Type: Creeping marsh plant
Maximum height: 20 cm.
Maximum depth: 10 cm.
Flower type and colour: Yellow flowers
Flowering: Abundant
Introduction and Origins
Cotula coronopifolia, commonly known as ‘Golden Buttons’, is a perennial plant belonging to the Asteraceae family. Native to the coastal regions of South Africa (Cape Province), this plant has successfully naturalised in many parts of the world, from the coasts of Australia to those of America and Europe, thanks to its extraordinary ability to adapt to salty environments and wetlands.
Characteristics and Habit
It is a creeping, prostrate plant with fleshy stems that tend to root easily at the nodes where they come into contact with the ground or water. Its bright green, slightly succulent leaves give off a distinctive aroma when rubbed. The flowers are the real star of the show: small, globular flower heads of a vibrant yellow that bloom tirelessly from spring through to autumn, creating a golden carpet on the water’s surface or along the edges of the pond.
Role in the Pond: Aesthetics and Phytoremediation
Cotula coronopifolia is not just an ornamental plant. Thanks to its rapid growth and dense root system, it is an excellent ally for phytoremediation. The roots actively absorb excess nutrients (such as nitrates and phosphates), helping to limit algal growth and keep the water cleaner and healthier. It is suitable for any setting: from large natural ponds to small terrace ponds (miniponds), where it can be easily grown even in just a few centimetres of water.
Care and Maintenance
Given its vigorous nature and ability to spread rapidly, it is advisable to monitor its growth and prune it periodically to prevent it from becoming too invasive towards other, less competitive species.
Cold Hardiness and Overwintering
As a plant of tropical origin, Cotula coronopifolia is sensitive to cold temperatures. In northern Italy or where winters are particularly harsh, the plant may die back. However, reviving it the following season is very simple:
- Winter storage: In autumn, take a small cutting and place it in a pot of water in a frost-free spot (a cold frame or a sunny windowsill).
- Seed collection: The plant produces a large quantity of seeds. Collect them at the end of the season to sow them again in spring; Cotula grows very quickly from seed, flowering again in a short time.
Planting tips:
- Position: Full sun or partial shade.
- Depth: 0–10 cm (moist soil or shallow water).
- Use: Borders, transition zones, phytoremediation in mini-ponds.
