Gardening – Seeds a life source

Seeds are packages of genetic information with instructions for building the next generation.  They are the foundation of human life, from the food that we eat to the fibres in our clothing, as well as most of the products that we use in our daily lives. 

Seeds contain a plant embryo – a small immature plant with a stem, a root structure and at least one leaf. Most seeds have their own food supply contained in the endosperm, which acts as a source of carbohydrates, vitamins, fats, antioxidants, and proteins. The endosperm supports the growth of the plant embryo until photosynthesis kicks in, while the seed coat provides protection.

Germination usually begins with a drink, and once water seeps into the seed a whole raft of metabolic processes begin – the tiny plant embryo starts to grow and the embryonic root breaks through the seed coat.

Timing is everything. Germination is influenced by environmental conditions; affected by temperature, frost, fire and daylight length. The plant will die if it germinates in the wrong season. 

Seeds cannot germinate until dormancy is broken, which requires optimal environmental cues such as the right temperature, humidity, soil pH, or a combination of cues. 

Some seeds are so specific that they require travelling through a bird’s digestive tract or must experience fire.

The health of the parent plant and environmental and soil conditions, as well as the use of herbicides during seed development, has a big impact on the longevity of the seed. Seeds are rich in antioxidants, which they make to repair damage caused by free radicals. The antioxidants  also protect against deterioration and can break dormancy or trigger germination.

Climate change will also alter seed longevity. Drought and elevated temperatures can result in seed abortion as well as altering the quality of those seeds that do stay on the parent plant. Many countries working on seed gene banks are selecting for survival under hazardous weather conditions, as well as the ravages of war.

The chemicals we use on our gardens can also have an impact on germination. For example, glyphosate wasn’t originally intended to be used as a herbicide. It was patented as a metal chelator, something that reacts with, and binds up, mineral elements. The idea was to use it for cleaning out metallic build up inside corroding pipes. Used as a herbicide, it binds up mineral elements such as copper, iron, magnesium and zinc, which of course then makes theose elements unavailable to plants and soil microbiota. Depriving plants of mineral elements central to their health has a huge impact, not only on the plant’s nutrition, but the viability of the seeds as well.