Map out a successful garden using Mother Nature as a guide

August 18, 2005
KAREN HERMES RENGER
Victoria County Master Gardener

Perhaps the most important consideration in determining what plants you can grow in your garden is whether or not they will survive the climate in our area.

There are two maps that are useful in determining plant hardiness. The U.S. Department of Agriculture (USDA) Plant Hardiness Map is a drawing that starts with zone 1 where minimum temperatures can go down to minus 50 degrees Fahrenheit, and ranges to zone 11 for gardeners in Hawaii and extreme Southern Florida where lows don't drop below 40 degrees Fahrenheit. This map is an accumulation of information over a period of 60 years, and the zone ratings were intended to indicate adaptability of plants based on climatic conditions.

Another map, Gardening Regions for Texas, factors in average winter minimum temperatures in Texas to further determine plant hardiness. Your zone determines the difference between a certain plant being sold as a perennial (will come back year after year) or an annual (only lasts a year) in your zone.

Victoria area gardeners are in zone 4 of the gardening regions for Texas and zone 9 on the USDA Plant Hardiness Map. Both of these maps accompany this article with noted average minimum temperature ranges for the respective zones. All of this information can be located on the Texas A&M Horticulture Web site, http://aggie-horticulture.tamu.edu/plantanswers/fallgarden/zones.html You can also access related information at http://aggie-horticulture.tamu.edu, clicking on "wildflowers" and then "growing information." The term "hardiness" refers to a plant's ability to survive outdoors year-round without protection.

How can you determine if a plant is hardy? First, buy from a local nursery or garden center where most all of the plants are hardy, unless they are annuals or tropicals. It is necessary to consult the informational tag attached for details on care and light requirements, planting and watering instructions and in what zones the plant is considered hardy. These tags are accurate and should be followed.

When using the map to select a suitable plant, gardeners should keep in mind stress factors - like too much water, not enough water, sun, shade, pollution or wind - that can reduce plant hardiness. In addition, there are many new techniques of watering, planting, fertilizing and controlling pests that may increase a plant's growth, but also reduce plant hardiness.

It is very important to remember that the elements in nature are highly variable, and maps should be considered generalizations. For example, in many cases you can grow plants that are rated hardy one zone south of yours if you protect them during the winter. Plants that are not hardy in your area may also be grown in containers or in a protected area in your landscape. In addition, the landscape industry has worked with plant breeders to introduce many new forms of traditional plants that will adapt to a wider range of environments. Some outdoor tropical plants thrive in the heat, but they don't tolerate freezing temperatures. I have adapted my own garden in Hallettsville with some tropicals like angel's trumpet, ixora, allamanda, bird of paradise, jatropha and mandevilla, to name a few.

It's always good to remember to look for plants labeled with the Texas Superstar logo. According to "Best of Texas" landscape guide, Texas Superstar is a cooperative program in which university and industry leaders partner in the identification of superior vegetable and landscape plants for Texas. Recommendation of a plant as a Texas Superstar means that the variety has been subjected to statewide testing and has been found to be adapted to all growing areas in Texas. These plants are easy to care for, hardy and are disease and insect resistant. Some of my personal favorites are esperanza, fire bush, flare hibiscus, Moy grande hibiscus, Belinda's dream rose, knock out rose, VIP petunia, burgundy sun coleus, Laura Bush petunia, zinnia, butterfly weed and the 444 tomato. Visit the Texas Superstar Web site at http://www.texassuperstar.com/ for more information.

In addition to learning about plant hardiness from the USDA Plant Hardiness Web site, I found great information on wildflowers. Planting dates largely depend on weather patterns. The planting timetable should be decided by seasonal precipitation rather than temperature. Wildflowers can be planted in spring, which is recommended in mild climates or fall throughout all regions in the United States. However, in zones 7-11, the months of September-December is a more favorable time.

Wildflowers must germinate in late summer or early fall to develop good root systems and be ready to grow in spring when the weather warms up. For an overview of wildflower planting, go to http://aggie-horticulture.tamu.edu/wildseed/growing/hardinesszone.html. Some great Texas wildflower mixes are corn poppy, cornflower, lemon mint, phlox, black-eyed Susan, Indian blanket, coreopsis and the Texas bluebonnet. For best results always follow instructions on back of the package. If you have no directions, generally you should loosen the soil and mix the seeds with some sand and broadcast. Water when necessary and enjoy Texas wildflowers in your own landscape.

When my children were young, they resisted gardening because most of the time they associated it with, what they called, "ahhhh, pickin' weeds?!" It has been a joy to see my now adult children show an interest in not only my gardening, but also, their own. I recently read in the "Texas Home Gardening Guide" about the increasing popularity of gardening, and it is estimated that one in every three families does some type of home gardening. Remember the old master gardening rule and prepare your beds adequately. When you are ready to make your plant selections, read the tag, do your homework, and don't forget to consult a well-versed gardening friend for advice about his or her successes and failures.