Blue hydrangeas are indeed a marvelous spectacle in gardens. Their rarity in the blue hue makes them a favorite among gardening enthusiasts. In this comparison, we’ll explore two exquisite varieties of blue hydrangeas: Nikko Blue and Endless Summer.
The primary distinction between the Nikko Blue Hydrangea and the Endless Summer Hydrangea lies in their blooming patterns. The Nikko Blue flourishes exclusively on old wood, meaning it produces flowers only on the growth from previous years. On the other hand, the Endless Summer Hydrangea shows a more versatile blooming habit, as it can produce flowers on both new and old growth.
Additionally, when it comes to the intensity of the blue color, Nikko Blue Hydrangea exhibits a deeper and more vibrant blue compared to the Endless Summer variety.
Nikko Blue Hydrangea and Endless Summer Hydrangea
| Nikko Blue | Endless Summer | |
| Hardiness zone | 6-9 | 4-9 |
| Mature height | 5-6′ (1.5-1.8m) | 3-5′ (0.9-1.5 m) |
| Mature width | 6-8′ (1.8-2.4m) | 3-5′ (0.9-1.5 m) |
| Growth rate | fast | fast |
| Light exposure | partial shade | partial shade |
| Soil | moist, drained | moist, drained |
| Soil pH | 6.0-7.0 | 6.0-7.0 |
| Watering | 1-2 times per week in a drought | 1-2 times per week in a drought |
| Diseases | fungus | fungus |
| Pests | insects, mites | insects, mites |
Nikko Blue is more blue
Nikko Blue is renowned for its strikingly deep blue hue, boasting high color intensity. In contrast, the Endless Summer Original presents a more subdued color palette. Its blossoms are characterized by a lighter, paler shade, often displaying a subtle light purple tint.
Observations by numerous gardeners reveal that Nikko Blue typically produces a slightly greater number of inflorescences during its flowering season. This attribute contributes to its slightly more impressive and magnificent appearance when compared to Endless Summer Original.
Nikko Blue blooms only on old growth
A notable advantage of the Endless Summer hydrangea is its ability to flower on both old and new growth. Prior to the development of this variety, hydrangeas typically bloomed exclusively on either new or old growth.
The efforts of breeders have enabled Endless Summer and similar varieties to produce inflorescences on both the current year’s growth and the branches from the previous year.
Conversely, the Nikko Blue hydrangea blooms solely on the mature growth from the previous year. This characteristic is seen as a limitation because it means the plant cannot be pruned back completely without risking the loss of its flowers.
For Nikko Blue, the recommended pruning method is to trim it right after it flowers, focusing on removing only the faded inflorescences.
On the other hand, the Endless Summer hydrangea offers more flexibility in pruning. It can be cut back to ground level in spring, and it will still produce new shoots and bloom within the same year.
Endless Summer blooms longer
Nikko Blue typically enjoys a flowering period of around two months. The onset of its blooming phase can vary, starting either in late spring or early summer, depending on the climate. This variety continues to bloom until mid-summer, but beyond this period, it does not produce more flowers.
In contrast, Endless Summer also blooms for approximately two months on its old wood. However, as early summer arrives, it begins to grow new shoots, leading to a second blooming phase. This characteristic extends its flowering period throughout the entire summer.
In regions with warmer climates, the Endless Summer hydrangea may start blooming earlier and continue until October. Moreover, this variety responds well to pruning; cutting the faded flowers can encourage the growth of new blooms.
Therefore, for those seeking the longest possible flowering period, the Endless Summer Original is the ideal choice.
Endless Summer is more frost resistant
Endless Summer is more adaptable to varying climatic conditions, capable of thriving in USDA hardiness zones 4-9. This range indicates a higher tolerance to different weather conditions, particularly to lower temperatures.
On the other hand, Nikko Blue is less hardy and is suitable for growing in USDA hardiness zones 6-9. This limitation means it’s less adaptable to colder climates compared to Endless Summer.
The superior frost resistance of Endless Summer makes it a more accessible option for a wider range of gardeners, especially those in cooler regions.
However, the frost hardiness of Nikko Blue can be enhanced through additional measures. By covering it with frost protection material during winter, gardeners can cultivate this variety in colder conditions, although this approach entails extra cost and effort.
Nikko Blue is bigger
Overall, Nikko Blue tends to be larger compared to Endless Summer. It can grow up to 5-6 feet (1.5-1.8 meters) tall and 6-8 feet (1.8-2.4 meters) wide. Additionally, this variety exhibits more vigorous growth, allowing it to reach its maximum size more rapidly.
In contrast, the Endless Summer Original is more compact in size. It typically reaches heights of 3-5 feet (0.9-1.5 meters) and spreads to a similar width. Many gardeners observe that it grows at a slightly slower rate than Nikko Blue.
There is also a subtle difference in their shapes. Nikko Blue has an elongated or oval shape, whereas Endless Summer tends to have a more spherical form.
Therefore, for gardeners with ample space who wish to fill it quickly, Nikko Blue is the preferable choice. However, if a more compact hydrangea is desired, then Endless Summer Original would be the ideal selection.