Germination, the sprouting of a seed, spore, or other reproductive body, usually after a period of dormancy. The absorption of water, the passage of time, chilling, warming, oxygen availability, and light exposure may all operate in initiating the process.
Active growth in the embryo, other than swelling resulting from imbibition, usually begins with the emergence of the primary root, known as the radicle, from the seed, although in some species (e.g., the coconut) the shoot, or plumule, emerges first. Early growth is dependent mainly upon cell expansion, but within a short time cell division begins in the radicle and young shoot, and thereafter growth and further organ formation (organogenesis) are based upon the usual combination of increase in cell number and enlargement of individual cells.
In the process of seed germination, water is absorbed by the embryo, which results in the rehydration and expansion of the cells. Shortly after the beginning of water uptake, or imbibition, the rate of respiration increases, and various metabolic processes, suspended or much reduced during dormancy, resume. These events are associated with structural changes in the organelles (membranous bodies concerned with metabolism), in the cells of the embryo.
Until it becomes nutritionally self-supporting, the seedling depends upon reserves provided by the parent sporophyte. In angiosperms these reserves are found in the endosperm, in residual tissues of the ovule, or in the body of the embryo, usually in the cotyledons. In gymnosperms food materials are contained mainly in the female gametophyte. Since reserve materials are partly in insoluble form—as starch grains, protein granules, lipid droplets, and the like—much of the early metabolism of the seedling is concerned with mobilizing these materials and delivering, or translocating, the products to active areas. Reserves outside the embryo are digested by enzymes secreted by the embryo and, in some instances, also by special cells of the endosperm.
Environmental factors play an important part not only in determining the orientation of the seedling during its establishment as a rooted plant but also in controlling some aspects of its development. The response of the seedling to gravity is important. The radicle, which normally grows downward into the soil, is said to be positively geotropic. The young shoot, or plumule, is said to be negatively geotropic because it moves away from the soil; it rises by the extension of either the hypocotyl, the region between the radicle and the cotyledons, or the epicotyl, the segment above the level of the cotyledons. If the hypocotyl is extended, the cotyledons are carried out of the soil. If the epicotyl elongates, the cotyledons remain in the soil.
I had pepper seeds that were several years old. I hated to throw the package away without checking to see if they were still good. I checked the viability of the seeds by doing a seed germination test.
Step 6: Check seeds daily. Examine your seeds each day for germination and to make sure the towel stays damp. Spray the towel if needed.
Benefits of Pre-Sprouting Seeds
After experiencing how easy it was to see which seeds germinated using paper towels, I decided to pre-sprout more of my indoor seedlings. I routinely pre-germinate tomatoes, peppers, eggplants, Swiss chard, melons, cucumber, squash, cilantro, spinach, and kale.
Step 8: Keep your seedlings warm and moist. Use your spray bottle to keep the soil surface moist and continue caring for your seedlings as described from step 5 on in this article: 10 Steps to Starting Seedlings Indoors.
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Scarify the seeds right before you plant them. You don’t want to leave the scarred seeds out where bacteria might enter.
After germination takes place, the best temperature for growing seedlings is about 10 degrees cooler than the temperature in which they germinated.
Make sure you don’t expose to your seeds to temperatures higher than 90 degrees Fahrenheit. Those temperatures will kill the embryo inside of the seed, rendering it useless.
What Do Seeds Need to Germinate?
Always plant seeds at a depth of 1-2 seed sizes. So, the bigger the seed, the deeper you need to plant them.
Some seeds that need cold treatment also can be planted outdoors in the fall or stored in the refrigerator throughout the fall and winter. Then, in the spring, you plant the seeds in pots.
Start checking the seeds daily. Depending on the type of seeds you’re germinating, some only take one or two days to sprout. The fastest germinating seeds are:
Some species of plants, such as begonias and coleus, need light to germinate, but if you’re germinating vegetable seeds, don’t worry about providing lights.