By the time the frost starts covering the lawn at the end of the season, many gardeners, like their lackluster plants, are spent.  The extreme heat of summer has drained every ounce of energy from them.  It is all too easy to ignore what waits outside.  But by accomplishing a few simple chores before those first flakes fly, you can ensure healthier and happier plants. 
Flowers
Many perennials become crowded and may benefit from being divided every 4-5 years.  As a general rule, perennials that bloom in the spring should be dug and divided in the fall.  Perennials that bloom in the fall should be dug and divided in the spring.  Dig perennials 3-4 weeks before the ground freezes. 
Trees
Trees' trunks can be damaged by winter sun from the south and west.  Protect young tree trunks by wrapping them with white tree wrap available at any local nursery or garden center.  The white wrap helps reflect the sun from the tender trunks.
Lawns
Late fall (late Oct. - early Nov.) is the best time of year to feed your lawn.  Apply a quick-release nitrogen fertilizer after the last mowing.  Even though the grass doesn't appear to be growing, energy is being shipped down to the root system for storage.  This stored energy will present itself in early greening next spring.
Did you know?
Fall is one of the best times to plant nursery stock.  Cooler weather makes the transition easier for the plants.  It also gives the plants a head start for next spring by producing root growth this season.
For more information on other outdoor activities to prepare for winter see the USU Fact sheet "Winding Down for Winter".