon "Eureka"). There's also a variegated variety of "Eureka" (Citrus limon "Eureka Variegated Pink") with white and green leaves and pinkish new growth. Originally from India, lemons came to the New World with Christopher Columbus. All these lemon varieties are hardy in USDA zones 9 through 10.

The "Meyer" lemon was introduced from China in 1908 by plant explorer Frank Meyer. It was a popular backyard fruit tree, until its role as a symptom-free carrier of the deadly citrus tristeza virus was discovered in the 1940s, and most "Meyer" lemons were destroyed to protect the citrus industry. "Improved Meyer" is a virus-free strain introduced in the 1970s. Both are hardy in USDA zones 9 through 10.

True lemons need more room than the "Improved Meyer." "Lisbon" can reach 30 feet tall and 25 feet wide. "Eureka" is smaller, at 20 feet tall and wide. "Variegated Pink Eureka" is the smallest, growing 12 to 15 feet tall and as wide. "Improved Meyer" is 8 to 10 feet tall -- suitable for small spaces and for containers. It can spread to 12 feet wide but is smaller in containers.

"Lisbon" true lemon has numerous thorns along its upright branches. "Eureka" and "Variegated Pink Eureka" have almost no thorns. "Improved Meyer" is thornless.

Because of its orange parentage, "Improved Meyer" is sweet rather than acidic and has a soft, thin skin. When ripe, they're a golden yellow color. True lemons have a thick skin and a layer of thick, white, bitter membrane between the skin and the pulp, along with a tart, acid taste. Clear yellow when ripe, true lemons usually have more seeds than "Improved Meyer."

True lemons grow nearly all year in favorable environments, producing new leaves, flowers and fruits continuously, but are more productive in certain seasons. "Eureka" bears most heavily in spring and summer, with "Lisbon" most fruitful in summer and fall. "Improved Meyer" bears fruit year-round. It produces most flowers in spring and the most ripe fruit in winter.

All lemons are sensitive to both cold and frost. They stop growing when temperatures fall below 50 degrees Fahrenheit. Damage or death occurs when temperatures fall below freezing. The University of Florida Extension documents flowers and young fruit killed at 29 degrees F, mature fruit damaged at 28 to 31 degrees F, and leaves killed between 22 and 24 degrees F. Be prepared to protect lemons when freezing temperatures threaten. Cover outdoor plants or move container plants indoors.

As with most citrus, true lemons and "Improved Meyer" are self-pollinating. You'll only need one tree, because the flowers are self-fertile. If you're growing lemons indoors, they may not set fruit due to lack of pollinators. Use an artist's paintbrush to transfer pollen from flower to flower.