Tomatoes are prone to diseases such as crown rot and mosaic virus, as well as problems with insects. Some problems are based on poor nutrition to the plant; some by poor gardening practices. Hornworms and flea beetles are common insects on tomatoes. Many problems can be alleviated through the organic gardening method of adding nutrient rich humus (compost) to the soil before you plant tomatoes. Some tomato seeds are hybridized to resist common disease problems.
Heirloom varieties of tomatoes have not been cross-pollinated and are the result of the "survival of the fittest" seeds. Traditionally, families or localities save the seeds of the most flavorful and hardiest tomatoes.
'Brandywine' heirloom tomatoes are said to come from an Amish valley of that name. There are purplish-maroon and pink varieties of 'Brandywines'. When insect or wilt problems develop, they can be controlled with herbal insecticides. Incorporating compost into the soil at planting time also creates a more disease resistant tomato plant.
The variety known as 'Anna Russian' is a tomato that has the natural disease resistant characteristics of heirlooms. It is a very large (up to one pound) pink, heart-shaped tomato that grows on indeterminate vines. Indeterminate tomato vines continue to grow throughout the summer season, stopping only at frost. The vines can range from 8 to 12 feet and are best supported on stakes or tomato cages.
Allow at least 2 feet between plants when they are allowed to sprawl on the ground. The 'Anna Russian' has juicy flesh and good flavor and is ready to harvest in only 68 days.
'Quick Pick' is an early tomato that is bred for resistance to the most common tomato diseases such as fusarium wilt, nematodes, verticillium, mosaic virus and blight. It ripens in 60 days and is a good choice for northern gardens that have a shorter growing season. The tomatoes grow to a weight of only 4 ounces, but 'Quick Pick' is a heavy yielding plant. Hybrid tomatoes such as this one come to harvest all at the same time.
The 'Floramerica' tomato is referred to as a "main crop red" because it is harvested in the middle of the growing season. It is bred for resistance to fusarium wilt and verticillium disease. It is important to practice good sanitation habits in tomato cultivation as a disease preventative, even when you grow hybrids that are bred for disease resistance. Clean up all fallen fruit promptly.
Yellow and orange tomatoes also are grown in hybrid disease resistant and heirloom varieties. Among the heirlooms, 'Yellow Pear' is a small variety that dates to 1870. The skin and flesh are yellow and fruit is 2 inches long. It is ready to harvest in 10 weeks, and grows on long, indeterminate vines.
Another yellow tomato is the 'Mountain Gold'. It is a hybrid that is bred for resistance to verticillium and Fusarium wilt diseases. Pick off hornworms each night or morning. Baking soda or hydrogen peroxide sprays are effective antifungals for heirloom tomatoes.