A wife wrote a letter to her husband in prison: "I would like to plant some lettuce in the back garden. When  would be the best time to plant them?"

The prisoner, aware that the prison guards read all mail, wrote a letter back: "Dear Wife, Do NOT touch the back garden, whatever you do.  That is where I have all the gold hidden."

A week later, the prisoner received another letter from his wife: "You are not going to believe this. Some men came to the house with shovels and dug up the entire back yard."

The prisoner then wrote his wife again: "Dear, NOW is the best time to plant the lettuce!"