Romaine or cos lettuce is a variety of lettuce that grows in a tall head of sturdy leaves with firm ribs down their centers. Unlike most lettuces, it is tolerant of heat.
Plant a month before the last frost. Plant in spring or fall. Put lettuce seeds right on top of the ground, cover very lightly. You should plant the seeds 4 inches apart. It’s ready to thin when it grows to about 3 inches. You can grow it outside and it doesn’t need a trellis or any support. It takes 7-14 days to germinate and 65-70 days to grow.