How to understand horticulture speak

Winter afternoons spent with a warm drink and the newest seed catalogue may not be everyone’s idea of a fun time but avid gardeners will certainly understand what I mean. Growing plants from seed is one of the most rewarding, not to mention economical, things a gardener can do. There’s something almost magical about planting tiny seeds in a container with growing medium, misting carefully and setting it in an area to receive warmth and light. In a few days, or weeks, or months (all depending on the plant we are growing) a little speck of green appears.

Deciphering seed catalogues can be a bit daunting for new gardeners. There are Latin names, unfamiliar terms, abbreviations and so many different types of flowers, vegetables and herbs that it’s hard to know where to begin. The majority of garden catalogues offer a large selection of annual vegetable, herb and flower seeds and a smaller amount of perennial herbs and flowers and a few carry seeds for woody plants. Most new gardeners usually begin with a few packages of seeds for annuals and after experiencing the headiness of success will often move on to plants which require a bit more effort to coax from seed. Before they know it, they’re setting up light stands with heat mats and humidity tents to go the whole nine yards.

Here are a couple of tips to make navigation through seed catalogues a little easier for newbies:

Botanical names: The use of botanical names is the international system for plant identification as each name refers to only one specific plant. This avoids any confusion as there are many common names for the same plant in different countries and sometimes even different parts of the same country, not to mention how many different languages there are worldwide. The first word in a botanical name refers to the genus (plant family) and the second name is the specific ephitet which describes the particular features of that plant. For example, the botanical name Acer palmatum refers to Japanese maples. Sometimes there is another name which follows the genus and specific ephitet which can either refer to a variety or a cultivar. A variety occurs naturally in nature where as a cultivar (cultivated variety) is derived by human intervention of cross breeding two parent plants to achieve desired results. The botanical name for the purple Japanese maple is Acer palmatum Atropurpureum.

Annual: An annual is a plant which completes its life cycle within one growing season. It grows from seed, blooms, sets seeds and dies all within the same year. Annuals are further classified in seed catalagues as HA (hardy annual), HHA (half-hardy annual) or TA (tender annual). Most annuals are easy to grow from seed and are the best bets for beginners. TP indicates a tender perennial.

Hardy annual – These grow best in cool climates and can tolerate a certain amount of frost. Seeds can survive winter temperatures and can be sown outdoors in autumn to germinate the following spring. Calendula (pot marigold), Centaurea cyanus (bachelor’s button), Cleome (spider flower), Consolida ambigua (larkspur) are all hardy annuals.

Half-hardy annual – Plants hold up in cool, damp weather and can tolerate light frosts but not prolonged exposure to sub-zero temperatures. Seeds should be sown indoors and set out after the last frost date (usually the end of May). Gomphrena globosa (globe amaranth), Moluccella laevis (bells of Ireland), Salvia splendens (scarlet sage).

Tender annual – Plants cannot tolerate any exposure to frost and need warm temperatures and warm soil in order for seeds to germinate. Examples: Amaranthus tricolor (Joseph’s coat), Tagetes erecta (African marigold) Tagetes patula (French marigold)

Tender perennial – Plants which are perennial in their native environment but not hardy enough to withstand winter temperatures. These plants are grown as annuals in our climate but can live for years if overwintered indoors. Rosmarinus officianalis (rosemary), Pelargonium x hortanum (geranium); Heliotropium arborescens (heliotrope).

Biennial: The life cycle of biennial plants takes two seasons. The first growing season produces foliage which dies to the ground at the onset of winter but the roots remain alive. During the second growing season, the plant produces flowers and sets seeds. Dianthus barbatus (sweet William), Campanula medium (Canterbury bells)and Lunaria annua (Honesty) fall into this category.

Herbaceous Perennial: These plants live for at least three years but most have a much longer lifespan. The top growth dies back to the ground when the plant goes dormant for winter but the root systems are very much alive. Most perennials grow from crowns (the point where the stem meets the roots) and when the stems die back in fall, growth buds or eyes form on the new crowns.

