“A delightful summer-flowering shrub, H. serrata ‘Bluebird’ is the perfect choice for any garden that does not have the space for one of the larger lacecap hydrangea varieties. ‘Bluebird’ is a slender shrub, with upright tan-colored stems and painted dark-green leaves flushed purple red. In midsummer the delicate lacecap flower heads appear; these are purple-pink on alkaline soils, but bright gentian-blue on acidic soils. Each flower head consists of a flattened cluster of tiny fertile florets surrounded by larger, showier, sterile or ray florets. ‘Bluebird, along with other H. serrata varieties, has smaller, more refined flower heads than familiar lacecap hydrangeas. As the season progresses, the color of the flowers changes to purple-green, and the wine-red color of the foliage becomes more intense toward fall.
“‘Bluebird’ is a lovely hydrangea to grow in sun or in light shade with perennials and roses. Its compact habit makes it suitable for narrow borders…. H. serrata ‘Tiara’ is similar in habit to ‘Bluebird, but it has more sterile florets in each flower head. The flower color is more mauve, and the fall foliage more intensely crimson in the sun. H. serrata ‘Rosalba’ has fewer, large sterile florets, which are initially white but soon change to crimson. Its fall foliage is rich purple-red. H. serrata ‘Miranda’ has very dome-shaped flower heads, which turn a vibrant shade of blue in acidic conditions.”
I took most of these photos a little later in the season than those in the previous post, and — as is described in the quotation at the top — you can see how many of the tiny flowers have shifted color from mostly-blue toward a mix of purple, pink, and light green. I had actually thought the color-shift was from soil variations (as hydrangeas are known for their fascinating color changes), but this may be a late-summer seasonal change, since mine are all planted together.
If you’d like to see the color variations presented by some of the Bluebird’s close relatives (those mentioned in 1001 Plants to Dream of Growing above), click these links:
Rosalba looks especially scrumptious: that mix of red and pink among the flowers and the florets (which are white or very light blue in the Bluebird hydrangea) may just earn them a place in my garden next year.
“A near neighbour and relative of H. macrophylla, H. serrata hails from the wooded mountains of Japan and Korea, where it is sometimes called ‘tree of heaven’. In the uplands, well away from the sea, temperatures often dip below freezing so, for garden purposes, it is noticeably hardier than its cousin….
“While the vulnerability of H. macrophylla comes from the length of its growing season, starting too early and going on too late, H. serrata has a much shorter growth period so it is hardier in the face of cold — although it is no fan of blazing sun.
“Like H. macrophylla, H. serrata likes partial or dappled shade so it can be used in a similar way in the garden. It is less tolerant of exposed, windy or very warm locations and it doesn’t thrive in wet soils, which makes it less suited to coastal and boggy sites. On the other hand, the plants tend to be smaller, at around 100cm (40in) tall, so are suitable for compact modern gardens.
“The species has lacecap flowers and serrated leaves — hence the name — and does well under trees. A number of cultivars, specifically Grayswood, Preziosa and Glyn Church will go through several colour changes throughout the season — but since they are not susceptible to pH, these are consistent in their inconsistency. The white cultivars will remain white regardless of soil pH, but the other pink and blue cultivars are moderately susceptible, so situations arise where, for example, Bluebird, grown on alkaline soil, will produce flowers that are noticeably pink.”
the deepening blush of hydrangea flowers late August chill
Hello!
Here we have the first of two posts featuring Hydrangea serrata ‘Bluebird’ — most commonly referred to as the Bluebird Hydrangea — from my garden. I have about six of these plants at a boundary between shade and sun in my back yard, where most of the time, they seem pretty happy. They bloomed well for several years running, then they got frozen and failed to bloom for one season, then this year returned once again. I always like to see them in early summer, and they look especially nice in late afternoon and early evening, when their white florets glow and the cluster of blue and pink flowers look more saturated as the sun goes down.
The part of this lacecap-style hydrangea that usually catches the eye includes both the cluster of tiny flowers at the center and the white florets that seem to float around them. Technically, only the lacecap portion contains flowers; the white florets are produced (the hydrangea tells me) to demand the attention of pollinators by providing some white-on-dark contrast.
These baby Bluebirds can be hard to photograph, and when I look at their photos from previous years, I see that I’ve often struggled to get the colors and focus right. Focusing at close range is difficult because the cluster of flowers may extend five inches or more from front to back, and the flowers in the cluster are extra-tiny, entangled with each other, and hard to differentiate in the camera’s viewfinder. And they move easily in the wind, making my eyes wobble.
Examine, if you like, the first two photographs, and you’ll see what I mean: the foreground white floret is in focus as are some of the blue flowers, but as the distance from the camera increases, the cluster of flowers becomes blurrier as do the two background florets. If I use a narrower aperture, I can get more of the flower cluster in focus — but then too much of the background also ends out in focus and it becomes difficult to separate the flowers from the background.
As you move through the galleries below, you can see how I handled that: by either moving in closer and eliminating many of the wee flowers from the image; or by moving back and taking a wider shot, where the fact that some of the flowers are out of focus becomes less apparent. I have sometimes tried adding LED light or using a flash, but then they look like they’re studio portraits rather than nature photos. So while I wasn’t entirely satisfied with these images, I decided to post them despite being unable to achieve perfection — whatever that is!
The hydrangea pink cheeked nods its head a paper brain without a skull
a brain intestined to the invisible root where beside the rose and acorn
thought lies communal with the brooding worm True but the air remains the wanton the dancing that holding enfolds it
a flower aloof Flagrant as a flag it shakes that seamy head
or snaps it drily from the anchored stem and sets it rolling
Hello!
