Stages of Strawberry Seed Germination
Strawberries, like other seeds, go through three basic stages to reach successful germination. They begin their lives dormant until the proper conditions are met for them to enter the second germination stage of breaking their dormancy, or becoming activated. Then they move on to the third and final stage: sprouting. Then plant the sprouted strawberries outdoors in the garden once they are strong enough and begin bearing fruit and their own seeds the following year.
The embryo inside the strawberry seed remains dormant until the tough, outer seed coat is weakened. Weakening occurs naturally when the ripe berries are eaten by an animal. The outer coating breaks down inside the stomach with the aid of the digestive fluids. The seed then passes through and out in animals' waste, which provides fertilization as the seed germinates and grows. Gardeners replicate this process by scuffing the tough outer coating with sandpaper or by soaking the seeds in warm water for 1-2 days.
Once the seed coat is weakened, the embryo within the seed begins the respiration process, where it begins absorbing oxygen from outside the seed coating. The embryo begins absorbing moisture from the surrounding air or soil. Production of the specific enzymes for growth begins and the embryo begins forming into a seedling. The seedling begins to swell and grow, producing first a root, then later the sprout that will emerge from the soil.
Germination until sprouting takes between 7 and 21 days for strawberries. The first leaves visible are the rounded leaves used to break through the seed coating and soil. They absorb light and oxygen from the air while the first true strawberry leaves begin to form. Most seedlings are considered viable once two sets of true leaves have formed on the stem.
Strawberries are cold germination plants. They require a minimum of a 2-week period of freezing temperatures followed by cool temperatures in order to break dormancy. The seeds require temperatures between 40 and 60 degrees Fahrenheit in order to germinate. Light requirement are minimal until the seedling emerges from the soil, then full sunshine is required for it to thrive. The seed must remain moist for the entire period of germination or the embryo will dye of thirst once dormancy is broken.