A Swede grows below ground.
They grow above ground. It is a stem plant.
Above the ground
above.
Below ground, just like a carrot.
Above ground. It is a flower.
Cabbage grows above ground.
Both
Below ground.
Above ground as the oat plant is like wheat.
No corn grows on a corn stalk above ground.
The potato tubers (potatoes) grow below the ground, but most of the potato plant (leaves etc.) grows above ground.
Dates (Phoenix dactylifera) are the fruits of the Date Palm trees, and are above ground.