To make a combination means to plant several complementary vegetable crops or flowers in the same row or section, which, for example, have a different cycle.
In this way, as your lettuce harvest approaches, between two heads you can plant cabbage, cauliflower, or green cabbage. Your young cabbage will start to develop, well protected by its neighbors, and it will also benefit from the almost daily watering you give to your end-of-cycle lettuce.
Once the lettuce is harvested, the cabbage can "go on its way" alone. Later in its cycle, it could also welcome another planted crop. Why not endives for your fall and/or winter production?
Now it's your turn!