December 9, 2005
Posted online: January 7, 2006
Understanding seed catalog
UNIVERSITY OF ILLINOIS
Seed catalogs and plant tags can tell you a lot, provided you
understand the "lingo," says a University of Illinois
Extension horticulture educator.
"If you understand the 'lingo,' you're on the
way to choosing just the right plant and handling it in just the
right way," says Greg Stack.
Seed catalogs, he notes, are miniature horticultural reference
books. They contain an array of seeds and plants to suit just
about everyone's tastes and needs.
"Catalogs are also fun to page through. Not only are the
pictures and descriptions colorful, they take the edge off the
cold winter days when you dream of adding what you see on the
page to that perfect spot in your garden," he explains.
But, when thumbing through seed catalogs, it is important to
understand the terms you will encounter, such as annuals,
perennials, F1 hybrids, number of days, hills, spacing
suggestions, determinate and indeterminate, deadheading,
monoecious, gynoecious, gynoecious hybrids, and letters like Vt,
EB, Al, F1, or TMV.
"Both flowers and vegetables can be either annuals or
perennials," Stack says. "Both can be started from
seed, but the annuals complete their life cycle in one growing
season and die with cold weather. They need to be replanted next
"Perennials will live for three or more years, returning
and often getting better with age. They do this from some type of
root structure or other underground organ that overwinters and
starts to re-grow in the spring."
Many of the newer seed offerings are designated as F1 hybrids.
While they may cost a little more, these seeds are the
culmination of the plant breeder's work to create something
with better garden performance, disease resistance, uniformity,
and outstanding flower or fruit production.
"F1 hybrids are the result of specific crosses, which
means that seed saved from these plants at the end of the season
will result in something totally different if planted next
season," Stack notes. "The resulting plants will not be
anywhere near as desirable."
Often the term "number of days" follows a
plant's name. This refers to the number of days expected to
pass before harvest. For crops that are planted from transplants,
it is the number of days after setting out the transplants. For
seed-grown crops, it is from when the seed is sown.
"Many times you will see reference made to planting crops
like cucumber, pumpkins, and squash in 'hills,'"
Stack says. "This does not mean you physically mound up the
soil into small volcanoes and plant the seeds at the top. It
simply means you put several seeds, usually three, in one
location on flat ground in a triangle pattern.
"If planting more than one 'hill,' just move over
the recommended spacing before planting the next three
"Spacing suggestions" is another term common in
plant descriptions. This distance is suggested in order to give
the plant sufficient room to grow, often resulting in a more
abundant harvest as opposed to very tightly grown plants that are
now in competition with each other and usually producing less and
Tomato growers will see references to "determinate"
and "indeterminate" varieties. The determinate types
tend to be shorter, more compact plants. The branches end in
flower clusters, creating a shorter plant. These are great for
small space gardens, container gardens, or for those who
don't like to do much staking.
Indeterminate types get tall and often need staking or caging
to keep them upright and off the ground. The ends of the stems do
not end in flower clusters and just keep getting longer and
"'Deadheading' sounds like a gruesome term but
you see it often in reference to flowers," Stack explains.
"This term simply means that the older flowers are cut off,
resulting in the plant producing more flowers.
"Deadheading is often done with zinnias, marigolds,
salvia, dahlia, geranium, and other larger, single-stem flowers.
If older flowers are left on the plant, fewer and fewer new
flowers are produced. So, for maximum flower production, 'off
with their heads.'"
"Monoecious" and "gynoecious" are terms in
the garden's "sex" story. It takes male and female
flowers to make things like cucumbers, melons, squash, and
pumpkins. These plants often have separate male and female
flowers on the same vine. They are monoecious.
"But breeders have developed all-female flower-producing
plants such as cucumbers," says Tack. "These are called
gynoecious. This creates the potential for more fruit in a
"But how can reproduction happen without a few male
flowers? Packed with the seeds of gynoecious cucumber seeds are a
few seeds of plants that will produce male and female flowers.
These are usually easy to find as they are often dyed pink or
blue. Make sure you plant a few of these in a row of your
gynoecious hybrids and your pollination problems will be
And what about the "alphabet soup" of the
"When shopping for tomatoes, you may see letters
following a variety name," Stack says. "Letters such as
'Vt,' 'EB,' 'A1,' 'F1,' or
'TMV.' They refer to the varieties' ability to have
resistance or tolerance to disease and the more letters the
"Plant breeders try to breed in resistance to common
disease. This limits or eliminates fungicide sprays and assures
you of a more productive harvest. Vt refers to verticillium wilt
(soil borne disease), EB refers to early blight (leaf disease),
F1 refers to fusarium wilt race 1 (soil borne disease), and TMV
refers to tobacco mosaic virus (viral disease)."
Source: Greg Stack, Extension Educator, Horticulture, firstname.lastname@example.org