Is there any reason why tomato seeds can't be planted directly in the garden instead of starting them indoors? If they can be started outdoors would you want to plant them a little deeper? Just curious.

Indeterminate tomatoes produce until the end of the season. So people start indoors to get more tomatoes earlier. Also transplanting with the stem below the ground helps create a better root structure.

I like planting the plant laying down because the roots are closer to the surface which means they can breath better and the soil is MUCH warmer close the the surface. I don't have a hot summer, so keeping the roots warmer is a big deal to me.

You can't just plant them deeper. When the seed germinates and emerges, it only has so much energy to get to the sun. If planted too deep it will either by spindly and weak, or die trying to get to the surface.

Hope that helps.