What are short-day plants?

Short-day plants are plants that grow and bloom when the days get shorter.

Imagine you have a favorite toy that only works when it’s nighttime, like a flashlight you turn on after dinner. Short-day plants are kind of like that toy, but for nature! They start growing flowers or changing color when the days become shorter, usually in the fall.

How they know when to bloom

Short-day plants use the length of the day to tell them when it's time to bloom. If the night is long enough, say, more than 12 hours, they get a signal that it’s time to grow flowers or change colors. It’s like they’re counting how many hours of daylight there are each day.

A real-life example

A good example of a short-day plant is the chrysanthemum (or "mum"). You might see them blooming in the fall, when the days start getting shorter and the nights get longer. Mums wait patiently until the days shrink before they burst into color, just like your toy waits for night to come on!

So next time you see a big, bright mum in the garden, remember: it’s waiting for shorter days to show off its pretty flowers!

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Examples

  1. Cherry trees bloom in spring because they need long nights to start growing.
  2. Some flowers only open when the days are short and the nights are long.
  3. A gardener notices that certain plants flower every winter but not during summer.

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