1″ x 3/4″, found objects

It’s springtime and we’ve pulled out the tools for the garden.  For the most part they get used and then stuck in the dirt until the next time we need them, which means that every day as I walk to the door I pass a spade sticking out of the soil. That gives many reasons to think about all the spade-related expressions that I don’t fully understand.  My mom used to say “better call a spade a spade”.  I know there’s a card reference, but what’s the connection?  And why would something you have a lot of be something you have “in spades”? I know I could just google the answers, but instead I’ll wonder for a while longer, passing the spade in the garden each day.