Choosing The Perfect Hydrangea Cultivar

I was in Japan the first time I noticed hydrangeas. This was not the first time I saw them but the first time I really noticed them. I was driving through the winding road that brings visitors deep into the isolated Iya Valley. Small rustic homes hang onto cliff sides throughout the valley, it was summer and the maple trees still had a month or two before taking on the deep red hues they are known for. At first, I didn’t recognize the plant, not because I hadn’t seen it before but because I had not seen it like this. Seven-foot shrubs with deep green waxy leaves packed with violet flowers bordered the road.

While Hydrangea macrocphylla, or 'Big-Leaf' hydrangea,’ is native to Eastern Asia, you can successfully grow stunning plants in Southern California with ‘Crystal Cove’ and ‘Newport’ being local gems.

Crystal Cove

'Crystal Cove' hydrangeas are named after the seaside state park that is just down the road from Roger’s Gardens. This variety will especially thrive in the coastal communities of Southern California where its pink lacecap flowers will bloom from spring throughout summer. ‘Crystal Cove’ is a compact plant growing 3-4 feet tall and wide. Try pairing its pink flowers and deep green leaves with the blue-green foliage of hostas that can form a ground cover around the plant.

Newport

'Newport' is a sturdy hydrangea variety with mophead flower clusters that, like ‘Crystal Cove,’ will thrive in Southern California gardens. Try a mass planting of them along a back wall then look forward to spring when they will be covered in globular flower clusters. These flowers also work great in cut flower arrangements.

In Southern California, both of these cultivars will appreciate some protection from the afternoon sun and are a good choice for adding color to a woodland garden.

Let’s look more closely at some of the special characteristics of hydrangeas.

Mophead Vs. Lacecap

Mophead and lacecap refer to two different flower structures of hydrangeas. Mophead plants are more commonly known. These flowers are comprised of many sterile florets packed together, creating a dome-like shape. These florets hide the smaller fertile flowers underneath. Lacecap hydrangeas have a round disk of tiny fertile flowers circled by a ring of showier lacy florets.

Change Your Hydrangea's Flower Color With A Little Chemistry

Think back to high school chemistry for this one. pH is a measurement of how acidic or alkaline a substance is. The scale ranges from 1-14 with 1 being the most acidic and 14 being the most alkaline. Acidic objects include lemons and vinegar, and alkaline objects include bleach and drain cleaner.

A fascinating attribute of 'Big-Leaf' hydrangeas is their ability to change flower color based on soil alkalinity or acidity. For blue flowers, grow plants in acidic soils with a pH of 5.5 or lower. Pink flowers require a neutral to alkaline soil of 6.5 or higher. To lower pH, it is easiest to apply an inexpensive product called “Hydrangea Blueing”, which is aluminum sulfate. In Southern California, you won’t need to do much if you like your hydrangeas pink. With our naturally higher pH, this is pretty much the default color. Growing plants in a pot will aid in controlling soil pH.

Will My Hydrangea Rebloom?

Most hydrangeas will put on one fantastic show of flowers in spring and then call it quits for the rest of the year. For these varieties, any amount of watering, fertilizing, and deadheading will not create a second flush of flowers. However, ‘Crystal Cove’ and ‘Newport,’ as well as all of the hydrangea varieties carried at Roger’s Gardens, are reblooming types. These varieties will bloom on new as well as old growth. This translates into a third or even a fourth wave of flowers that will extend the flower season well into summer.

For more information, view All About Hydrangeas and Blooming Hydrangeas.