Short Day Plant
Definition - What does Short Day Plant mean?
A short-day plant is a plant that requires a lot of darkness and performs best with shortened hours of sunlight. Many spring and bulb-bearing plants would be examples of short-day plants.
In contrast to short-day plants, there are also long-day plants, as well as day-neutral plants.
MaximumYield explains Short Day Plant
A short-day plant is one that requires less than 12 hours of light to thrive and grow. Because of the shorter daylight hours of the early season, this would include all early spring bloomers and bulb-bearing plants.
Long-day plants would include the summer bloomers like hydrangea or spirea and many vegetables, because, in order to thrive, bloom, or bear fruit, they require a much longer period of daylight than darkness.
The amount of daylight a plant requires to bloom is called “photoperiodism” and it is what determines whether a plant is a short-day or long-day variety. For horticulturists, understanding the process photoperiodism is at the core of understanding the flowering process.
Potted short day plants can be “forced” to bloom by regulating the amount of daylight or darkness a plant receives. A potted tulip, for example, will spend more than 12 hours a day in total darkness and then be brought outside to be exposed to natural light for only a few short hours. This will stimulate the formation of bloom buds on the plant and cause it to bloom earlier or later than it naturally would. Christmas cactus, poinsettias, and bulb bearing plants sold commercially have been forced into blooming at a specific time using this practice.