Tomato Terminology

Tomatoes are the most popular home garden vegetable grown in America. We answer many questions each summer about tomatoes. There are literally hundreds of varieties of tomatoes available, making it difficult to choose which one to grow. Adding to that confusion are various symbols and terms describing the plants. Let me try to simplify several of these tomato terms.

Hybrid. Just like the name implies, a hybrid is a mix of different tomatoes. Plant breeders cross-pollinate plants, resulting in seeds that produce plants with some desirable trait. They are bred for disease resistance, color, taste, skin quality, shipping ease, and so on. Intentional breeding produces cultivars, while accidental crossings produce varieties. The terms are commonly used interchangeably.

Heirloom. More and more heirloom tomatoes are available each year. These are varieties that have been passed down through the years by saving seeds from fruits of non-hybrid varieties. Since tomatoes normally do not cross-pollinate, their seeds produce plants almost identical to the parent plant. These rarely have disease resistance, but do offer weird and tasty types. These are also known as open-pollinated plants.

Grafted Tomatoes. In recent years, an age-old technique called grafting has been used to create stronger, more productive, disease-resistant plants. Grafting involved blending two plants together physically, not through pollination and genetics. One plant becomes the roots (rootstock), while the other becomes the top (scion). Be sure you know if you have a grafted tomato plant because the graft union must remain above soil level in order to work.

Label Abbreviations. Tomato labels often have various abbreviations on them. These designate that the variety has some disease resistance trait: A for alternaria disease resistance, F-fusarium, N-nematodes, T-tobacco mosaic virus, and V-verticillum. This does not mean they are immune to the disease, but rather that they are less likely to get that disease.

Indeterminate or Determinate. These are the two types of tomatoes grown. Determinate tomatoes set fruit at the ends of their branches on terminal buds. Once buds are set they stop growing in height, so these plants need little or no staking and generally have a short harvest period. Indeterminate plants keep growing, setting fruit on lateral buds along the stem. These can grow quite tall, are usually staked, and keep producing fruit throughout the growing season.

Consider trying a new tomato variety this summer.