Blue Nikko Hydrangea



Blue Nikko Hydrangea is a stunning flowering shrub that captivates with its beautiful blue blooms. It is a cultivar of the Hydrangea macrophylla species, native to Japan. This hydrangea variety is known for its large, mophead-like flower clusters that emerge in shades of vibrant blue, creating a striking display in gardens and landscapes.

Plant Characteristics

Blue Nikko Hydrangea is a deciduous shrub with large, serrated leaves. The most distinctive feature is its flower clusters, which consist of numerous small, fertile flowers surrounded by larger, showy sterile flowers. The color of the blooms can range from sky blue to deep indigo, depending on the soil acidity.

Ideal Growing Conditions

Blue Nikko Hydrangea thrives in partial shade to filtered sunlight. It prefers well-drained soil that is rich in organic matter. The flower color is influenced by soil acidity, with more acidic soil producing blue blooms and alkaline soil resulting in pink or purple tones.

Planting Guide

Plant Blue Nikko Hydrangea in spring or fall when the weather is mild. Dig a hole that is wider and slightly shallower than the root ball. Place the plant in the hole, ensuring it is level with or slightly above the soil surface. Backfill with soil and gently firm it around the base of the plant. Apply a layer of mulch to conserve moisture and suppress weed growth.

Watering and Fertilizing

Keep the soil consistently moist, especially during hot and dry periods. Water deeply and regularly, ensuring the root zone is adequately hydrated. Avoid overwatering, as it may lead to root rot. Apply a balanced slow-release fertilizer formulated for hydrangeas in early spring and again in early summer.

Pruning and Maintenance

Prune Blue Nikko Hydrangea in late winter or early spring to remove any dead or damaged branches and shape the plant. You can also selectively prune to control the size and promote better airflow. Regularly monitor for pests, such as aphids or spider mites, and take appropriate measures to address them.

Harvesting or Flowering

Blue Nikko Hydrangea typically blooms from early to late summer, delighting with its abundant blue flowers. Enjoy the beautiful display of clustered blooms that can last for several weeks.

Post-Harvest Care

Blue Nikko Hydrangea is primarily grown for its ornamental value and is not typically harvested. After the blooming period, allow the flowers to naturally fade and remain on the plant, as they can provide winter interest. Continue regular care, including watering, fertilizing, and monitoring for any signs of pests or diseases.


Blue Nikko Hydrangea is generally a resilient plant, but it can encounter issues such as powdery mildew or root rot in overly wet conditions. Proper spacing, good air circulation, and watering at the base of the plant can help prevent these problems. If necessary, treat with appropriate fungicides or consult a gardening professional.

Fun Facts

The blue color of the Blue Nikko Hydrangea blooms is influenced by the presence of aluminum ions in the soil. Acidic soils help the plant absorb aluminum, resulting in the characteristic blue color. These hydrangeas are also known for their ability to change flower color based on soil pH, with more alkaline soils producing pink or purple blooms.