AAS/Fleuroselect: Each year new plants are grown in trial gardens around the world to assess their performance under various conditions. Gold medal winners are those which achieved outstanding overall performance. AAS refers to All-America Selections. Fleuroselect is the international organization for the trial and promotion of flowering plants. Seeds of plants which are identified as AAS or Fleuorselect winners are usually more expensive but are worth the extra amount.

F1 hybrid: These plants are the first generation of two specially selected parent types which are cross-pollinated for a specific outcome. This may be better performance, disease resistance, consistent flower size and habit, etc. As it takes considerable research and time to produce these hybrids, seeds are more expensive than other types. The disadvantage with F1 hybrids is that you cannot save seeds produced by these plants as they will not come true from seed.

Antique/Heirloom seeds: These plants have been grown for generations and have adapted well to a particular area or climate. Seeds are open open-pollinated and saved at the end of each growing season and handed down through the years by families and friends. Open-pollination refers to seeds which occur by natural means (wind, insects, etc.) and not by human intervention. Most vegetables grown for commercial use have been hybridized for a number of reasons: heavier yields, to be picked when green and gas ripenend, or to have uniformity of shape so as to be easily packed and not bruised during shipping. Heirloom vegetables are usually better tasting, the plants have adapted to the area and so are not as succeptible to local pests and diseases, don’t ripen at once which gives a longer season for harvesting by home gardeners, and best of all, the seeds are free.

Certified Organic Seed Plants are grown according to true organic agricultural or horticultural practices where no synthetic fertilizers, chemicals, pesticides or herbicides are used. Organic fertilizers also act as soil conditioners and composted manure, seaweed, blood meal and bone meal are commonly used in organic farming.

GMO Genetically modified organisms are produced in labs where genes from a particular species are extracted and placed into genes of an unrelated species. Commerical sale of GMO foods began in the mid-1990s. It focused mainly on cash crops as these plants were engineered for resistance to pathogens and herbicides and said to result in greater yields. GMO seeds are owned by corporations and are protected by intellectual property rights and therefore cannot be saved by farmers or home gardeners. Monsanto is the largest seed company and owns over 80 per cent of GMO seeds grown globally.

Pelleted/Treated seed: Some seeds are coated with herbicide or fungicide to resist infestations from soil borne insects or fungal diseases such as damping off. They are usually brightly coloured to differentiate from other untreated seeds. Letters refer to particular disease/pest resistance. For example, V — verticilium wilt, F —fusarium wilt, A — anthracnose, etc.

Viability refers to the length of time seeds are capable of germination. Some seeds remain viable for hundreds of years while others may last for only a few weeks. Once purchased, seeds are best stored in cold, dry conditions. A sealed jar in the refrigerator (not freezer) is adequate for most seeds.

Pretreatment – Some types of seeds need special treatment before they will germinate. This usually replicates the conditions of their natural environment.

Stratification – Seeds of some plants native to areas with cold winters need a period of cold treatment in order to germinate. Usually the temperature inside most refrigerators is adequate but some types need to be subjected to freezing temperatures for a period of time. For example, perennials like columbine, monkshood, and summer phlox all need about a month of cold temperatures before germination can occur.

Scarification – Some seeds have a hard seed coat which needs to be softened before germination can take place. In nature, this is accomplished by weeks of spring rain. Gardeners can imitate the process by nicking or filing the hard seed coat and then soaking the seeds in warm water until they swell. Morning glory, sweet peas and lupins benefit from this treatment.

Double Dormancy – Seeds of certain types of plants need to undergo periods of alternating warm and cold temperatures before they will begin the germination process. These seeds ripen in fall and germinate in spring a year or two later. Some native shrubs like serviceberry, sumac and viburnum need this process in order to germinate.

I am happy to answer your garden questions, preferably by email: [email protected].

Marsha Middleton is a Horticulturist (UG), Landscape Designer and Garden Consultant who lives on the South Shore.