Garden Tips: Tomato terms for novice gardeners

My dreams of tasting homegrown tomatoes again next summer are giving me solace during this long dreary winter. Cabin fever has me perusing seed catalogs and deciding which varieties I want to grow.

If you are a novice gardener doing the same thing, you might wonder at some of the terms used to describe specific varieties.

▪ Heirloom: While there is no clear or official definition for heirloom, it is typically used to refer to an open-pollinated vegetable or flower variety that has been passed down from generation to generation within a family, ethnic, tribal or community group, and has been recognized as a variety for at least 50 years, or was commercially available before 1940.

In recent years, growing heirloom tomatoes has become a huge gardening trend because of the general opinion that heirlooms are much better tasting when compared with modern hybrids. However, heirlooms are not necessarily better when it comes to tomato production. Modern hybrids were developed to reliably produce fruit with a shorter growing season. Disease resistance, more compact vines and uniform fruit less prone to cracking were some of the other characteristics bred into modern hybrids.

▪ Open-pollinated: Heirloom vegetables are able to be handed down from generation to generation because they are open-pollinated. Open-pollinated varieties are plants that are self-pollinating, or have been kept isolated to prevent possible cross-pollination with other varieties, or both. Open-pollinated heirloom varieties are very similar from generation to generation, but not as uniformly identical as modern hybrids. If you want to save the seed of an heirloom tomato variety, take precautions to prevent possible cross-pollination when planting more than one tomato variety in the garden.

To prevent cross-pollination, plant varieties 20 to 25 feet or more apart. Also, plant taller or pollen-producing crops, such as pole beans, corn or squash, between the two varieties.

▪ Heirloom hybrids: Recently introduced by PanAmericanSeed, a major international seed company, are heirloom marriage hybrid tomatoes. These are hybrids created using different heirloom parents to produce hybrids that have been “bred for improved yield, earlier maturity and fewer blemishes while maintaining old-time flavor.”

▪ Grafted Tomatoes: Grafted tomatoes are plants where one variety (scion) has been grafted onto the stem and roots of another variety (rootstock). The scion is often a tasty heirloom variety that lacks disease resistance, and the rootstock is a hybrid variety that has been bred to be resistant to specific soil-borne diseases. Rootstocks may also impart increased plant vigor. Using grafted plants is valid if a specific rootstock is resistant to soil-borne diseases that are a problem in a particular area. If not, the extra expense of grafted plants is probably not warranted.

▪ Disease resistance: When researching tomato varieties in seed catalogs or check the tags on plants at a favorite nursery, the description of hybrid varieties may be followed with a code that indicates the resistance to specific diseases. These commonly include V for verticillium wilt; F for fusarium wilt; N for nematode; T or TMV for tobacco mosaic virus; TOMV for tomato mosaic virus; TSWV for tomato spotted wilt virus; EB or AB for early blight; LB for late blight; and SLS for septoria leaf spot. Resistance to verticillium wilt, fusarium wilt and nematodes, along with mosaic viruses, are the diseases that local gardeners should consider when buying tomato seed, plants or grafted plants.

This story was originally published February 5, 2017 at 1:39 AM with the headline "Garden Tips: Tomato terms for novice gardeners."