A Seed-Starters Glossary

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You don’t understand the language used in seed catalogs? You’re not alone! Source: www.barnesandnoble.com, pngimg.com & journalofantiques.com, montage jardinierparesseux.com

Seed and plant catalogs wing your way to your door and pop up on your screen. Garden centers are full of displays of seed packets of all kinds. It’s so exciting! You dive in and try to pick out the very best plants for your use. But the vocabulary found on the back of seed packs and in printed and virtual seed catalogs can be arcane, even confusing. For many beginners, it’s like reading a foreign language! To help you, here are a few terms you may encounter and their definitions.

Acclimatization: A vital action taken just before transplanting seedlings outdoors. It simply means to place the seedlings, still in their pots, outdoors in the shade for 2 or 3 days, then in partial shade for 2 or 3 days, then in full sun for 2 or 3 days. The seedlings are now “hardened off” and ready to transplant to their permanent location.

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Annuals grow quickly, but die after they bloom. They leave seeds to start a new generation. Illustration: Twinkl

Annual: a plant that completes its life cycle, from germinating to seed production, in one single year, then dies. Ex.: cosmos, marigold, sunflower.

Hardy Annual: an annual that tolerates cool soil and even a bit of frost. It is usually sown directly in the garden, early in the spring. Ex.: spinach, sunflower.

Half-Hardy Annual: an annual that tolerates could soil, but not frost. It is usually sown indoors in short-season or cool climates, but directly outdoors in warmer ones, as soon as there is no risk of frost. Ex.: cosmos, lettuce, petunia.

Tender annual: a plant grown as an annual that needs constant warmth and will not take frost. In all but tropical climates, it is generally started indoors and transplanted into the garden when both the soil and air have warmed up and there is no risk of frost. Ex.: basil, begonia, tomato.

Biennial: a plant that completes its life cycle in two years, usually producing a rosette of leaves the first year and flowers and seed the second. It dies after seed production. Ex.: foxglove, parsley.

Perennial: a herbaceous plant (not woody) that lives more than two years and that blooms more than once. It does not die after flowering.

Botanical Name: see Scientific Name.

Bush-type: see Non-Running.

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Leaf suffering from chlorosis. Source: utahpests.usu.edu

Chlorosis: when leaves contain insufficient chlorophyll. They are often pale, yellow, or yellow-white. An iron deficiency, or lack of iron, is a common cause of chlorosis. See Nutrient Deficiency.

Cold Treatment (Stratification, Vernalization): subjecting to cold temperatures seeds that need to go through a cold period before germinating. Usually they are sown in pots of moist soil and placed in a refrigerator for several weeks before exposing them to heat. An alternative is to sow them outdoors in the fall in a cold climate where they will naturally undergo cold temperatures. Many perennials, shrubs, and trees from temperate climates require a cold treatment.

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Seedling with two cotyledons. Source: www.canolacouncil.or

Cotyledon: a seed’s first leaf, usually simple and often very different in appearance from mature leaves. Most seedlings have two cotyledons, but there are seedlings with only one cotyledon, more than 2 cotyledons and without any cotyledon.

Cross-Pollination: The transfer of pollen from the anther of a flower of one plant to the stigma of a flower of another plant of the same species. It is usually carried out by insects, birds or wind.

Cultivar: a plant raised and multiplied by humans, that does not exist in nature. Its name is typically written between single quotes (‘   ‘). The name derives from “cultivated variety.” Ex.: in Cosmos bipinnatus ‘Sonata White’, ‘Sonata White’ is the cultivar name.

Determinate: said of a tomato plant (and a few other plants) in which each branch ends in a cluster of flowers, which therefore limits its upward growth. Determinate tomatoes make fairly small plants and don’t always need staking. They tend to produce all their tomatoes at about the same time.

Indeterminate: said of a tomato plant (and a few other plants) whose flowers appear in the axils of branches and not at the stem tip. Therefore the stem continues to grow in height throughout the growing season. These tomatoes need staking or a large tomato cage. They may produce less fruit at once than a determinate tomato, but usually do so over a long harvest season and often give double or triple the yield of a determinate tomato.

Dioecious: refers to a plant whose male and female flowers are borne on different plants. The asparagus is dioecious.

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Male (left) and female (right) squash flowers. Squash plants are monoecious, thus flowers of both sexes are borne on the same plant. Source: www.missouribotanicalgarden.org

Monoecious: refers to a plant that produces separate male flowers and female flowers on the same plant. Often the female flower is easily recognized because it has a small ovary at its base in the shape of the fruit to come. Squash, melons and cucumbers are monoecious.

Perfect Flower (Bisexual Flower, Hermaphroditic Flower): said of a flower that has both male and female organs, thus both a stigma and stamens. This is the most common situation in nature.

