From “Plants of American Gardens” by Peggy Cornett Newcomb in Keeping Eden: A History of Gardening in America, edited by Walter T. Punch:
“Although introduced as late as 1796, zinnias (Zinnia elegans) seem always to have carried the reputation of ‘old maid of the garden.’ During the first half of the nineteenth century, this coarse flower with plain scarlet and crimson blossoms persisted reluctantly in the trade….
“With the advent of double types in the late 1850s, enthusiasm for its possibilities increased. Charles Hovey observed in 1864 that, although still improving ‘under the hands of skilled cultivators… there is no reason to suppose it will not in time give us as great a variety as the dahlia.’
“Dwarf, double forms did arise to enter the ranks of bedding-out plants, but their ungainly or unattractive habit and unreliable colors from seed rendered their value questionable in highly controlled situations. Giant or mammoth strains entered the trade by the late 1880s, allowing the zinnia’s ungainly character full expression….
“This branching, freely growing flower delighted the creators of the ‘old-fashioned border’ during the early twentieth century. But as late as 1929 we are reminded of the zinnia’s earlier reputation. As [Harold] Hume observed, ‘Today it has grown forth into the prize and pride of many a garden… gorgeous and self-assured, new formed, new faced, new named, its despised position of former years entirely forgotten.'”
From “Au Revoir” in Open the Door: A Gathering of Poems and Prose Pieces by Elizabeth Yates:
I thought I could not bear to see
the zinnias go —
color of fire they were against the
garden’s green:
brick red and crimson, scarlet, gold
and flame,
fawn and maroon, cerise and coralline.
Frost came one night,
finis in its track:
flowers turned to cinders,
foliage went black.
There were no zinnias left to crown
the gardens year,
but on the lofty maple towering overhead
leaves were burning skyward, wind-driven flames,
copper and saffron, cinnabar and red.
Hello!
This is the third of three posts with photographs of Zinnias from Oakland Cemetery that I took in August and in October. The previous two posts are Dazzling Autumn Zinnias (1 of 3) and Dazzling Autumn Zinnias (2 of 3).
I think my photos cover most of the colors in the Elizabeth Yates poem above — especially since some of those colors are shades of the others — so we can pretend I matched the photos to the poem. I gathered all the double-flowering Zinnias together for this post, not realizing their significance until I started assembling them and conducting some research on this particular Zinnia form.
I first photographed Oakland’s Zinnias in 2021, and at the time didn’t know what they were (and hadn’t yet discovered PlantNet for plant identification), so simply called them wildflowers (see Ten Wildflowers and Three Butterflies) — because they resembled those motley collections of flowers that you might find at the edges of a forest or see on the side of a road. I didn’t photograph them again until 2023 and 2024, when they had incrementally spread across their hill and homeland, increasing their overall presence in the landscape each subsequent year.
While learning more about Zinnias for this post, I looked through all the previous years’ photos and saw that I didn’t have any showing the double form. This introduced a potential mystery: either I just hadn’t photographed any double Zinnias in 2023 or 2024; or, there weren’t any. Given that each of my earlier photoshoots followed the same pattern as this year’s trip — two visits in late summer and early fall — it seemed unlikely that I would have passed over them, especially given how much time I spend dwelling over any batch of flowers to capture their colors and shapes. So it’s more likely that they weren’t there, and that either Oakland’s gardeners planted them in 2025, or some of the single Zinnias developed the double form this year. To speculate on and potentially resolve this part of the mystery, let’s turn to the landscape itself and observe the messages it might be sending us.
Here we have two photos of double Zinnias from the galleries below. In the first photo, we see a double Zinnia growing in front of some Iris leaves, between — shall we say — a rock and a hard place, in a crevice barely six inches wide. In the second photo, we see one double Zinnia growing among a half-dozen single Zinnias. Neither of these placements suggests intentional planting: capable gardeners are unlikely to try growing one Zinnia in a crevice, nor plant one double among a group of singles. Instead, both growth patterns reflect the randomness typical of plants that are propagating on their own, where fertilized seeds have been distributed by pollinators or the wind, and favorable conditions let them sprout, take root, grow, and bloom from one season to the next.
For this speculation to be true, it would have to be possible for double Zinnias to evolve from single Zinnias. To help me understand whether or not that was possible, I turned to my digital research assistant, Claude.AI, and asked some questions about how a generational transformation between single and double Zinnias might take place. Here’s part of the explanation, where “ray florets” refers to each row of flower petals a Zinnia typically produces, and “disk florets” refers to the tiny composite flowers that grow at the top of a Zinnia’s pear-shaped seed structure.
This transformation doesn’t happen randomly — it’s the result of mutations in specific developmental control genes that regulate how the flower forms as it develops. To understand this, you need to know a bit about how composite flowers like zinnias are built at the genetic level.
During flower development, the plant must make a series of decisions about what kind of structures to produce and in what order. In a normal single-flowered zinnia, the genetic program says something like: “First, produce one whorl of ray florets around the perimeter. Then, switch modes and fill the center with disk florets.” This creates that classic daisy appearance — showy outer ring, functional inner disk.
The mutations that create double-flowered forms disrupt this tidy program in one of several possible ways. Some mutations affect genes that control the transition from “make ray florets” to “make disk florets.” When these genes malfunction, the plant essentially forgets to make the switch, or makes it much later than it should. The result is that the flower keeps producing row after row of ray florets instead of transitioning to disk florets. This is why heavily doubled zinnias have so many petal layers — the developmental program that should have said “stop making rays, start making disks” failed to activate properly or activated much later.
The production of “row after row” of flower petals is exactly what we see in fully-formed double Zinnias like those in my galleries below. Claude also went on to describe the genetics by which this transformation might occur in some detail — a couple of thousand words of detail, actually — and explained that, due to cross-breeding by humans or nature, any given Zinnia might contain the potential to produce flowers in the double form, and this potential might partially express itself between generations.
This seems to be confirmed by my Zinnia photographs from previous years: here we have some examples of that doubling potential emerging over time, where two of my photos from 2023 and two from 2024 show the flowers starting to develop a second row of ray florets. These aren’t just overlapping petals from a single row, but petals that are clearly growing from a slightly higher point at the center of the flower, and on top of the first row. That horizontal or height difference is most evident in the first photo; though once you see it, it’s easy to identify in the other three photos as well.
You never step in the same garden twice, of course, and I don’t know which of these Zinnias are perennials and which ones are prolifically-seeding annuals — so it’s not possible to know if I’m observing the same plants taking on different forms, or new variants expressing their double potential. In either case, however, next year’s crop will likely include even more double-flowering Zinnias, and, if it does, that will be strong evidence that the plants are producing additional forms on their own as each generation reappears.
Thanks for reading and taking a look!
Such colourful blooms and delightful photos