HOW DO YOUR TOMATOES GROW

By: Maggie L. Moor-Orth

Delaware Cooperative Extension

Delaware State University

Every spring I get many calls about what variety of tomato to grow in backyard

gardens. So, I thought before tomato gardening season begins and/or we order tomato

seeds, I would write an article to provide you with information to consider when selecting

tomatores for your garden.

First of all, you have to consider how much space you have, and if you had any

previous disease problems growing tomatoes. Most tomatoes should be spaced about 2

1/2 to 3 feet apart. Varieties have either an indeterminate or determinant growing habit.

Indeterminate tomato (INDT) varieties have a vine or climbing type of plant growth.

Indeterminate types also continue to grow from their stem tips and ripen or mature over

a longer time period. This is good if you want to have tomatoes until frost and/or want to

have green tomatoes at the end of the growing season. These definitely need to be grown

with a support structure: in a cage, on a trellis, or staked.

Determinant tomato (DT) varieties have a bushy-type of plant growth. They also

ripen or mature within a specific time period. Some folks don’t think determinant

tomatoes need to be supported, but I do. I like to keep my fruit off of the soil surface

which tends to cause fungal disease on the fruit. There are also varieties, like Patio and

Pixie, that are considered a dwarf type of determinant and are ideal for container

growing.

Another item to be aware of when selecting tomato varieties are initials and

numbers that follow the names of some varieties, for example: Celebrity F1, Viva Italia

VFFNA, Early Girl VW, or Super Sweet 100 FRI, TMV, VW. The following chart

explains the initials and what disease/pest they represent.

ASC	Alternaria Stem Canker
BLS	Bacterial Leaf Spot
BS	Bacterial Speck
BW	Bacterial Wilt
EB	Early Blight
Ff	Leaf Mold
FR1 or 2	Fusarium Race 1 or 2
GLS	Gray Leaf Spot
N	Nematodes
ON	Powdery Mildew
PVY	Potato Virus Y
TMV	Tobacco Mosaic Virus
SW	Spotted Milt
SBW	Southern Bacterial Wilt
VW	Verticilium Wilt

You may ask why it’s important to select a variety that may be resistant to a

disease or pest. We only get one chance to grow tomatoes to use in our family meals

during Delaware’s growing season and most of these diseases can destroy the plant

and/or render most of the fruit inedible. In most cases, the plant will not recover.

Therefore, if in the previous growing season your tomato plants had problems with a

specific disease, then you will want to grow a variety that was bred to resist that disease.

We all have a favorite variety that we have gron or our parents have grown for years. So,

if your favorite variety is prone to a certain disease (when conditions are favorable for

that disease), and you just have to grow it, then I would say grow one or two, but [plant

other varieties resistant to the disease, that you and your family have fruit to harvest and

enjoy.

One other question I am asked is the difference between Open pollinated,

Heirloom and Hybrid varieties. Open pollinated (OP) varieties are ones that have been

grown for years and years by our parents and grandparents. They may or may not be an H

Heirloom variety. They have been selected for desirable characteristics (size, flavor,

color, leaf shape/coverage, etc.) and adapted to grow under local conditions and saved by

generations. By growing an open variety under certain conditions (isolated from other

varieties), you can save open pollinated seeds and use them year after year.

Heirloom varieties are at least 50 years, saved from generation to generation and

are open pollinated. They may or may not be available for sale from commercial garden

seed companies. They are loved for their delicious taste, color, or texture. Keep in mind,

they also may be prone to diseases and have other undersirable characteristics.

Hybrid seeds are the result of two discinct and distant parents of the same species.

Saving the seeds from a Hybrid variety is not advisable; the seed may be sterile or may

reproduce. However, if they do reproduct, the offspring may have the undesirable

characteristics from one or both parents. Hybrid seeds are developed for disease

resistance and other desirable traits. You have to purchase new seeds every year.

Open pollinated, Heirloom and Hybrid seeds not only apply to tomatoes, but most

other vegetables too. So, when purchasing seeds or plants, I hope this article will help

you make decisions or what may grow best in your garden this year.