Knowing seed catalog terms & symbols

By David Sprague

OSU Ext. master gardener volunteer

For many people, the gardening season starts deep in winter when their seed catalogs arrive.

Along with attractive pictures and tantalizing descriptions of plants, the catalogs can also contain cryptic terms and symbols that can be difficult to interpret. Here are some of the common ones:

• Annual, biennial, perennial: Annuals are plants that perform their entire life cycle in a single growing season. They may re-seed but they don’t come back from the root. Biennials are plants that take two years to complete their life cycle. The first year they establish themselves and the second year they bloom, produce seeds and die. Perennials are plants that will grow for three or more years. Some perennials can take many years to reach their full size.

• Hardiness zone: This term applies to perennials, telling you how much cold the plant can tolerate. The USDA has divided North America into 11 climate zones, with 1 being the coldest and 11, the warmest. Warm-weather plants in a cold zone won’t survive. For the Mahoning Valley, look for plants rated zone 5 or lower.

• Days to maturity: This term is a little tricky. It tells you the average number of days after you have set out transplants until they are ready to harvest.

• Open pollinated (OP), hybrids, heirlooms: Open pollinated means the pollination has occurred naturally. Hybrids are the combination of two varieties, crossed to produce a desired trait. Hybrids are not GMOs (genetically modified organisms). Hybrids have lots of advantages, including disease-resistance. An heirloom is an historic plant passed down through many years. Heirlooms are also open pollinated.

• Sun, shade, a dark/half-light circle symbol: Some plants need full sun while others like shade. Pay attention to this designation because a plant put into the wrong location will not thrive, and sometimes fails to survive.

• Determinate and indeterminate: Determinate plants will grow to a certain size and stop growing. Indeterminate plants will continue to grow for the entire season.

• A series of letters: Disease resistance is designated with letters such as V, F, N, T, A, LB. Try a disease-resistant variety if you have had disease problems in the past.

• Number of seeds: The number of seeds in a package. Be sure you know the number of seeds vs. the weight. This helps you plan your garden size.

• Direct sow or start indoors: Direct sow means the seeds are planted directly in the ground where you want them to grow. Start indoors means the seeds need to germinate and start growing indoors under grow lights.

• A flower pot symbol: This means the plant will do well in a container.

If you need more information on what to do once you have your seeds, look for upcoming classes from the OSU Extension master gardener volunteers.

Visit for more information on seed catalog terms.

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