Here in Florida we do not encounter the dramatic changes in foliage seen in cooler northern climates. To be sure we do experience the changing of the leaves just as other areas do, just not to the visual extreme evident in some locales. Autumn is, like all the seasons, a time of change. Cooling temperatures slow the above ground growth of leaves and other foliage, some will change colors and die off. Moister soil allows stronger development of roots. We can protect plants' overall health during this time by removing withered parts like spent stems and dead branches.
This is the perfect season to aerate the lawn. Compressed soil must be aerated so water and nutrients can reach the roots. On a small yard A garden fork can do the job. Bigger lawns may require a walk-behind aerator. It is also a good time to feed your grass. For most types of grass the roots keep growing until the ground gets down to around 40 degrees. Apply a high-phosphorus (12-25-12) mix to lawns in fall to encourage further root growth. This will also be beneficial after winter as your turf will green up earlier in spring.
During the cooler months your grass will grow much more slowly. This is a great time for an end-of-season mowing as disease has a harder time getting established with shorter grass. Also keep in mind that fallen leaves blow easier across the lawn with shorter grass because they have nothing to latch on to. Those leaves will also be a valuable addition to your compost heap. You will need to flip the leaf pile every week with a garden fork to aerate it. The resulting mulch can be used next year to nourish shrub borders, lawns, flower beds, and herb gardens.
This can be a good time of year to plant new shrubs which tend to be more cold-resistant. Planting them now gives the plants a head start at establishing roots in the season's cool, moist soil. At the same time you initiate new growth it is good to eliminate the remains of the old. Trimming branches and dead limbs can remove the possibility of them blowing down in cold windy weather and damaging your home or endangering your family. You can probably handle the small ones yourself but for the bigger jobs it is better to call in the pros.
The groundwork you do this season will prepare your lawn and landscaping for the next. Your autumn efforts will generate spring rewards. The work you do now results in healthier spring beds. Get rid of tired annuals, as well as the snails and slugs that feed on them, which breed in fall. Trim spent perennial foliage down to the ground and divide crowded tuberous plants, like daylilies and irises. The more space you create the more room you will have for flowers next year.