South Florida, including the Keys, lies in Zones 10 and 11, which is considered the subtropics. You can plant trees and shrubs any time of year, although midwinter may not be ideal because new plantings will need daily watering.
Most homeowners start a lawn with sod.
Chinch bugs are our worst lawn problem. The tiny insects suck sap from grass stems. It once was customary to spray a lawn several times a year with insecticide, but experts now advise spraying only when and where bug damage appears. Mow high, no shorter than 3 inches for St. Augustine. Our soil is sandy and alkaline.