Why Is Germination Taking So Long?
We’ve been hearing from some growers that reliable germinators are taking longer than usual to sprout. One of our growers planted tomato seeds under optimal conditions and, rather than sprouting in 5–14 days as expected, they took 4½ weeks, still with 90% germination.
This germination delay is called dormancy, a state in which a seed is unable to germinate despite optimal conditions. Dormancy is a natural survival strategy of many species. Instead of germinating all at once, seeds sprout over weeks, months, or even years—this reduces risk of a whole population succumbing to a single unfavorable weather event, like a late frost or a spring drought, thereby increasing the success of the species as a whole.
Why is seed dormancy showing up in plants that were previously so reliable? One theory points to the erratic weather patterns and increasing temperature of the changing climate. When unusual weather conditions coincide with seed development in the mother plant, the seeds can be affected. If the mother plant undergoes stress while growing seed, the resulting seeds can have higher rates of dormancy and decreased vigor. Cooler-weather crops seem to be most susceptible to these issues as temperatures increase. However, as with the tomato seed example, warm-weather crops are not immune.
Although dormancy as a survival mechanism is not a bad thing for the plant, it can be frustrating for growers who plan their seeding schedule to take optimal advantage of their growing season, especially for those of us with shorter northern seasons. This trend is just starting to be studied, and many questions remain unanswered. As with all things in the garden (or life!), it is wise to practice patience and leave room for the unexpected. Don’t dump those seed trays yet!
Want to learn more? Check out Seed Saving for Beginners, which includes: