The Seed Savers Exchange (SSE) is a non-profit organization saving heirloom garden seeds from extinction. Their members grow varieties from around the world, including those brought to America by family immigrants and traditional varieties grown by Amish and Mennonites.
A seed is a mature ovule containing a miniature undeveloped plant embryo and food reserves enclosed in a protective coat (testa). Seeds “wake up” and grow when environmental conditions are right for them.
What is a seed?
A seed is a fertilized, mature ovule that contains an embryo or miniature undeveloped plant plus stored food materials. It is enclosed within a protective covering (the seed coat). A seed is the biological way that flowering plants reproduce. Seeds develop from the ovary of a flower after pollination. In gymnosperms, seeds form on scales of cones and in angiosperms they ripen into a fruit such as a pome or nut.
A plant’s capacity to produce seeds varies from year to year in response to weather variables and internal cycles. A good seed crop is essential for forest regeneration and for the production of quality timber. In natural plant populations, seeds are dispersed by wind, birds and animals. Some seeds, such as those of dandelion or acorn, have wings to help them fly and many—including Brazil nut seeds and sea-beans—have buoyant parts that allow them to float far from their parent plant, where they can land at a place and time favorable for germination.
What happens inside a seed?
Seeds come pre-packaged with an embryo, food reserves and vital genetic information to become a plant like its parents. Inside, the embryo is surrounded by a hard seed coat and nutrient-rich endosperm. The seed monitors the environment for ideal conditions specific to that species and remains dormant until it finds them. When the seed is soaked in water, a process called imbibition, enzymes begin to hydrate and the outer seed coat swells and breaks open. Cells start respiring and metabolizing the food stored within the seeds.
Seeds come in a wide variety of shapes and sizes, some have fleshy appendages to entice animal dispersers to eat them; others have hooks or barbs to attach to fur or feathers; still more float on water or are spread by wind. Some seeds are even equipped with wings or fins to help them fly away on a current. Then, when they find their way to the soil, they start growing! The first sign of growth is the radicle, a tiny root that emerges from the embryo.
How do seeds grow?
Seeds require a suitable environment, water and oxygen to begin growing. Unlike spores, which can germinate in many different conditions, seeds remain dormant until conditions are ideal to grow.
To initiate germination seeds must be scarified, which allows water and air to penetrate the hard or impermeable seed coat. Seeds may be scarified naturally by rodents chewing on them, rubbing against rocks or other surfaces, freezing and thawing of surface water or even passing through an animal’s digestive system.
Seeds come in a variety of shapes, sizes and colors. Some are round (like beans), ellipsoid, or globose. Others are long and pointed (like larkspur seeds). Some have wings to help them travel on the wind. The seed coats can be smooth or rough (like conkers), shiny or dull, and striped with parallel lines or ridges. Some seeds are dispersed by birds, mammals and insects. Some are adapted to catch on hair or fur so they can be carried away for miles and then dropped in a new place where they can grow.
What are seeds used for?
Seeds are packed with a wealth of nutrients and health benefits, many of which can reduce the risk of certain health conditions. From chia seeds to flaxseeds, sunflower seeds to sesame seeds, each variety brings its own unique blend of nourishing properties.
Whether sprinkled over soups, salads and grain bowls or used in homemade breads and cookies, they provide plant-based iron, magnesium, potassium, zinc and a range of vitamins and minerals. They also have gut-friendly soluble fibre and plant-based omega-3 fats, plus they’re an excellent source of protein, calcium and antioxidant polyphenols.
Seeds are classified into groups based on their botanical families; grains (cereals) and legumes (pulses) belong to the Poaceae and Fabaceae families, respectively, while nuts, pseudocereals and spices (cumin, coriander, cinnamon, fennel, mustard, nutmeg, etc.) are part of the Fabaceae family. Many cooking oils are made from seeds, too. These include olive, rapeseed (used to make canola oil) and peanut. Seeds are also a key ingredient in many tahini pastes and spreads.