If you live around cities such as San Juan, Puerto Rico (18°N); Cartagena, Columbia (10°N); Belém, Brazil (1°S); Kingston, Jamaica (18°N); Jakarta, Indonesia (6°S); Kuala Lumpur, Malaysia (3°N); Lagos, Nigeria (6°N); Mumbai (Bombay), India (19°N); or Mogadishu, Somalia (2°N), your plant hardiness zone is 13. This means average annual minimum temperatures are between 70°F and 60°F (21.1° to 15.6° C).
USDA plant hardiness zone 13 straddles the equator in the interior of continents (e.g. Zaire in Africa, Brazil in South America), stretching farther north where oceans and warm enclosed seas (e.g. Caribbean and Red Seas) increase their influence.
It is best known as the biologically diverse zone of the tropical rainforest; and where you find edible plants such as the banana and pineapple, spice trees such as peppercorn and cinnamon, and colorful flowers such as orchids and titan arums.
What Are Hardiness Zones?
We define hardiness zones as geographic regions, most commonly based on USDA criteria that support specific plants, flowers, and trees. They usually define a minimum range of temperature that a plant or tree can survive safely in that zone and range from the harshest zone one to tropical zone 13.
If possible it is advisable to consult other planting-related maps such as first and last frost dates, and heat zones.
Zone 13 Regions in the United States
In the United States, the temperature range restricts Zone 13 to Puerto Rico (e.g. San Juan) and isolated parts of Hawaii. Nevertheless, it is important for residents from other zones to know about cold-sensitive tropical ornamental plants; in particular, when to bring them indoors.
The export of ornamental plants is a growing industry in Puerto Rico along with the associated threat of pests.
With modern Geographic Information Systems (GIS) which allows for higher resolution, smaller areas of zone delineations are possible. Thus, we can identify isolated parts of the zone along parts of the big island of Hawaii’s central-western coastline.
Significant Zone 13 Regions in South East Asia
This extremely bio-diverse rainforest area is home to shrubs such as the jambu or watery rose apple (genus: Syzygium, and species: aqueum), a small, crisp and mildly sweet, watery fruit.
The zone stretches from southern India and Sri Lanka through to Indonesia and Borneo.
Surrounded by oceans and characterized by seasonal monsoons, the resultant climate is hot and humid. By way of example, Singapore receives 2282 mm of precipitation annually.
Zone 13 Regions in Africa and South America
Rainforests cover large sections of northern South America and central Africa. It’s worth noting, however, that while we think of rainforests as being rainy, in reality, compared to other rainforests throughout the world, Africa’s are drier by several hundred millimeters per year.
In Africa, the countries that have rainforests are Cameroon, Congo, Democratic Republic of Congo, Gabon, Ghana, Ivory Coast, Liberia, and Nigeria.
In the rainforest areas of Central America (e.g. Costa Rica), South America (e.g. Amazon) and along the Andes Mountains (e.g. Peru), we find the largest family of plants in the world, the orchids.
Plant Advice for Gardeners
When purchasing tropical plants such as azalea, bamboo, hibiscus, orchids, and poinsettias, be aware of related diseases. These can include many types of bacteria and fungi. Also be aware of associated beetles and weevils, in addition to moths and caterpillars found not only on the plant, but also in the soil.
In addition, always ask for a Phytosanitary Certificate undertaken by a National Plant Protection Organization (NPPO), a declaration attesting to freedom from regulated plant pests.
North American Gardeners and Zone 13 Plants
Even though Zone 13 exists in only a sliver of North America, gardeners throughout the continent benefit from knowing the needs of their Zone 13 tropical plants.