Some gardeners know what characteristics they prefer in a tomato, so they grow the same variety every year. Others browse through garden centers or seed catalogs and adventurously select new varieties. If you are the latter, you first must choose between hybrids or heirlooms.
Heirloom tomato plants generally produce tastier fruit, but they're prone to disease and thus require more maintenance. Heirlooms breed true, which means the same characteristics are passed on from generation to generation. You can save the seeds from your heirloom Brandywine tomato each year without having to buy new seeds. Each time you plant those seeds, you will get a Brandywine tomato. Nearly all heirloom tomato cultivars have an indeterminate habit of growth, which means they continue to grow during the season and fruit production is spread over a longer time. Growing heirloom varieties helps preserve the genetic diversity of plants and contributes to the overall health and biodiversity of our planet.
Hybrid tomato varieties result from the crossing of two genetically distinct parents. Commercially hybridized seeds are created to breed desired traits such as flavor, texture, pH, size, days to harvest or disease resistance. Hybrid tomatoes can be indeterminate or determinate. Fruit production on determinate plants yields a concentrated harvest in a small window of time. This is ideal for those who plan to preserve sauce or juice. Determinate varieties are ideal for patio containers.
First-generation hybridized plant crosses grow better and produce higher yields. These seeds are genetically unstable, though, meaning the offspring will not have the same characteristics as the parents. For example, if a gardener saves seeds from the hybrid "Early Girl," the next season that seed would result in very few plants resembling the hybrid "Early Girl." Hybrid seeds must be purchased annually to replicate the hybrid variety.
When growing tomatoes the first time, read the labels or catalog descriptions to choose the varieties that produce the results most important to you.
Colorado State University Extension has research-based answers to your horticulture questions at ask.extension.org.