Seeds and Seed Catalog Jargon

Seed catalogs arrive this time of year with appealing photos of vegetable crops that buoy our hopes for a bountiful garden. The sheer number of vegetable, flower, and herb offerings is breathtaking, with seed companies offering 20 to 40 new cultivars each year. These may be brand-new releases or just new for a particular company. I recently scanned a few catalogs and discovered ‘Home Run’ melon, ‘Naval’ carrot, ‘Double Take’ columbine, ‘Rouxai’ leaf lettuce, and ‘Green Machine’ zucchini.

Seed catalogs

Companies often tout All-American Selection (AAS) Winners, cultivars evaluated and selected by a well-known independent, non-profit organization. Some of the small seed companies carry seeds from the

Open Source Seed Initiative (OSSI), a group of breeders and seed companies committed to open-source breeding.

There are dozens of wonderful seed companies and organizations that are a click away. But please also consider supporting local businesses and farmer co-ops with your seed and transplant purchases.

Seed Swaps

Seed swaps offer another great way to get and share seeds. These events are fun, educational, and interactive. National Seed Swap Day is January 25, 2020:  http://seedswapday.blogspot.com/ (information not yet updated for 2020).

Seed and Cultivar Terms Frequently Encountered in Seed Catalogs

Cultivar– a cultivated variety of a specific crop. Example: ‘Red Ace’ is a beet cultivar. Cultivar is a contraction of “cultivated” and “variety” and is often used synonymously with “variety.”

Open-Pollinated– an in-bred variety where individual plants in a population cross-pollinate each other and poduce nearly identical offspring. When grown using appropriate precautions, these varieties “come true” when seed is saved year-to-year.

Hybrid- controlled cross-breeding of two distinct, inbred, open-pollinated cultivars. The seed harvested from the intentional cross will produce an F1 (first filial) hybrid. Hybrids tend to be vigorous, uniform, and productive, and many have some disease resistance. Producing hybrid seed is labor-intensive, accounting in part for the often higher price. Hybrid seed is not true to type: seed saved from this year’s crop and planted next year will not be uniform in appearance or identical to the mother plants. Therefore, hybrid seed must be purchased each year.

Heirloom– open-pollinated cultivars that persist because their seed is saved and passed down from one generation to the next. They contain valuable germplasm that would be lost without the efforts of individual gardeners, farmers, small seed companies, seed-saving groups, and the USDA. They often have a colorful history and add interest to the garden and dinner table. Heirloom cultivars vary widely in productivity and disease and insect resistance.

Treated Seed– may be coated with a chemical fungicide (usually pink or purple in color) to prevent injury from soil-dwelling diseases after seeds are planted. The most common crops treated are corn, pea, and bean. Another treatment is immersing seeds in hot water to kill pathogens on, and inside of, seeds.

Untreated Seed- seeds that are not chemically treated.

Organic Seed- harvested from crops that are grown and certified according to the USDA National Organic Program (NOP) guidelines. To be certified “organic” seed must be produced and handled by certified organic producers. The NOP requires organic farmers to plant organic seed unless it is not commercially available. You can grow vegetables organically at home using non-organic, untreated seeds. Related resource: Organic Seed Alliance (national education, research and advocacy organization.)

Disease Resistant – ability to resist or impede a disease-causing pathogen. The level of resistance may be high or intermediate. This can also apply to insect injury. For example, sweet corn cultivars with long, tight ear leaves resist corn earworm feeding. Cornell University has excellent charts for identifying and selecting disease-resistant cultivars.

Disease Tolerant– ability of a cultivar to tolerate a disease infection or adverse environmental condition (e.g., drought, cold temperature) without a significant reduction in growth or yield.

Indeterminate / Determinate– the shoots of indeterminate tomato cultivars continue to grow and branch throughout the growing season. The shoots of determinate type cultivars reach a certain length and terminate in a flower cluster. Determinate tomato cultivars range in height from less than 1 ft. to 5 ft. and are sometimes referred to as “self-topping.”

Days to Maturity (Days to Harvest)- the approximate number of days to harvest, either from planting seeds or transplants. For tomato, pepper, eggplant, muskmelon, watermelon, broccoli, cabbage, cauliflower, and Brussels sprouts it’s usually days from transplanting, and for all other annual crops it’s days from direct seeding.

Parthenocarpic- flowers are able to set fruit without pollination and fertilization (of ovule by sperm cell). ‘Tasty Jade’ and ‘Diva’ are cucumber examples. ‘Cavili’, ‘Partenon,’ ‘Dunja,’ and ‘Golden Glory’ are summer squash examples. Growing a seeded cultivar nearby will lead to seeds forming in the parthenocarpic cultivar.

