Flowering takes place in May and June. Large, spherical flower heads appear on tall, sturdy stems, consisting of hundreds of small, star-shaped flowers in pure white. Together, these flowers form a sleek and symmetrical flower head that contrasts beautifully with the fresh green foliage of surrounding plants. The bright white color gives borders a fresh, light, and elegant character and combines particularly well with dark-foliage plants or deep-colored perennials. The flower heads retain their ornamental value even after flowering. When they dry out, the spheres remain decorative for a long time and provide structure in the garden.

Allium 'Mont Blanc' grows best in a sunny location in well-drained soil, but also tolerates light partial shade. The bulbs are planted about 15 centimeters deep with a spacing of approximately 25 centimeters between them. For a rich flowering effect, an average of twenty bulbs per square meter is recommended. As with many ornamental onions, the foliage often partially dies back during flowering. Therefore, it is recommended to combine the plants with perennials that can conceal the dying foliage.

This ornamental onion is fragrant, but it attracts plenty of bees and butterflies, thereby contributing to a biodiverse garden. Furthermore, the plant is highly resistant to deer and rodents. Allium 'Mont Blanc' is also very suitable as a cut flower and is frequently used in bouquets due to its elegant shape and long vase life. With its pure white flowers, impressive height, and stylish appearance, this ornamental onion is a timeless addition to any garden.