How to understand a seed catalog

By Diana Stoll
Updated 1/29/2018 1:29 PM
  • Seed catalogs are easy to read for veteran gardeners, but those new on the scene may have a few questions.

    Seed catalogs are easy to read for veteran gardeners, but those new on the scene may have a few questions.

We gardeners suffer from a bit of garden withdrawal in the winter. Seed catalogs help us dream of the season to come and keep our green thumbs busy highlighting must haves and making wish lists.

Veteran gardeners read seed catalogs with ease. Years of experience have taught them the definitions of terms used by horticulturalists who write plant descriptions and gardening tips.

Less experienced gardeners, on the other hand, may be overwhelmed by some of the lingo.


A hybrid plant occurs when plant breeders select two different parent plants with specific desirable traits to create a new improved plant, or hybrid, with its own set of characteristics. Hybridizers often cross-pollinate in hopes of creating plants with better disease resistance, vigor, better yield, early maturity and color. Seed savers avoid hybrids because plants grown from their seeds will not be the same as the parent plant.

Open-pollinated (OP)

Open-pollinated plants result from pollination by bees, insects, wind or itself if the plant has both male and female flowers (ex: cucumbers, melons, pumpkins and squash). Seeds of these plants often come true to type but because pollinators visit varieties planted close to each other, they can also be genetically diverse. Open-pollination can be accomplished by gardeners as they hand pollinate vegetables to promote a better yield.


Heirloom varieties are open-pollinated plants that are more than 50 years old. Most heirloom varieties have been passed down through generations of a family, community, or region of the country. Heirlooms have been selected by gardeners for a specific characteristic and believed by many to have better flavor. The growth and harvest of heirlooms is less predictable.


Genetically modified organisms (GMOs) are the genetically engineered offspring of two completely different species. They are created in laboratories using high-tech processes. Examples of GMO vegetables include RoundUp Ready corn and soybeans. At least for now, GMO seeds are not offered in garden centers or seed catalogs.


Organic seeds are grown without the use of synthetic materials like chemical fertilizers and pesticides. To be certified organic in the U.S. plants must be grown on land that has not had prohibited substances applied for at least three years before harvest.

Treated seeds

Treated seeds are coated with a fungicide. Peas and pumpkins are two examples of seeds that are often available to order either treated or untreated.

Direct sowing

Seeds planted directly in the garden or in a container outdoors are direct sown. Cool season vegetables like beets, carrots, kale, kohlrabi, lettuce, radishes, and spinach can be planted when temperatures are still cool. Warm season vegetables like corn, cucumbers, pumpkins and squash can be direct sown after the soil has warmed and the danger of frost has passed.


Some vegetables need more time to reach maturity than the growing season provides. Seeds of these plants should be sown indoors and then planted outside as transplants after the last frost date. Transplants are also available at local garden centers in spring.

Pelleted seed

Some seeds are tiny -- barely larger than specks of dust -- and hard to handle. Pelleted seeds have been coated with an inert material. These larger seeds make correct spacing easy. Pelleted seeds are also easy for children to plant. Carrots, lettuce, onions and parsnips are often available in pelleted form.


Most often used when describing the growth habit of tomatoes, determinate varieties do not require pruning; may or may not require staking; and the tomatoes ripen over a genetically determined period of time.


Opposite of determinate varieties, indeterminate varieties grow very tall; require strong supports; need pruning to achieve the best results; and the tomatoes ripen over many weeks in summer.

What are those capital letters in tomato descriptions?

You will notice abbreviations in tomato descriptions. They represent the diseases to which the variety shows resistance (EB-Early Blight; F-Fusarium Wilt; LB-Late Blight; V-Verticillium Wilt). It doesn't mean the variety can't succumb to the disease, but is less likely than its cousins. Seed catalogs provide a key.

Now grab a pen and a highlighter and dig in to those seed catalogs.

• Diana Stoll is a horticulturist, garden writer and the garden center manager at The Planter's Palette in Winfield. She blogs at

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