Life

The Casual Gardener: Julie Thompson-Adolf's tips for sowing the seeds of success

They come in many shapes and sizes but each viable seed contains a magic formula. In this extract from Starting and Saving Seeds author Julie Thompson-Adolf looks at where plant life begins

Every seed is waiting for the right conditions to grow. Picture by Libby Williams
Every seed is waiting for the right conditions to grow. Picture by Libby Williams Every seed is waiting for the right conditions to grow. Picture by Libby Williams

WHEN you open a seed packet and spill out its contents, what do you see? From tiny, sand-like grains of poppy seeds to oblong, at pumpkin seeds, what you’re really looking at is potential.

No matter the size or shape, inside every seed is a living plant just waiting to spring into action. Sure, it’s embryonic, but the life within a seed possesses all the necessary elements to grow into a strong, beautiful, productive plant. It’s simply waiting for the right conditions to realise its potential.

Until the environment presents the perfect factors, the future plant within a seed behaves as plants do. It carries on respiration, absorbing oxygen and releasing carbon dioxide. It takes in water from the air, allowing it to convert stored carbohydrates into food. It thrives within its seed coat until the conditions are perfect for it to realise its promise – and germinate.

Every seed is alive, waiting for the right conditions to grow. Most seeds fall into the dicot category, which have two cotyledon, but seeds in the grass family are monocots.

Now, let’s think back to the good old days when we tried desperately to stay awake in biology class. (I know my 14-year-old self never imagined I’d actually need and use this information one day.) Remember those lessons about cotyledons, dicots, and monocots? Well, now you can see them in action.

Inside the seed case, you’ll find cotyledons, also known as the seed leaves. A cotyledon attaches to the root tip and surrounds the tiny leaf bud. The cotyledon functions to absorb and, in some cases, store food for the embryo produced from the surrounding starchy tissue. All seeds, regardless of size or shape, contain a cotyledon (one or two), stem, leafy bud, and root tip.

Monocots contain one cotyledon. Think of plants in the grass family (Gramineae), like cereal crops. In most of these plants, food is stored in the seed at the time of germination, and the single cotyledon continues to absorb nutrients and pass them on to the rest of the seedling until it can photosynthesise.

Dicots possess two cotyledons. In most dicots, which include vegetable seedlings and flowering plants, the cotyledons absorb all the nutrients in the seed by the time germination occurs. Some cotyledons continue to feed the seedling until it can photosynthesise; then they shrivel and drop off.

Others turn green and start to photosynthesise themselves. This is why teachers use beans in experiments. Beans provide the perfect examples of dicots with their two, relatively large cotyledons wrapped around the tiny embryo.

The cotyledons make a great show as they unfurl during germination, much to the wonder of children. In some seeds, the stored food source isn’t the cotyledon. Instead, a layer called the endosperm surrounds the embryo, feeding the seed. From the time it matures on the parent plant until it breaks dormancy in the next growing season, the endosperm provides sustenance for the seed.

In certain cases, such as sweet corn, the endosperm is the food we humans enjoy from the plant. Just make sure to set aside some seeds to grow the next season! The perfect little powerhouse package that will eventually become a fabulous flower or tasty tomato remains dormant, biding its time, until conditions are ideal for it to break dormancy.

Most seeds fall into the dicot category, which have two cotyledon, but seeds in the grass family are monocots. A seed is a ripened, fertilised ovule containing an embryonic plant and a supply of stored food, all wrapped in a seed coat. Many “seeds” are actually fruits—the mature ovary of a ower containing one or more seeds. A kernel of corn is an example of a seedlike fruit. Black, white, tiny, large, colorful... seeds are nature’s artwork, packed with goodness inside.

:: Starting and Saving Seeds by Julie Thompson-Adolf is published by Cool Springs Press.