What is the irony of A Summer Tragedy by Arna Bontemps?

Jeff Patton and his wife have suffered a series of tragedies, and both have physical disabilities that prevent them from continuing work on the farm, particularly Jeff. As they drive to their destination, Jeff, the hapless sharecropper, suddenly feels excitement and a renewed sense of purpose.
The couple are on their way to commit suicide, so the irony of the story is that Jeff has found purpose in his life again whilst driving towards his death. The blooming crops is also symbolic of the ups and downs in life.
There is a season when things die, yet they "resurrect" the following season. However, Jeff and his wife have made a final decision regarding their fate. Another example of irony, although subtle, is the fact that Jeff wore a suit that he rarely used. It wasn't until the day of his demise that he wore something nice; perhaps symbolic of his lifelong despair as a poor farmer finally ending with him dressed as a rich man.