And, the other side of the coin:
I have had good luck planting tomatoes deep. I have used the deep method in both coastal SoCal, and Puget Sound areas.
I transplant to the point that the first (true) leaf is just above the surface.
The entire buried stem will begin sprouting roots. These 'extra' roots become mostly lateral, surface roots, while the original
root system goes deep. This gives the plant a deeper root system, as well as better surface roots. This has seemed to make them better scavengers for scarce
water.
I guess 'it depends' on your circumstances. If your subsoil is too cool, perhaps it will slow early growth.
If water is a problem, perhaps the better root structure would make up for it.
Next season, I hope to be in an area with a shorter season (but warmer summer). Perhaps I
should try
both and see which way works best in the new region.
A larger root system generally means a healthier plant, but I am not so certain that this is so important in an annual plant. With a
perennial, you really want the plant to spend its first year developing strong roots. When the goal is annual
fruits, you want the plant to quickly get into the 'reproductive' cycle, rather than devoting too much time to make itself 'permanent'.