I’ve often photographed hydrangeas during the winter (see, for example, Winter Shapes: Hydrangea Skeletons (1 of 2)) because I like their graceful lines and the way their desiccated flowers catch light. This year, however, I came across some leaves of an Oakleaf Hydrangea at just the right time, shortly after we’d had a few freezing nights to jack up their colors. The first two photos below and those toward the end (including the ones I recreated on black backgrounds) showcase what I saw. The sunlight was filtered by clouds but quite bright, so each of the leaf photos came out with a lot of detail and color, along with a nice glow against their monotone backdrops.
You might be wondering, as I was, how it happens that hydrangea leaves reveal so many different colors in autumn and winter — considerably more colors than you would typically find in individual leaves of most trees or shrubs. With no background in chemistry, I puzzled a little (as in: a lot) over how to explain it. I wanted to point at something and say “this is where all those colors came from” — but of course it’s more complex than that.
Helping me unravel complicated concepts is one of the few consistent uses I’ve found for the new AI chatbots — because you can ask questions then continue asking follow-up questions until you feel like you’ve actually learned something. Pretty much any starting question works to get the conversation going, so to my imaginary friendClaudeAI, I asked what I wanted to know:
When hydrangea leaves change color in the fall or early winter, they exhibit a wide range of colors, even on the same leaf. Is there something different about hydrangea leaves that make them appear more colorful in the colder seasons than the leaves of other plants?
The key part of the question — “is there something different about hydrangea leaves…” — gets the bot to answer with a “compare and contrast” response, an approach that can help lead to other questions and answers. So to this first question, ClaudeAI responded, uh, thusly:
Hydrangeas do tend to display a wider range of fall leaf colors compared to many other plants, and there are a few reasons for this:
Soil pH – Hydrangeas are unique in that the soil pH affects their flower color. This is because soil pH impacts how hydrangeas take up and process aluminum from the soil. Aluminum causes hydrangea leaves and flowers to turn shades of blue and purple. In more acidic soils, they take up more aluminum and become bluer.
Pigments – Hydrangeas naturally contain anthocyanin pigments in their leaves which give them red, purple, and blue hues. As autumn arrives and chlorophyll breaks down, these other pigment colors become visible. The specific anthocyanins and their concentration impact the resulting fall leaf shades.
Weather shifts – Cooler fall temperatures, shorter days, and weather events like rain or frost trigger chemical changes in hydrangea leaves. This leads to both the loss of green chlorophyll and the production of more vivid pigments. The timing and conditions of the season expose the wide color range hydrangeas can display.
So while many leaves turn yellow or brown in fall due to carotenoids, hydrangeas reveal both those warm shades and vivid crimsons, purples and blues that were present yet masked by chlorophyll through summer. Their fall foliage rainbow results from both unique pigments and responses to the weather.
There are two characteristics of this response that I found helpful. First, it confirmed that, indeed, there is something unique about how hydrangea leaves change color in the cooler seasons (so it wasn’t just me making stuff up, like I like to do). Second, the response focused on the leaves — not the hydrangea flowers — and it was the leaves I wanted to learn more about. By contrast, when I tried posing the same question as a Google search, I got back over 49,000 results — which were more focused on the well-known fact about hydrangeas that you can change the flower colors by changing the soil pH. It would have taken me hours to splog through those results to get a straight answer about the leaves rather than the flowers — which I was happy not to do.
My conversation with the bot went on for several days (!!) because I kept thinking of more clarifying questions. But the concise overview of this phenomenon (written by me (the human), not the bot) goes something like this:
Just like hydrangea flower colors can be altered by changing their soil chemistry, their leaves contain the potential for alternate colors too. At the cellular or molecular level, hydrangea leaves contain more colors than you see during the plant’s blooming season — including red, blue, yellow, and orange — but you don’t see them until the plant’s production of chlorophyl begins to cease and the dominant green colors subside. What colors ultimately appear is essentially a chemical reaction and depends on several factors, including moisture, temperature swings, and the chemical composition of the soil. You might sometimes see these colors if you look very closely at a hydrangea leaf (particularly late in the blooming season, just before their colors change) — especially blue and red or purple, and the (potential) leaf colors are often in the same color ranges as the plant’s flowers. Voila!
For what it’s worth, I used ClaudeAI to check my understanding, copying the paragraph you just read and asking it if I had summarized our conversations correctly. Here’s the response I got back:
That is an accurate summary covering the key points we discussed about hydrangea leaves and their fall color change. You concisely captured information about:
How soil chemistry affects hydrangea colors, both flowers and leaves
The presence of multiple pigments (red, purple, orange, yellow) at the cellular level even when dominated by green chlorophyll
Chlorophyll fading allowing underlying colors to emerge in the fall
Factors like weather, light, and soil impacting final fall leaf tones
Anthocyanins providing blue/purple and carotenoids providing orange/yellow tones
The potential to see hints of colors before full change occurs
Similarity between potential leaf pigments and flower colors
I think you distilled the mechanisms behind the visually stunning hydrangea foliage transformation very well into key takeaways. Connecting the science to the observeable phenomena will help readers appreciate how much is occurring on a microscopic scale to create such a vibrant macro display in fall. Nice work summarizing the essence of our discussion! The paragraph flows and communicates the core concepts accurately and clearly for a general audience.
Fascinating, no? It cracks me up that the bot’s response includes compliments — part of its insidious plot to convince me it’s human, I’m sure — but, hey, I’ll take them!
