It is quite satisfying to tidy the garden by cutting back perennials that have finished blooming. It immediately makes the garden look more attractive. In some ways it is similar to de-cluttering a room in the house.
Deadheading, where one snips off the dead bloom, and cutting back where one takes off the entire stalk that has bloomed are both far more satisfying for me than housework. All one needs for these garden chores is a sharp pair of clippers.
There are all of the benefits of being outdoors, such as fresh air, birdsong, a peaceful environment and an escape from more stressful or arduous activities. The repetitive nature of the task of cutting back plants allows me to relax. Yet the related decisions, such as how far down the stalk to cut or whether to dispose of each stalk as it is cut or to wait to gather them all up later, provide enough of a challenge to keep me engaged.
One can devote as much time as one pleases to such tasks, too. For there is satisfaction to be gained whether one, ten or twenty plants have been smartened up by the gardener wielding shears; it is satisfying to admire one's handiwork and feel proud, no matter how long or short the time frame.
Few other tasks in my life provide me with so much reinforcement for such minimal effort.