I learned that one of my favorite zucchini cultivars, ‘Costata Romanesco’ is largely parthenocarpic. A Cornell University study reported that 58% of bagged female flowers set marketable fruits.

Gynoecious- flowers are predominately female, leading to more fruits per plant. Unlike parthenocarpic cultivars, gynecious cultivars require pollination. Some companies include a second cultivar to plant that has both male and female flowers (monecious). Otherwise, you’ll need to buy and plant a second variety. Expensive cultivars (e.g. ‘Socrates,’’Tyria’) are available that are both gynecious and parthenocarpic. Seeds cost more because of specialized breeding and increased yield potential.

Pelleted– small seeds (carrot, lettuce, onion) are surrounded by a clay pellet to make handling and planting easier.

Primed– pelleted seeds may also be “primed” to reduce germination time. Seeds receive enough water to almost germinate, and are then dried and stored. These primed seeds break dormancy and germinate quickly when planted. The process also shortens the seed’s storage life.

Bolting (going to seed)- flowering prematurely, usually due to unsuitable climatic conditions at certain stages of growth. Spinach, lettuce, cilantro, broccoli, and endive are crop species prone to bolting.

Do you have a few favorite cultivars you’d like to share with us?

We would love to know which vegetable cultivars you would recommend to your fellow gardeners. Please send a list of your favorite cultivars to jont@umd.edu with a few words or a few sentences about why you like them (e.g., high yields, dependable, early maturing, heat tolerant, disease resistant, etc.)

By Jon Traunfeld, Extension Specialist

Winter Sowing: How I Get a Jump Start on My Summer Flower Garden

poppies
These June-blooming flowers were started by winter sowing. Photo: C. Carignan

Winter sowing is a technique gardeners can use to start growing seeds outdoors during the winter months. If you have limited space for starting seeds indoors, winter sowing might be an option for you, depending on what you want to grow.

I first tried winter sowing last year with several types of flower seeds. Winter sowing works best for plants that are cold tolerant or even require a period of cold in order to germinate. When you are looking at seed descriptions, look for words like “cold tolerant,” “cool season”, “hardy annual,” “perennial”, “sow in autumn”, “sow in early spring”, or “self-sows”. These words indicate the best candidates for winter sowing. Continue reading

Light Choices for Starting Plants Indoors

There seem to be new lighting choices for indoor plant growing every year. If you’ve been starting annual flower and vegetable plants indoors you probably learned early on that natural light entering through windows is hardly ever adequate. Some type of supplemental light is essential to produce healthy transplants. But what types of bulbs and fixtures work best? And how much money do I really want to spend on something I’ll use for 8-12 weeks each year?

Fluorescent Lights

Many gardeners use 2 ft. or 4 ft. long fluorescent tubes in a fixture (a.k.a “shop light”). The T number is the tube diameter in 1/8 inch units. The traditional T12 tube (1 ½ in. dia.) has been largely replaced by slimmer T8 (1-inch dia.) and T5 tubes (5/8 inch dia.). All fluorescent tubes give off a small amount of heat– rarely a problem, even when foliage grows into them. Heat from the ballast in the fixture can help hasten germination and plant growth, especially when your set-up is covered with plastic.

PVC light stand
PVC light stand with 4 ft. long T5 fluorescent fixtures. Plants stretch to reach available light.
To produce stocky plants the tubes should be only a few inches from the plant tops.
Photo:  Jon Traunfeld

LED Grow Lights

Light-emitting diodes (LEDs) give off very little heat, use less energy than fluorescent tubes, and last about twice as long. They are also mercury-free and made from plastic so won’t shatter like glass. LEDs appear to be the wave of the future for indoor lighting. Horticulturists and lighting engineers are working worldwide to customize wavelength combinations for specific plant production goals in commercial greenhouses and indoor vertical farms. Continue reading

Microgreens: Tasty Accents from Small Spaces

My first response to microgreens was: “Why would I spend my time growing 3-inch tall plants to eat?”

Then I thought about all of the tiny leafy green plants (beet, lettuce, kale, basil, etc.) I had eaten over the years in the process of growing transplants at home and in greenhouses. And it started to make more sense: why not plant seeds closely in a container to just grow baby plants?

"Brassica" microgreens
Tray of “brassica” microgreens ready to harvest

Benefits: When you eat microgreens you are ingesting the cotyledons, stems, and small expanded true leaves of edible plants. Some reasons to give them a try:

  • High in anti-oxidants and other health-promoting substances, like vitamin C, vitamin E, beta-carotene, and lutein
  • Can be grown year-round inside with strong natural light or inexpensive fluorescent tubes
  • Great for kids at home and in school- sow seeds, watch them sprout and grow for 10-14 days, and eat!
  • Wonderful assortment of colors, flavors, and textures

Continue reading