Direct Sowing (Direct Seeding): sowing a plant directly outdoors where it is to grow. Beans, marigolds, and corn are often direct sown.

Do not cover: said of a seed that should not be covered with soil at sowing, usually because it is either very fine or requires light to germinate, or both.

GMO: genetically modified organism. Said of a plant into which humans have inserted genetic material from another plant or even an animal without going through pollination. There is, for example, corn containing the genes of Bt (a bacterium) and varieties of canola and soybean which with inserted genes that make them resistant to herbicides. At the time of writing this, there are no GMO seeds or plants available to home gardeners.

Hardening Off: see Acclimatization.

Heirloom Vegetable (Heirloom Plant): an old variety. Some authorities consider a plant having been introduced more than 50 years ago to be an heirloom variety, others prefer the definition “before the 1940s.” Most heirloom vegetables are produced through open pollination, that is pollination carried out by insects, birds, or wind. Examples.: ‘Brandywine’ tomato, ‘Golden Bantam’ corn, etc.

Hybrid: plant resulting from the crossing of two different breeds, species or genera. F1 hybrids are the most common type of hybrid and are the result of a first-generation cross (F1 means “1st filial generation”). Usually, F1 hybrids are more robust than non-hybrid plants, but more expensive, because they have to be manually pollinated in a greenhouse setting. F2 hybrids, less common on the market, are seeds of F1 hybrids, thus the second generation (2nd filial generation). They are cheaper, as they are generally produced by natural pollination, but tend to give less reliable results than F1 hybrids.

Last Frost Date: see Spring Frost-Free Date

Latin Name: see Scientific Name.

Nutrient Deficiency: results from the lack of a vital mineral in the soil (phosphorus, potash, nitrogen, zinc, boron, iron, etc.). It can have various symptoms include discolored or deformed leaves or slow growth. Treatment with a complete fertilizer (containing all the trace elements, such as a seaweed or fish fertilizer) will usually overcome a deficiency.

Organic: various definitions. Organic seeds are harvested from plants that have not been treated with synthetic (that is to say, chemical) pesticides or fertilizers. Organic pesticides and fertilizers are derived from natural sources, not from chemical synthesis.

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Peat pots. Source: amazon.com

Peat Pot: pot made of pressed peat, coir or other organic materials, usually used for seedlings that will not tolerate transplanting. The peat pot allows roots to grow right through its sides and bottom and can therefore be transplanted into the garden without removing it. The roots of the plant will then grow right through the peat pot into the surrounding soil.

Pelleted Seed, Seed Pellets: seeds covered in a product (usually clay) which facilitates their handling.

Multi-pellets: seed pellets that include several seeds and are used for plants that look best when grown in a clump, such as bedding lobelias.

Pinching: removal of a plant’s terminal bud (bud at the end of the stem). Pinching stimulates branching, giving a more compact and attractive plant, but may delay flowering. It is traditionally done by “pinching” the top growth between the thumb and forefinger, but can also be done using pruning shears or scissors.

Requires Light to Germinate: said of a seed that germinates only in presence of light, be it sunlight or artificial lighting. These seeds should be sown without covering them with soil and the pot should be placed in a brightly lit spot.

Running: said of a squash with long creeping stems that require a lot of space in the garden, like a pumpkin. This is the natural state for squash.

Non-Running (bush type): said of a squash that produces a short stem and a rosette, taking up less space in the garden than a running squash. The zucchini is the best known non-running squash.

Scarification: action of filing, nicking, or cutting a seed before sowing it. It can also involve soaking it for several hours in warm water. The goal of scarification is to penetrate very hard seeds (morning glories, hibiscus, etc.) and thus accelerate their germination.

Scientific Name (Botanical Name, Latin Name): it consists of two words, the first being the genus name (name shared with related plants, much like a human surname) and the second, the specific name, which determines the plant accurately. For example, Solanum tuberosum is the scientific name of the potato and Solanum melongena, of the eggplant. Both share the same genus name, Solanum, because they are closely related, while the specific name serves to make it clear to which type of Solanum the writer or speaker is referring. The scientific name is usually written in italics when possible.

Self-fertile: refers to a plant whose flowers can self-pollinate, that is to say that its own pollen can ensure seed production. Most plants are self-fertile.

Self-sterile: said of a plant which has to be pollinated by another variety in order to produce seeds. Many fruits (apples, pears, plums, cherries, etc.) are self-sterile or partially self-sterile. In their case, it is always best to cultivate at least two cultivars of the same species nearby, as cross-pollination is necessary for them to produce abundant fruits.

