On the backs of seed packets you will find a colorful map of the United States, with wavy bands of color. These are The Plant Hardiness Growing Zones, each zone is in a different color. We automatically consult these maps when we plan to plant our plants and seeds.
These Plant Hardiness Zones used to divide the United States and Canada into 11 hardiness zones based on a 10 degree Fahrenheit difference in the average annual minimum temperature. Because many areas have become warmer since 1990 when the last USDA hardiness zone map was published, the Arbor Day Foundation realized the need for a change in the defining zone lines because of the warming earth. In 2006, in request for up-to-date information, the Arbor Day Foundation developed new zones based on the most recent 15 years' data available from the National Oceanic and Atmospheric Administration's 5,000 National Climatic Data Center cooperative stations across the USA.
Significant portions of many states have become warmer since the 1990 USDA maps, some as much as one full hardiness zone. Much of Illinois, Indiana and Ohio have shifted one full zone, from a zone 5 to a zone 6. Some states have shifted two full zones. These hardiness zones are based on average annual low temperatures using 10 degree increments.
The Arbor Day Foundation is a nonprofit organization of nearly 1 million members. Its mission is to inspire people to plant, nurture and celebrate trees. The foundation believes tree planting is among the positive actions that people can take to reverse the warming trend.
In 2012, the USDA (United States Department of Agriculture) reviewed its hardiness map and found, that indeed, climate change had occurred and the zones had shifted. In January 2012, a message was sent down to the master gardeners with the new hardiness zone maps devised by the USDA. The new map, developed jointly with Oregon State University's PRISM Climate Group, is available online at www.planthardiness.ars.usda.gov. ARS is the chief intramural scientific research agency of USDA.
This new map was based on temperature data measured at weather stations for a longer and more recent time periods, 1976-2005, as compared to the 1990 maps of 1974 to 1986. It includes 13 zones, adding zone 12 and zone 13, with the inclusion of 5 degree Fahrenheit half-zones of A and B. Catherine Woteki, USDA under secretary for Research, Education and Economics, said, "This is the most sophisticated Plant Hardiness Zone Map yet for the United States. The increases in accuracy and detail that this map represents will be extremely useful for gardeners and researchers."
Each zone represents the average annual extreme minimum temperatures at a given location during a particular time period. They don't reflect the lowest it has ever been at a location, but the average lowest winter temperature over a specific time period. Users may bring up the map and type in their ZIP Code to find their hardiness zone. Gardeners and plant breeders are the largest users of the hardiness zones. The USDA Management Agency also uses it to set some crop insurance standards. Scientists use it as a data layer in research such as studying the spread of exotic weeds and insects. A poster-sized version will not be available to buy as in the past; anyone may download the map free of charge from the Internet and print copies for themselves.
Do be aware that Plant Hardiness Zones are a general guide. There are many other factors to consider-soil types, rainfall, daytime temperatures, day length, wind, humidity and heat. Micro climates exist within your own yard. You determine what will and what won't work in your garden. Florida has four growing zones-North Florida, Central Florida, South Florida and Tropical Florida - zones 8a to 11b. We are in zone 10a and inland, 9b.
Time zones are another "thing." Tonight we set our clocks ahead, spring forward. Daylight Saving Time is upon us. We lose an hour. At first, time was kept by sundials based on the position of the sun, later, mechanical clocks were invented, and now we have complicated them with Daylight Saving Time.
Daylight Saving Time was first conceived by Benjamin Franklin, but wasn't seriously thought about until 1907 in England. Germany joined England with the idea of conserving energy during World War I. They enacted laws in 1925. The United States adopted forms of it in 1919, and then Franklin Roosevelt instituted it during World War II from 1942 to 1945. States were later allowed to do their own thing after President Nixon signed it into law in 1974. Arizona, Hawaii, and the territories of Puerto Rico and the Virgin Islands still have not changed; and I lived in Indiana when they voted not to change ... which lasted until 2005. The Energy Policy Act of 2005 decreed that DST starts at 2 a.m. on the second Sunday of March and ends at 2 a.m. on the first Sunday of November. Savings time seems to be a misnomer to some people, who can't see that we have less or more of the hours. They insist it is just Daylight Shifting Time. Fire departments suggest we change the batteries of our smoke alarms when we change our clocks.
I read a story where a wise Indian chief says, only in America would someone think that cutting off the top of a blanket and sewing it onto the bottom makes the blanket longer Now that is zoned out!
But, you can still thank a tree for our ozone and devouring carbon dioxide.
Joyce Comingore is a master gardener, on the board of directors of the American Hibiscus Society, FFGC District IX Tree Chairman and a member of Garden Club of Cape Coral.