Should have occurred to me last spring when tiny lettuce seedlings sprung up seemingly from nowhere. Well actually my lettuce plants from the previous fall went to seed and there you go. This year I also have spinach and mustard now well underway. Seems there is such a thing as winter seeding. Certain plants can withstand the cold and then just come up when conditions are right in the spring. Advantages are an early crop and no need to start seedlings indoors. I will purposefully experiment more this year, but for now, pasta with fresh baby spinach and chives for lunch!