Plant Propagation Technique
Seeds are fertilized, ripened ovules or "eggs" of flowering plants. Each contains a rudimentary plant (the embryo) which while dormant is protected by various coats and is supplied, either in or around its seed leaves (cotyledons), with stored-up food sufficient to start its active life and carry the seedling until its roots and true leaves begin to function.
Since seed development results from the fertilzation of the ovules by pollen produced in the stamens of the same or some other flower, reproduction of plants by seed is termed "sexual" as distinguished from the "asexual" processes of division, rooting cuttings, etc.
The popular idea is that seed germination or sprouting is the first step in plant growth; actually it is merely the resumption of activity by the dormant young plant in the seed. The factors essential to germination are: viable seed, moisture, air and favorable temperature. The degrees of the last three factors needed vary considerably with different kinds of plants.
Briefly, the process of germination is as follows: The seed absorbs water which enables certain substances in the seed (called enzymes) to convert stored starches into sugars. These contribute to the growth of the plant cells and tissues; this increases the size of the embryo, which, becoming active, bursts through the water-softened seed coats - and a seedling plant is started on its way.