Germination: Seed Dormancy

Well-timed germination is essential to grow wildflower seeds successfully. A main factor that contributes to poor or erratic germination is seed dormancy. Seed dormancy is the state in which seed is unable to germinate, even under ideal growing conditions (Merriam-Webster). Because dormancy can be broken by most ideal growing conditions (different and specific for each species), the seeds germinate when they are the most likely to flourish.

Species that have dormant seed have evolved dormancy because it is useful in survival. Plants utilize dormancy so that seed can endure unfavorable conditions and not all germinate at the same time and are killed by unfavorable weather (Seed Dormancy). While dormancy can enhance plant survival in the wild, it can prevent seeds from germinating uniformly and growing well in wildflower seed production fields.

There are two different categories of seed dormancy: exogenous and endogenous (Scarification). Exogenous dormancy is caused by conditions outside of the seed’s embryo. An example of exogenous dormancy is when the seed coat is too durable for moisture to infiltrate, effectively preventing germination. Endogenous dormancy occurs due to chemical changes within the seed’s embryo. One reason a plant cannot germinate due to endogenous dormancy is because the embryo is not yet fully developed or specific seasonal cues have not ensued (Endogenous Dormancy). Germination could also be suppressed due to endogenous chemical inhibitors.