Germination
Hidden inside every seed is a tiny embryonic plant complete with root, stem and leaves, ready to sprout when suitable conditions appear. The seed's plant-parts are not 'true' leaves, stem and roots, but are effective enough to launch the plant into its growth phase when true leaves, roots and stems appear. Flowering plants whose seeds have one embryonic leaf (cotyledon) are called monocotyledons. Flowering plants whose seeds have two cotyledons are called dicotyledons or dicots. Tomato plants are dicots.
When warmth, water, and oxygen become available a seed begins to germinate. The embryonic plant begins to grow and the seed coat swells and breaks open under the pressure of the growing seedling within the seed coat. As long as the environmental conditions remain favourable the plant will continue to grow, the stem and the cotyledon(s) pushing upwards and the root(s) extending downwards.
As the emerging seedling begins to grow, its dependence on stored food diminishes and the transition to its own photosynthetic food production begins. It will not survive unless ample light is added to the water, warmth, and oxygen needed for germination.
Definition
A seed can be considered to have successfully germinated when two (2) distinctly separate cotyledons (embryonic leaves) can be seen. This process will usually take place between 5 and 20 days depending upon local conditions.
Each seed produces only ONE stem. If more than one stem appears in a peat pot, it indicates that multiple seeds have been planted.
In some cases the seed coat itself will be pushed upwards as it adheres to a cotyledon like a small helmet.
Tomatosphere is sponsored by Agriculture and Agri-Food Canada, the Canadian Space Agency, Heinz Canada, H.J. Heinz Company Foundation, Ontario Centres of Excellence, Stokes Seeds and the University of Guelph.
