Ornamental Plants Can Help Clean Waterways, Miami Study Finds.
In a new study conducted in Miami, ornamental plants have proven to be more than just decorative – they can also help tackle water pollution. The research found that large African marigold plants were particularly effective in removing harmful nutrients from polluted canals, offering a potential solution to cleaning waterways contaminated by farm runoff.
Fertilizers and manure from farms often contain high levels of phosphorus, nitrogen, and other nutrients. When these substances are washed into rivers and canals by rain, they create ideal conditions for algae to flourish. Algal blooms can deprive water of oxygen, endangering fish populations and disrupting ecosystems.
Inspired by the floating farms of the ancient Aztecs, Miami scientists decided to experiment with using ornamental plants to cleanse the water. They placed different types of flowering plants on inexpensive floating mats and allowed them to grow in the polluted canals for 12 weeks. Of all the plants tested, the large African marigold showed the best results, removing 52% more phosphorus and 36% more nitrogen than the natural nutrient cycling in untreated water.
Researchers are now testing other ornamental plants to see if they also offer similar benefits for water filtration.
Interestingly, while filtering out the pollution, the marigolds produced high-quality blooms, comparable to those grown on commercial flower farms. The plan is to eventually harvest and sell these flowers as a way to help finance future water cleanup efforts.