Spring Frost-Free Date: the date used in calculating when to start tender plants indoors, referring to the approximate date when you can expect there is no longer any risk of spring frost, usually about 2 to 3 weeks later than the average last frost date. (About one year out of two, there will be frost after the last average last frost date: that’s why it’s an average.) On seed packs and in seed catalogs, you’re often told to start seeds indoors so many weeks (6 weeks, 8 weeks, etc.) before the spring frost-free date. You can ask a local garden club or garden center for the last frost date in your region, then simply count backwards to find the right date for sowing seeds.

Stratification: see Cold Treatment.

Thinning: removing some seedlings or fruits in order to allow room for others to grow better. Usually this is done by cutting the excess plants or fruit stalks the base.

Transplanting: moving a plant from one place to another. In the case of seedlings, this is usually from the pot in which they were sown into a larger pot or into the ground.

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Treated seed is inevitably stained bright colors to avoid any confusion with non-treated seed. Source: http://www.sulphurmills.com

Treated seed: seed has been treated with a fungicide to prevent rot in cold or wet soils. This treatment is not considered acceptable to organic gardeners.

Untreated Seed: seeds that have not been treated with fungicides and therefore acceptable in organic gardening.

Vernalization: see Cold Treatment. It can also mean subjecting growing plants to cold in order to stimulate flowering.20180420A ENG www.barnesandnoble.com, pngimg.com & journalofantiques.com .jpg

The Tall and Short of Tomatoes

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Indeterminate tomatoes are taller and bear their fruit over a long season. Determinate tomatoes produce shorter plants and produce their fruits nearly all at once. Illustrations: organicsoiltechnoloogy.com

Determinate and indeterminate are two terms you’ll often see applied to tomato plants (Solanum lycopersicum) and they cause a bit of confusion with beginning gardeners… and even some fairly advanced ones. The two terms refer to how the plant grows and, indirectly, to the eventual size of the plant. Here’s my explanation:

20180330B organicsoiltechnoloogy.com..pngThe main stem of a determinate tomato ends in a cluster of flower buds and its secondary branches also end in flower buds. As a result, it stops growing in height fairly early in the season. The exact height does vary according to the cultivar, but determinate tomatoes remain quite compact plants and don’t really need much in the way of staking. The entire plant tends to flower nearly all at once and, as a result, the fruits all ripen at about the same time. These are the tomatoes you see growing in commercial fields: the fact that there are no stakes to worry about and that the fruits mature all at once means they are easily harvested by machine. For gardeners into canning and preserves, their “all ready at once” characteristic is also ideal.

Determinate tomatoes also tend to be earlier than indeterminate tomatoes and therefore good choices for climates with short growing seasons. The down side is that they produce fewer tomatoes than would a similar indeterminate tomato.

20180330C organicsoiltechnoloogy.com.pngIndeterminate tomatoes have totally different growth habit. The tip of the stem doesn’t end in flower buds, but continues to grow upward. Flowers are instead produced on side branches. They are climbing plants and will need good staking. It’s not unusual to see indeterminate tomatoes, like the very popular ‘Sweet 100’ reach 8 feet (2,5 m) or more in height, even in temperate climates, only stopping when frost cuts them down. And in tropical climates, the sky is the limit. The tallest indeterminate tomato ever reached 19.8 m in height: that’s 65 feet!

Indeterminate tomatoes produce many more fruits than determinate tomatoes of similar types, often 3 or 4 times more, but do so over a long period, a few here and a few there, not all at once. Plus, they’re later to come to maturity than determinate tomatoes. They’re especially interesting when you like cooking with fresh tomatoes, as you’ll have fresh fruit continuously over a very long season.

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You need really big, strong tomato cages for most indeterminate tomatoes. Source: www.theunconventionaltomato.com

Indeterminate tomatoes are the ones on which work-obsessed gardeners spend hours pruning off the so-called suckers. And if you do use the traditional 1 stake per plant staking method, you may have to do just that: it would be very difficult to fix all those branches to a single stake. When growing indeterminate tomatoes, though, you can avoid all that effort. Just use large tomato cages and simply push any wayward branches back inside the cage, so no pruning is required. That way, you get a much bigger yield, as those “suckers” are really branches and will produce tomatoes if you let them.

There are also semi-determinate tomatoes: taller than determinate tomatoes, but with a similar habit. However, not so tall you need a ladder to harvest them.


Please note that tomato growth habit does not affect fruit size, taste or color. You can find cherry tomatoes, slicing tomatoes, paste tomatoes, yellow tomatoes, pink tomatoes, etc. in all three groups.

As a gardener, I like to grow an especially early determinate tomato or two for an early harvest, but really bank on the indeterminates to supply most of my crop, offering me ripe tomatoes I can bite into until well into autumn.

Most tomato seed packets are clearly labeled determinate or indeterminate. If you buy tomato plants, though, you’re often given nothing more than a cultivar name, if that. You’ll have to ask the vendor what type it is!20180330A ENG organicsoiltechnoloogy.com.jpg