|Product Name:Romaine Hearts||Size/Weight:12 x 3 count|
Ideal Storage Temperature: 32-34°F / 0-1°C One difference that you can often notice between the outer leaves of romaine lettuce and the hearts is their shade of green. Since the outer leaves have more exposure to sunlight, they will develop more chlorophyll than the hearts, and you will see this additional chlorophyll reflected in a richer shade of green. Lettuce was first planted in California, the lettuce capital of the United States, by the Spanish missionaries in the 17th century. Its popularity across the US did not become widespread until centuries later with the development of refrigeration and railway transportation.