Seed Mortality

In nature, a lot of plants will produce huge amounts of seeds to ensure success in the survival of their species. A great number of seeds will not make it through the two critical phases of their life -- the Germination and Establishment phase.

Seed mortality may occur for various reasons. The temperature can affect seed germination rates and success. Some seeds may require heat while others may benefit more from being soaked in water for a period of time. Please research your plant type to learn more about it's specific germination requirements.


Seed Dormancy

While a seasoned or even new Gardeners may provide an ideal environment to induce germination, some seeds may still not sprout into little seedlings. In such cases, the seeds are considered to be dormant or not active but capable of becoming active. A process called stratification may be required to facilitate germination. Stratification may include placing seeds in damp sand, sawdust or peat moss in order to promote the germination process.

Additionally, Common vegetable garden seeds do not have dormancy and are usually ready to germinate immediately while seeds from the "wild" posses high dormant traits. Some seeds may be unable to germinate after two weeks while others, like the certain species of the louts plant may be stored for up to 2,000 years. In fact, the oldest seed known to germinate is a 1,300 years old lotus fruit plant that was recovered from the dry lake-bed in Northeastern China.


The Shell (Coat)

The embryo in the seeds' core requires moisture to activate its metabolism to start the germination process. If the seed's coat is dense and thick, this may prevent any water or moisture to reach the embryo. One example of a plant producing seeds with very thick coating is the Kentucky Coffee Tree. It's not uncommon for the Kentucky Coffee Tree to produce seeds with a coat that's up to 2 millimeters thick.

A process called scarification may be required to kick start germination. In a botanical context, scarification is the act of scarring or nicking the seed's coat.



source : hydroponic