Unless you’re growing head lettuce, your greens can be a “cut and come again” crop. Instead of pulling the entire plant, thus ending the fresh salads, use scissors to cut off the outer leaves near the base of the plant. Leave the inner leaves intact and the entire plant will continue to grow. I’ve been harvesting my lettuce this way for a month and will continue to do so until the plant goes to seed.
This is what my lettuce looked like before today’s harvest:
This is what it looks like now:
Within a week, it will look like that first picture again.