Planting too deep?

[momotaro]

Hi - I'm in the Bay Area (zone 9b) where soil temps are ~65-70 degrees F.
I know the general rule is to plant tomatoes as deep as possible to grow roots along the stem; however, in my raised bed that's about 1 foot deep on top of the ground, it feels *much* cooler down about a foot, close to ground level. I haven't measured it but am guessing it's 60. My planter box is in indirect sun (maybe it will be more direct in July).

Is that OK or should I just lay them sideways? Thanks!