The flowers, planted in long strips opposite the Vietnam Post building near Hoa Phong Tower, have attracted visitors from early morning, with many stopping to take photographs against the purple and pink blooms.
The Japanese violet, also known locally as ngoc han, produces clusters of small purple and pink flowers.
The plant thrives in sunlight and well-drained soil, making it suitable for landscaped areas around the lake.
On October 2, many young women wearing ao dai, dresses and other outfits gathered at the flower beds for photographs. Some visitors waited about 15 minutes for a preferred photo spot despite temperatures reaching 34 degrees Celsius.
Phuong Thao, 23, from Long Bien, said she was surprised by the number of visitors but was pleased with the photographs she took after waiting for a suitable spot.
The flowers have also attracted couples, while photographers have begun offering services in the area, typically charging VND 10,000-50,000 per photo.
Foreign tourists have also stopped to photograph the blooms. A visitor from Australia, said she was impressed by the lively atmosphere and scenery around the lake.
Landscaping workers regularly inspect the flower beds and replace damaged or wilted plants to keep the display fresh.
The flower beds form part of Hanoi's efforts to improve public spaces and urban landscaping, including investment in parks, gardens and green areas.
