Written by: Claudia Zweber

No matter how you say it, the Master Gardeners of Dakota County will have them at our Spring Plant Sale on Saturday, May 13.  “Tomato-ganza” is back by popular demand!  Over 35 varieties have been planted at our greenhouse (2017 Varieties).  Note:  Due to growing conditions, not all varieties may be available at the sale.

With so many choices, how do you pick the perfect varieties for your garden?  A review of these “tomato terms” may help you decide:

• Heirloom vs Hybrid
• Determinate vs Indeterminate
• Size
• Season

Heirloom vs Hybrid

To start a lively discussion, say these two words around tomato gardeners.  There are those that are in favor of one or the other and those that like both.

A hybrid vegetable is created when different varieties are cross-pollinated by humans to produce an offspring (hybrid) containing the specific traits of the parent plants.  (Hybrids are not GMOs (genetically modified organisms), which involve mixing genes from different species.)

An heirloom vegetable is one that’s been around at least 50 years and is open pollinated. Open pollinated means pollination is by insects or wind without human intervention.  If there is not cross pollination, seeds saved from heirloom plants will produce the same plant as the parent.  Heirlooms are often called “pass along” plants because there is a story passed along with the seeds.  For example, in 1940s Logan, West Virginia, a radiator repairman crossed four of the biggest tomatoes he could find to produce “Mortgage Lifter”, a classic heirloom tomato. He sold seedlings of it, using the proceeds to pay off his $6,000 mortgage in six years.

In general, the advantages of hybrids include adaptability to a wider range of growing conditions, dependability, lower care, early maturity, better yield, specific plant size, and disease resistance.  A disadvantage is that seeds cannot be harvested and saved for subsequent years because hybrid seeds will revert back to the parent plants.

While hybrid plants typically yield a crop that is uniform in both appearance and timing, heirloom vegetables produce a “mixed bag” harvest. The harvest may come in less predictably, and fruit size can vary greatly even on the same plant.  However, hybrids can’t match the range of colored fruit available from heirloom plants.  And, by harvesting seeds from heirloom plants, you can help preserve our heritage.

Many gardeners contend that most heirloom varieties boast greater flavor than hybrids.  While this may be true of early hybrid varieties which were developed to boost the yields and distribution capabilities of commercial growers, hybridizers have recently been focusing on flavor.  For example, Juliet, a 1999 All America Selections winner offers great taste and productivity along with improved disease resistance.

Determinate vs Indeterminate

The growth habits of tomatoes are classified as determinate or indeterminate.  Determinate varieties grow to a compact height (generally 3 – 4 feet), then stop and set one large flush of fruit over 1 – 2 weeks.  In other words, there is one harvest with these varieties.  Determinate varieties are sometimes called bush tomatoes.  Dwarf or small bush determinate varieties are good choices for containers and gardens with limited space.

Determinate varieties are also good for preserving since all the fruit is available at the same time. Indeterminate grow all season long and produce fruit until frost. The long vines of indeterminate plants require sturdy support.  Some gardeners will prune these varieties to encourage fruit production over foliage growth.  Most heirloom varieties are indeterminate.

Still other varieties of tomatoes fall somewhere between these two growth habits, and are called semi-determinate. They will grow larger than determinate varieties, but are not as rampant as indeterminate ones.  They typically grow 3 to 5 feet tall. They should be staked, but are less likely to outgrow their stakes than indeterminate types. They will produce a main crop that ripens together, but will also continue to produce up until frost.

Size

• Cherry and grape tomatoes are bite-sized for snacking and a staple of summer salads.
• Paste tomatoes are used for sauces, catsup, tomato paste, and canning.
• Slicers are larger than grape, cherry, and paste tomatoes. Some can weigh in excess of 2 pounds.  They are often sliced and used in sandwiches.
• Beefsteaks are large tomatoes, usually over one pound with some up to two pounds. They are typically wide, but the more round types have greater flavor.  Due to their size, they have the greatest days to maturity.

Season

Tomatoes are generally classified as early, mid, or late season.  Days to maturity (DTM) determines a variety’s season.  DTM is the number of days from transplanting the seedlings into garden until the first appearance of mature fruit.

Since our tomato plants will come directly from our greenhouse, you will need to “harden” them off for 7-10 days prior to planting them in the ground.  “Hardening off” is the process of acclimatizing plants to outdoor conditions, especially direct sunlight. Ten days of hardening off brings us close to Memorial Day weekend, which is the old wives tale of when tomatoes should be planted.

Looking at a variety’s season will give you a rough estimate of when you can expect to be harvesting that tomato from your garden:

Still can’t decide?  Master Gardeners will be available at the sale on Saturday, May 13^th, to answer your tomato and other gardening questions.