Decoding Seed Packets; or, What do all those abbreviations mean?!

It’s that time of year again. Seed catalogs are starting to pile up everywhere throughout the house. And I mean everywhere. I don’t think there’s a single room that doesn’t have at least one catalog. Each of them is filled with sticky notes, folded pages, and pen marks. Mostly I’ve scribbled X’s and O’s but there’s quite a few ?’s as well.

I’m always fascinated to read about all the different varieties, and their photos are a welcomed splash of green in the dead of winter, but all of my question marks were related to a bunch of odd abbreviations and a few new words. What do they mean?

Let’s start with the words.

Heirloom, this is an old variety that owes its existence in large part to the seed-saving efforts of amateurs. These may have been commonly grown during earlier periods in human history, but are not used in modern large-scale agriculture. Many heirloom vegetables have kept their traits through open pollination, while fruit varieties such as apples have been propagated over the centuries through grafts and cuttings.

Hybrid, this is the offspring of a cross between two or more varieties, usually of the same species. You’re a hybrid of your mom and dad, while a liger is the cross between a lion and a tiger. No, really, I’m not kidding.

Inoculation, this is the introduction of beneficial bacteria to legumes to ensure the formation of high-nitrogen nodules on their roots.

Priming, this is a process by which the temperature range and speed of germination are expanded, as well as additional priming to break light dormancy when needed. Many lettuce seeds, for example, are primed to enhance germination. The priming process, however, decreases the storage life of the seed.

Scarification, this term applies to seeds that have a very hard outer coating. You’ll need to nick or break the outer coat so that moisture can penetrate and germination can begin. This is usually accomplished by using a sharp knife or sand paper to penetrate the outer coating. If this procedure is not followed on seeds that require it you will have a very low or zero germination rate.

Stratification, this term means the seeds need to be exposed to cool temperatures for a set amount of time. This term usually applies to perennials and biennials. If the seeds are not given a cold period, again you will have a zero or very low germination rate.

Now for those abbreviations.

(AAS) All-America Selection: The AAS Winners offer gardeners reliable new varieties that have proven their superior garden performance in trials across North America, thus, their tagline of “Tested Nationally and Proven Locally”.

(F1) or (F2) Filial Generation: This may seem vaguely familiar if you ever did punnett squares in high school biology.

(OG) Organic: Seeds harvested from plants that were grown without synthetic fertilizer and pesticides.

(OP) Open Pollinated: pollination occurs by insect, bird, wind, humans, or other natural mechanisms. Because there are no restrictions on the flow of pollen between individuals, open-pollinated plants are more genetically diverse. This can cause a greater amount of variation within plant populations, which allows plants to slowly adapt to local growing conditions and climate year-to-year.

Sweet corn has a few abbreviations all its own. Each represents the expected ratio of starch and sugar contained in the kernels of each ear.

(su) These kernels contain both starch and sugar.
(se) These are called sugary enhanced and their sweetness lies somewhere in the middle.
(sh) These are the sweetest and they appear shriveled when dry.

The overwhelming majority of abbreviations refer to a plant’s resistance to particular viruses, fungi, and bacterium…
A ➝ Anthracnose
AB ➝ Alternaria (Early) Blight
ALS ➝ Angular Leaf Spot
AS ➝ Alternaria Stem Canker
B ➝ Bacterial Wilt
BB ➝ Bacterial Blight
BBS ➝ Bacterial Brown Spot
BLS ➝ Bacterial Leaf Spot
BMV ➝ One or more races of Bean Mosaic Virus
BYMV ➝ Bean Yellow Mosaic Virus
CMV ➝ Cucumber Mosaic Virus(“Blight”)
CTM ➝ Curly Top Beet Mosaic Virus
DM ➝ Downy Mildew (with specific races)
E ➝ Enation Mosaic Virus
F ➝ Fusarium Wilt (Race 1)
F2 ➝ Fusarium Wilt (Races 1 & 2)
F3 ➝ Fusarium Wilt (Races 0, 1, & 2)
HB ➝ Halo Blight
L ➝ Grey Leaf Spot
LB ➝ Late Blight
LM ➝ Resistant to Leaf Molds A-E
LMV ➝ Lettuce Mosaic Virus
MNCLB ➝ Moderate Northern Corn Leaf Blight
MR ➝ Moderate Common Rust
MSCLB ➝ Moderate Southern Corn Leaf Blight
MSW ➝ Moderate Stewart’s Wilt
MT0-10 ➝ Indicates seeds have been tested for Lettuce Mosaic Virus, and that none was found in a sample of 10,000 seeds or less.
MT0-30 ➝ Indicates seeds have been tested for Lettuce Mosaic Virus, and that none was found in a sample of 30,000 seeds or less.
N ➝ Nematodes
NCLB ➝ Northern Corn Leaf Blight
PLR ➝ Pea Leaf Roll Virus
PM ➝ Powdery Mildew
PMV ➝ Pepper Mosaic Virus
PVY ➝ Potato Virus Y
PY ➝ Pythium Resistance
R ➝ Common Rust
S ➝ Scab
SCLB ➝ Southern Corn Leaf Blight
SW ➝ Stewart’s Wilt
TEV ➝ Tobacco Etch Virus
TMV ➝ Tobacco Mosaic Virus
TSWV ➝ Tomato Spotted Wilt Virus
V ➝ Verticillium Wilt
W ➝ Common Wilt
WR ➝ White Rust