Growth Stages of Blueberry Flowers
Healthy blueberry bushes grow thousands of blooms every blueberry season. Each of the blueberry buds can produce 16 flowers that will, hopefully turn into berries. Below are the stages that every blueberry bud goes through on its road to producing berries:
- Tight dormant buds – At this stage, the flower bud hasn’t started to swell. It is closed tightly.
- Bud scales swell – The bud starts to swell in the spring and the outer bulb starts separating at the tip. At this stage, the bud tolerates the cold from 10° (-12°C) to 15°F (-9°C).
- Flower buds expand – At this point, the flower buds open, and you can see the flowers between the bud scales. These buds are more susceptible to cold. They need temperatures of 20°F (-7°C) to survive.
- Tight cluster formation – Blueberry flower clusters form at this stage, and you can recognize the blooms in the cluster. The clusters need temperatures between 20°F (-7°C) to 23°F (-5°C) for survival.
- Early pink buds – You can see the flowers at this point. They exhibit pink corolla petals that are closed and short. The temperature the blossoms need now are from 23°F (-5°C) to 25°F (-4°C).
- Late pink buds – Each of the blueberry flowers is fully developed at this stage. The petals are longer and have turned white. The blooms are still closed. The temperature required for the buds range from 24°F (-4.4°C) to 27°F (-2.8°C).
- Early blooms – A few of the petals open at this stage but many of them remain closed. As the flowers open, they need higher temperatures from 25°F (-4°C) to 28°F (-2.2°C).
- Full blooms – Almost all the flowers are open, and they need temperatures of at least 28°F (-2.2°C).
- Petals fall – The flower petals begin dropping off the blueberry bush. After they fall, you can see small, green berries. The berries need the temperature to be at least 32°F (0°C) to prevent frost injury.
After the last petal fall stage, the green blueberries grow larger. As they grow, the berries become a lighter green color, which eventually takes on a reddish tinge. The largest berries turn blue first, and they begin to soften. You can begin picking the blueberries when 10 percent of them are ripe. This is the preharvest time. After picking the berries two to five times, over 75 percent of the berries have turned blue.