Nikko Blue Hydrangea vs Endless Summer: Which One Is Best?


Blue hydrangeas are a fantastic sight. This color is most popular among gardeners because not many plants bloom blue. Also, the hydrangea inflorescences are large, and this makes them even more attractive.

There are some blue varieties among the hydrangeas, but the most popular are Endless Summer and Nikko Blue, and today we will talk about them.

The Endless Summer series appeared in 2004 at Bailey Nurseries and quickly won the hearts of many gardeners. There are several varieties in this series, but only the Endless Summer Original is blue.

Japanese breeders bred Nikko Blue, but it spread wide when it got to the United States. Now it is one of the most popular varieties of Bigleaf hydrangea.

The difference between these varieties is quite significant. So to find out which one is best for you, we need to dig a little deeper, so let’s go!

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 Hydrangea and Endless Summer Hydrangea
Nikko Blue Hydrangea and Endless Summer Hydrangea

The color of Nikko Blue more intense

Nikko Blue has a really blue color. Also, the color intensity is high. Under appropriate growing conditions, only a few varieties can match it.

Endless Summer Original has a less saturated color. Its flowers are lighter and pale in color. Also, this variety has a light purple hue.

Many gardeners have noticed that Nikko Blue has slightly more inflorescences in the flowering period. So it will look a little more magnificent compared to its competitor.

In terms of color, Nikko Blue looks better than Endless Summer Original. Therefore, if a bright color is important to you, then you should prefer the Japanese variety.

Looking ahead, I have to say that the Endless Summer series has one good variety, which by its color, can compete with Nikko Blue on equal terms. But we’ll talk about it later.

The two varieties that we are considering today, like many other hydrangeas, can have different shades and color intensities depending on the growing conditions.

If you plant Endless Summer Original in a place where there is enough sun (6 hours) and provide sufficient soil acidity, it will look as beautiful as Nikko Blue.

For this reason, I want to give recommendations. First of all, it is best to plant hydrangeas in a place where they will receive 6-7 hours of morning sun and in the afternoon will be in the shade. You also need to acidify the soil; aluminum sulfate copes best with this.

Nikko Blue blooms only on old growth

One of the most significant benefits of Endless Summer is flowering on old and new growth. Before the appearance of this variety, hydrangeas bloomed on either new or old growth.

Thanks to breeders’ hard work, everything has changed, and some varieties can form inflorescences on both young and last year’s branches.

Nikko Blue blooms only on last year’s mature growth, and this is its disadvantage because you can’t prune it completely; otherwise, you will lose the flowers.

In the case of Endless Summer, you can prune it to ground level in the spring, and it will grow new shoots and will still bloom this year.

Not so with Nikko Blue. It cannot be pruned to ground level at all. If you need to prune this variety, then do it immediately after flowering. It would be best if you did not prune the branches by more than a third.

Nikko Blue will form flower buds by the end of the year, and they will bloom next spring.

Endless Summer blooms longer

Nikko Blue blooms for about two months. Depending on the weather, the beginning of flowering may occur in late spring or early summer. This variety blooms until mid-summer, and that’s all; it is impossible to get more flowers from it.

Endless Summer, on the other hand, also blooms for two months on old wood. But by early summer, young growth is formed, and the hydrangea blooms again. This means that the flowering period lasts for the whole summer.

In warmer climates, Endless Summer can bloom earlier, and this can last until October. Also, if you cut the flowers as soon as they fade, it will stimulate a new flower. With proper care, the flowering period can last six months.

However, do not cut the faded flowers later than July because the hydrangea will spend too much effort on the flowers. As a result, it will be harder for her to survive the winter.

Do not prune lower than 1-2 inches from the inflorescence. Otherwise, you can damage the flower buds that will bloom next year.

If you do not prune wilted flowers at all, the plant will accumulate a lot of energy, and in the coming year, the flowers will be lusher.

So if your goal is to get the most prolonged flowering period, you should definitely choose Endless Summer Original.

Endless Summer hardier

Endless Summer can be grown in zones 4-9. This means that it tolerates a broader range of climatic conditions. This is especially true of low temperatures.

Unfortunately, Nikko Blue is not so hardy; it can be grown only from 6 to 9 hardiness zones.

So thanks to better frost resistance, Endless Summer is available to more gardeners than Nikko Blue.

You can increase the frost resistance of Nikko Blue by covering it for the winter with frost protection material. It requires extra cost and effort, but you will be able to grow this variety in colder conditions.

Nikko Blue bigger

In general, Nikko Blue is larger than its opponent. It can reach 5-6 ‘(1.5-1.8m) in height and 6-8’ (1.8-2.4m) in width. Besides, this variety grows a little more vigorously, so it will reach its maximum size faster.

Endless Summer Original is a bit more compact. This variety grows to 3-5 ‘(0.9-1.5 m) in height and as much in width. Many gardeners claim that it grows a little slower than Nikko Blue.

Also, today’s opponents differ slightly in form. Nikko Blue has an elongated (oval) shape, while Endless Summer has a spherical shape.

So if you have a lot of space and need to fill it quickly, it is better to choose Nikko Blue. However, if you want a more compact hydrangea, then plant Endless Summer Original.

There also is Endless Summer Bloomstruck

In the Endless Summer series, there is another beautiful variety called Bloomstruck. Unlike the Original, it has a more intense color (purple-blue).

This variety looks the same as Nikko Blue without additional acidification of the soil.

Its advantage is that it blooms on new and last year’s growth. Therefore, flowering lasts longer compared to Nikko Blue.

Bloomstruck is more resistant to frost and heat than Endless Summer Original or Nikko Blue.

It also has a compact size. It is 4 feet (1.2 m) high and 5 feet (1.5 m) wide.

All the above advantages make it an excellent alternative to the two varieties that we considered today.

Igor Viznyy

Hi friends, I have been growing plants for many years and love doing it. You can find more information on the page About Author.

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