In 1965 the US Department of Agriculture created what is referred to today as the Zone Hardiness Map. This map divides the United States into separate zones each defined by being an average winter temperature that is ten degrees (Fahrenheit) different (warmer or colder) than the adjacent zone. This guide was designed to help people to determine which plants would grow best in the areas in which they live. Originally this map included only ten separate zones however a revision was made in 1990 to include a new zone; Zone 11, to account for the very warmest climates found in the US.
Zone 11 is defined as having an average winter temperature of no less than 40 degrees and as such is typical only to the climate found in the US in Hawaii and the lower part of the Florida Keys. With no real annual frost coverage these tropical areas are perfect for year round growing and are ideal for tropical plants.
Planting options for Zone 11 are abundant and include ferns such as the Mother Fern and Australian Sword Fern, trees such as palm, citrus, oak and olive varieties along with innumerable flowering plants like the Kaffir, Peruvian and African Lilies, ground orchids such as Bletilla striata and Spathoglottis plicata and many, many other varieties such as hibiscus, morning glory, leucadendron and nasturtiums.
Of course Zone 11 is also excellent for growing many types of fruits and vegetables such as guava, papaya, citrus, melons, peppers, squash and even herbs and spices such as mustard, parsley, lemon grass, rosemary and basil.
Despite the year round growing season, there are still some guidelines that you should follow to insure that you receive the greatest return from your planting efforts.
~ Different plants thrive with differing levels of sunlight. Always check the guidelines for the specific plant to insure that it has the proper placement in your yard for the light levels that it requires.
~ Be sure to place plants that require a lot of sun in areas of your yard that will see at least six hours of sunshine per day.
~ Planting herbs and vegetables on level ground with proper spacing between rows helps to insure that there is good irrigation and drainage as well as providing plenty of room for sunlight to reach each plant.
~ When planting your garden, always use the freshest seeds possible as older seeds may fail to germinate properly.
Not surprisingly, one of the easiest ways to determine what plants are best suited to your climate is to consult the people at your local gardening center as they are fairly certain to not only know what varieties of plants thrive in your region but will also likely have several specimens available for purchase on site. You may also want to look into local gardening clubs as these can provide a wealth of information on local growing conditions as well as providing opportunities to meet people in your area with similar interests in gardening.
You can find out more about growing conditions in Zone 11 by consulting the United States National Arboretum on the web at www.usna.usda.gov/Hardzone/ushzmap.html or from the National Gardening Association at www.garden.org/zipzone/ .