A root vegetable, where the food portion of the plant develops underground (carrot, beet, potato, etc.), could represent:
- An activity where most of the action is unseen or unknown (as the part of the plant that we tend to see as food is developing unseen, underground)
- The act of methodically stashing something away (money, ideas, etc.), as a root vegetable "stashes away" nutrients and moisture in its root
- Something invested or planted (money in stocks, ideas in the subconscious mind, a problem situation, etc.) that grows or becomes bigger somehow, possibly without your awareness (since the root grows unseen underground)