What is the Centennial Ruby Hydrangea?
The Centennial Ruby Hydrangea is the showstopper of the season. In spring 2026, Monrovia released the beautiful & elegant Centennial Ruby Hydrangea to celebrate its 100th year.
cultivated about 10,000 limited-edition Centennial Ruby hydrangeas. The first 5,000 plants produced feature a special numbered commemorative metal tag, making them a unique keepsake for gardeners. I bought two hydrangeas and they are numbers 4106 and 0600!
he Centennial Ruby Hydrangea (Hydrangea macrophylla ‘Hokocentennial’) is a bigleaf hydrangea that is both compact and sturdy. It features strong stems and lush green foliage that support its abundant blooms. Its vibrant ruby-red mophead flowers intensify in color as they mature, often developing dramatic, near-black tones. This reblooming, deciduous variety provides lasting beauty throughout the growing season.
Centennial Ruby Hydrangea Zone: 4-9
The Centennial Ruby Hydrangea zone is recommended for USDA Hardiness regions 4–9. That means it will grow well from Michigan down through northern Florida.
Where to Plant The Centennial Ruby
The Centennial Ruby Monrovia Hydrangea performs best in locations that receive filtered sun, partial sun, or partial shade. This compact bigleaf hydrangea is an excellent choice for garden borders, foundation plantings, and mixed shrub beds where its rich ruby-red blooms can be appreciated throughout the growing season. Its smaller size also makes it a great option for container gardening, allowing gardeners to add vibrant color to patios, porches, and outdoor living spaces. I planted two Centennial Ruby Hydrangeas in containers this season and look forward to enjoying their stunning blooms when I step out my front door. I love the way that they look in the terracotta pots I bought for them!
Centennial Ruby Hydrangea Care
For the healthiest growth and best flowering performance, plant the Centennial Ruby Hydrangea in enriched, well-drained soil that remains consistently moist but never soggy. Apply a layer of mulch around the base of the plant to help conserve soil moisture and provide protection during harsh winters. Water deeply and regularly during the first growing season to establish a strong root system. Once established, water as needed to maintain evenly moist soil, especially during hot or dry periods. Feed with a balanced fertilizer in early spring to encourage vigorous growth and abundant blooms. Remove spent flowers by deadheading throughout the season, and prune away any dead, damaged, or weak stems as needed to maintain the plant’s appearance and health.
Fertilization Tips
The Monrovia Centennial Ruby Hydrangea does not require heavy fertilization, and actually prefers light fertilization to encourage healthy growth and beautiful flowers. The best time to fertilize the Centennial Ruby Hydrangea is in early spring. Apply a balanced, slow-release fertilizer or a layer of rich compost around the base of the plant. It is best to avoid fertilizers that are high in nitrogen, which encourages leafy growth instead of flowers. A light second feeding in late spring can be beneficial, but stop fertilizing by the midsummer months so the plant can prepare itself for dormancy. Consistently moist, organic rich soil will allow the Centennial Ruby Hydrangea to thrive in your garden.
With its compact shape and vibrant blooms, the Centennial Ruby Hydrangea is an excellent choice to add to your garden! It has made a beautiful addition to my cottage garden, and I look forward to seeing how they grow and mature in the coming years. To keep up with my gardening endeavors, and for more educational gardening content, check out my Ask A Master Gardener series.