OCD Gardener
That one person at the end of your block, usually retired, who spends anywhere from 20 to 9000 hours a week gardening. Symptoms include crying over your begonias, mowing the lawn 20 hours a week and sneering at the potted plant garden in your office.
Mr. Jenkins is an OCD Gardener. I swear that's the fifth time today he's been out today to fertilize his ginko trees.