Winter Lettuce: The Other Desert Rose
By David Bernal
For many of us who don’t live in Arizona, the southwest border town of Yuma is hardly synonymous with lush river valleys and green horizons of lettuce farms. Less than five minutes from the Mexican border, the desert town of Yuma, Arizona has since become the official lettuce capital of the world for its unparalleled harvests and production. While still second to California in overall lettuce production, the state of Arizona is home to some unlikely counties that are growing the best winter lettuce in the country. Yuma is so proud of their lettuce that every February or March they host their annual Yuma Lettuce Days Festival to celebrate the abundant winter harvest.
While more than 90% of our commercial winter lettuce is grown in the Arizona desert, learn from the pros why lettuce is ideal for year-round home gardening.
Winter Lettuce Planting Dates
- Empire slot: August 1 - September 30
- Winter Haven slot: October 1 - October 25
- Vanguard slot: October 26 - December 10
USDA Hardiness Zones 9-10. Although home to the warmest summers in the country, the advantage to gardening in these southern and coastal zones is the ability to grow many crops year-round, especially lettuce and leafy greens. Commercial growers throughout these warmer zones, especially in Arizona, California, and Oregon, have specifically chosen the regions because it guarantees temperate winters without fear of extended frost. Lettuce and other leafy greens prefer the cool, full sun days made possible by an Arizona or coastal winter, boasting an average of 55-70°F days during its coldest months.
Average maturity of 30-70 days. Lettuce is not a fruiting crop and does not have to wait to go to flower for fruit or seed production. Depending on the specific crop, some smaller Bibb-type lettuces can be harvested as soon as 30-40 days while larger iceberg-types may require 8-9 weeks. Tender crops such as lettuce and other leafy greens mature very quickly and are ideal for temperate winters with short days. While other crops must spend months of energy on vegetative growth and flowers before they can begin fruit production, lettuce is eaten whole and can be enjoyed long before any fruiting crop.
No insect pollination necessary. Lettuce is not a fruiting crop and doesn’t rely on insect pollination the same way that other garden favorites do such as watermelon, cucumbers, or berries. Like other herbs and leafy greens, lettuce is far more tender and delicious if harvested before the crop is allowed to go to flower. Although attractive and beneficial for the local bee population, lettuce that has been allowed to flower no longer directs energy into producing flavorful leaves but rather an abundance of flowers and seeds for next season. Desert and coastal gardeners are free to plant any number of greens and root vegetables throughout the winter because they are not reliant on seasonal pollinators.
Plant in Midsummer. Regardless of your hardiness zone, lettuce is popularly grown in succession every 2-3 weeks throughout the summer for several months worth of harvests. Growers in the warmest zones traditionally sow their autumn lettuce in midsummer so the maturing crop benefits from the cooling months towards the end of the season. To sow your winter lettuce early between August and the end of September is known as planting within the Empire planting schedule.
Plant in Late Fall. If fortunate enough to be farming in zones 9-10, lettuce seeds planted in late fall will have plenty of time to be ready for a late winter harvest. Yuma Lettuce Days Festival is held annually every February to coincide with their winter lettuce harvest. Don’t be worried if your region’s average temperature dips a little cold because leafy greens such as lettuce, spinach, and arugula prefer a chill over the heat. Winter lettuce planted in the month of October is known as planting within the Winter Haven schedule, while lettuce planted between November 1 and December 10 is known as the Vanguard schedule.
