It is regrettable

"My son, it is regrettable that you can't be here to plant the tomato garden with me this year. The soil is too hard for me to dig myself. I look forward to the day you come home so we can continue this tradition together."

The son writes back, "Father, don't dig up the tomato garden, that's where the bodies are buried."

That night around 2 AM, the police show up at the old man's house with a warrant to search the ground for bodies. After several hours of digging around, they find nothing, apologize to the man, and go on their way.

The next day, the man receives another letter from his son, "Father, given the circumstances, this was the best I could do. You should be able to plant the tomatoes now."