On Friday I did a presentation and workshop at college for some Culinary Students & Instructors. There was no school for the kid and she thought it would be cool to check out the college. I had left my daughter with the group sowing tomatoes to have a look at the garden. One of the students asked her if the plant will still grow if the seed is too deep. Her answer was way better than what I would have said:
Melissa's advice on sowing too deep: "The seed has only so much energy packed in there. If the seed is too deep, it may run out of energy trying to make it to the surface where it will be able to start producing it's own energy, which it gets from the sun."
As Melissa advises, it is best to plant not too deep. This is from a 13 year old. Guess she pays attention to my babbling when we are sowing seeds.
joanna b, I pay close attention to the depth my tomato and pepper seeds are planted, and some come up earlier than others. I usually consider the earlier seedlings to be the hardiest or most viable and transplant only the larger seedlings with the largest root system. It is difficult for most people to only select a few seeds to transplant, but I am convinced the larger the seedling and root system, the better the crop. About two or three out of ten seeds planted ever make it to my garden. I do something similar with lettuce and cole crops, planting four or more seeds to a hole and saving only one seedling. To some that would seem like a waste of seed, but seed cost is not something I would scrimp on. Even in the garden when I am direct seeding corn or beans I replant wherever a seed has not sprouted with the others. I space corn fourteen inches apart in a row and beans ten inches using a measured stick to I know exactly where a seed was planted. Plant vigor has much to do with crop production in my opinion and Melissa's sage advice makes good since to me as well.