Tomato Varieties in USDA Zones

Cool Hardiness Zones

• Hardiness zones are more meaningful for perennial plants, such as asparagus, rosemary and echinacea, than they are for annual plants, like tomatoes, spinach and cosmos. The reason is due to the necessity for perennial plants to survive through cold winters. Annual plants die back every year, regardless of temperature. Gardeners in northern hardiness zones should choose annuals that are able to withstand cool temperatures, in the event of spring temperature dips and early fall frosts. Cold climate gardeners choose early season tomato varieties, such as Early Girl, Quick Pick and Subarctic Plenty. These cultivars are able to withstand cool temperatures and yield fruit within 45 to 60 days.

Hot and Humid Climates

• The Southeastern United States has zones 5b through 10b. Temperature lows dip between 10 degrees below zero to a balmy 35 degrees. The variances are due largely to topography rather than physical location. Higher altitudes are colder while lower altitudes are warmer. Areas closer to large bodies of water are warmer as are urban areas. Avoid planting tomatoes in heat-prone areas, such as near the sides of buildings or blacktop. Hardiness zones do not take humidity into account. When choosing a tomato cultivar, gardeners must be aware of the potential for mold, mildew and wilting. Such conditions affect tomatoes planted in very humid areas. Choose cultivars that are disease-resistant. Plants with cultivar names followed by the acronyms VF, VFN and VFNT are resistant to verticillium, fusarium, nemotodes and tobacco mosaic diseases.

Hot and Dry Climates

• The Southwestern United States is also home to hardiness zones 5b through 10b. Though the Southwest does not experience the humid conditions found in the Southeast, the same types of cultivars are grown in both regions. Heat-tolerant cultivars, such as Heatwave and Celebrity, produce medium-sized tomatoes. The cold-tolerant, medium-sized Early Girl tomato also tolerates heat and is found growing in southern gardens. Plum and cherry varieties, like Yellow Pear, Sweet 100 and Porter, are also found in warm climates. Paste tomatoes, including Roma and Viva Italia, can be grown in desert climates.

Considerations

• In dry conditions gardeners place mulch at the base of the plant beds. Ensure that the mulch is piled loosely and does not come into direct contact with the plant's base. This prevents the possibility of mold and disease. In humid climates mulch is not necessary. Regardless of climate or hardiness zone, tomatoes are heavy feeders. Choose slow-release fertilizers and keep plants well watered. Slow-release fertilizers help regulate the amount of nutrients that plants receive. Too much nitrogen too early in the growing season results in a poor crop.