The Pink Diamond Hardy Hydrangea, otherwise known as the Hydrangea Paniculata ‘Interhydia’ or Mountain Hydrangea ‘Beni Gaku’, Mountain Hydrangea ‘Benigaku’, is a rather well known shrub plant by gardening enthusiasts around the world.
Best known for its low maintenance and moderate growth, this shrub will likely liven up your house (or garden) with its green colored leaves. But, only if you learn how to take proper care of it for it to thrive.
Fortunately, taking care of your Pink Diamond Hardy Hydrangea is not too difficult – as long as you follow our guidelines in this Pink Diamond Hardy Hydrangea Care Guide. Now let’s get started.
The fundamental caring guidelines for every Pink Diamond Hardy Hydrangea can be summed up into the following:
- Water: The Pink Diamond Hardy Hydrangea requires regular watering to maintain moist surface soil without flooding the plant.
- Light: Keep your Hydrangea Paniculata ‘Interhydia’ in an environment where it can receive partial shade to full sun on a daily basis.
- Soil: Make sure to keep the Pink Diamond Hardy Hydrangea in soil with moist but well-draining properties, so ideally, one that is made of sand, loam, and clay.
And as with many other plants, these are the only three care factors you need to remember to make sure your Pink Diamond Hardy Hydrangea is, for the most part, healthy and well to survive.

Scientific / Botanical Aspects
In botanical terms, the Pink Diamond Hardy Hydrangea belongs to the Hydrangeaceae family, the genus Hydrangea and the species Serrata, hence its scientific (or botanical) name Hydrangea Paniculata ‘Interhydia’ (hy-DRAIN-juh pan-ick-yoo-LAY-tuh).
As with other Hydrangea’s, the Pink Diamond Hardy Hydrangea is a deciduous plant, which means it will shed its leaves annually once autumn comes.
Growing Region
The Pink Diamond Hardy Hydrangea is a plant native to the Japan and Korea.
You might be wondering why your Pink Diamond Hardy Hydrangea’s native region is important. Well, if you know where your plant originally came from, you’ll know which environment conditions it prefers, and with it, knowledge on how to replicate it at home.
With this in mind, the Hydrangea Paniculata ‘Interhydia’ will be most used to the heat zones in the 5 – 9 region, as the plant hardiness level falls between 6b, 6a, 7b, 7a, 8a, 8b, 9b, 9a and the ideal climate zone is between 3, 3B, 4, 5, 6, 7, 8, 9, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, H1.
Growth and Size
Growth
In terms of size and growth, the Pink Diamond Hardy Hydrangea is a relatively moderate grower, which makes things somewhat easy for any plant enthusiast.
Size
But, what size of Pink Diamond Hardy Hydrangea are we talking about? What can you expect in terms of height, spread and spacing? Let’s dig in…
The Hydrangea Paniculata ‘Interhydia’ can grow up to 3′ – 4′ (90cm – 120cm) in 3′ – 4′ (90cm – 120cm) and 3′ – 4′ (90cm – 120cm) in 3′ – 4′ (90cm – 120cm).
These dimensions make the Pink Diamond Hardy Hydrangea a relatively large shrub compared to others, so it’s best to keep this fact in mind since it will affect where you want to keep yours at home.
Also, expect it to grow in a wonderful rounded shape, which is something worthwhile to remember when making your garden landscape plans.
This is why experts recommend keeping an area of approximately 48″ (120cm) free so the Pink Diamond Hardy Hydrangea can spread to its best extent.
Water
In terms of watering, the Pink Diamond Hardy Hydrangea is a fairly complicated plant to take care of.
This is mostly because it has a not so straightforward watering schedule and somewhat regular watering needs.
Specifically, most experts agree that the Hydrangea Paniculata ‘Interhydia’ requires regular watering to maintain moist surface soil without flooding the plant.
Which is why it is considered a plant with relatively average needs in terms of water.

Watering
As a rule of thumb, you should remember to keep your Pink Diamond Hardy Hydrangea in soil with moist but well-draining characteristics, as these will guarantee the right conditions for your plant to grow and thrive.
When you consider this, this is why you should aim to choose soil that has good drainage, and moist properties to keep the right moisture levels at all times.
But, if you want a ‘one-size-fits-all’ solution to watering your Pink Diamond Hardy Hydrangea then you should consider the famous ‘finger’ test. To perform this test, you just need to put your finger in your plant’s soil and determine if it’s moist or not. If it is, then don’t water; if it isn’t, then please do. In any case, this test will allow you to know if your Pink Diamond Hardy Hydrangea needs or does not need water, every time.
Soil Mix
As mentioned earlier, the Pink Diamond Hardy Hydrangea prefers to have soil with good drainage, and moist properties at all times, reason why you need to make the soil mix out of sand, loam, and clay.
This is why most experts agree that the Pink Diamond Hardy Hydrangea requires soil with clay, high organic matter, loam (silt), and sand, which will give you the right conditions it needs.
In addition to this, expert gardeners recommend having preferably alkaline, acid or neutral soil.
Light and Exposure
In terms of light & exposure, the Pink Diamond Hardy Hydrangea requires partial shade to full sun in order for it to thrive under the right conditions.
Most experts agree that this shrub will do well as long as you keep it in partial to full sun, and it will be able to grow properly.
Specifically, we recommend that you place your Hydrangea Paniculata ‘Interhydia’ in from little to partial shade (only 2-6 hours of direct sunlight a day), to dappled or moderate shade (under other plant’s canopy), to full and direct sun (more than 6 hours of direct sunlight per day).
Season
Being a deciduous plant, the Pink Diamond Hardy Hydrangea will shed its leaves annually once autumn comes.
But, you can expect it to have its ‘prime-time’ during the summer (early, mid, late).
Flowers
You can expect your Pink Diamond Hardy Hydrangea to flower around the summer months from July to September (summer).
In particular, this shrub is well known for its repeat flowering, flowers for cutting long bloom season, and showy flowers around the plant enthusiast community.
The Pink Diamond Hardy Hydrangea produces some beautiful white, or pink, blue and white flowers around this time of year.
Foliage
The leaves from the Pink Diamond Hardy Hydrangea have a beautiful green color during most of the year.
In particular, they have a simple arrangement with a opposite organization in its leaves.
You can expect the leaves from your Hydrangea Paniculata ‘Interhydia’ to be around (3-6 inches) in size.

Garden
Does your Pink Diamond Hardy Hydrangea have any garden recommendations? Does it serve any gardening purposes? Here’s how you can get the most out of your new plant.
Most Hydrangea Paniculata ‘Interhydia’ owners agree that this shrub will look great in most cottage and rustic gardens of all types.
Other owners consider that they complement well most gardens of informal and cottage, city and courtyard, and in traditional garden styles.
In particular, the Pink Diamond Hardy Hydrangea’s best location within your garden is in patio and containers, beds and borders, and in small gardens, others use it for landscaping in a cutting garden, border, specimen, container, mass planting, or a woodland garden.
Conclusion
Even though we covered a lot of care information for your Pink Diamond Hardy Hydrangea, remember the basics: sunlight, soil and water, as these should be enough to grow a healthy plant at home.