Asparagus plants are a long-term investment for any gardener, providing delicious spears for many years. When these plants start to bloom, it can sometimes cause concern for those unfamiliar with the asparagus life cycle. Understanding this natural process is important for maintaining a healthy and productive asparagus patch.
What is Asparagus Bloom
Asparagus plants produce small, yellowish-green, bell-shaped flowers that emerge from the feathery, fern-like foliage. This process, often called “ferning out” or “bolting,” typically occurs after the main harvest or if spears are left unharvested. The flowers are usually around 0.25 inches long, appearing singly or in clusters at leaf junctions.
Why Asparagus Blooms
Blooming is a natural progression for mature asparagus plants, part of their reproductive cycle to produce seeds. Asparagus is dioecious, with separate male and female plants; only female plants typically produce berries after flowering. Environmental factors like high temperatures, drought stress, or inconsistent watering can accelerate blooming. Unharvested spears also cause the plant to shift energy to foliage and then flowers.
Impact on Asparagus Spears
When an asparagus plant blooms, it significantly impacts spear quality. Energy is diverted from tender shoots to developing flowers and seeds, making spears woody, tough, and fibrous. Their flavor can also diminish, sometimes becoming bitter. While not harmful, these altered spears are considerably less desirable for eating. Allowing spears to fern out helps the plant store energy for future growth.
Managing Asparagus After Blooming
After blooming, allow the fern-like foliage to grow throughout summer and fall. This fern growth is crucial for photosynthesis, enabling the plant to store carbohydrates and sugars in its crowns. These stored nutrients are essential for a robust harvest the following year.
Consistent watering, especially during dry spells, supports healthy fern growth and crown development. Weeding also reduces competition for nutrients and water. In late fall or early winter, once ferns yellow and die back, cut them to the ground to prepare the bed for the next season.
Asparagus Berries and Seeds
Female asparagus plants produce small, round berries that turn bright red as they mature, each containing three or four seeds. These bright red berries are not edible for humans and are considered mildly toxic if consumed, potentially causing digestive upset. While berries are a natural means of propagation, relying on them for new plants can result in genetic variability. Growing asparagus from seed also takes significant time, often two to three years before plants are established enough for a substantial harvest.