Two Cape growers, Sandwich’s Bob King and Provincetown’s Stormy Mayo, share the straight scoop on growing magnificent Dahlias.
The very name of these regal flowers seems to shout power, prominence, or at the very least, elegance—ah, Dahlias!
These queens of the flower garden have long enthralled gardeners with the huge variety of their colors, sizes, and shapes available online, in catalogs, and at local nurseries.
You can order Dahlia tubers with exotic names like “Impressive Festivo,” or “Obsidian,” that will arrive in the mail looking like small, dried sweet potatoes—or you can cheat, and buy huge pots in full majestic bloom at area nurseries like Hyannis Country Garden, Beacon Gardens at Osterville, Mahoney’s Garden Centers in Osterville and East Falmouth, and Soares Flower Garden Nursery in East Falmouth; but any Cape or Islands flower grower worth their salt has to know and grow Dahlias.
Still, there is a mystique to the success of growing Dahlias in our often erratic coastal climate, where it can suddenly snow in late April and where strong winds can topple the huge “dinner plate” heads of the largest Dahlias. Towering at five to six feet, Dahlias need to be planted deeply, but not too deeply. Most must be carefully staked and tied with the right material, that should be stretchy, but tough enough to take a nor’easter. And then there’s the wintering over process, which can be the subject of hours-long debate among Dahlia growers.
There are gardeners from one end of Cape Cod to the other who swear that the best way to plant Dahlias is in a long trench with the tubers lined up horizontally like lumpy spuds in plain old garden soil, and those who say each finicky tuber clump must have its own carefully dug, deep hole amended with top notch compost, its tubers carefully spread apart and surrounded by the best loam available.
To get the straight scoop on Dahlia growing, we talked to two unrivaled growers, one in Sandwich, Cape Cod’s oldest Colonial town, and the other in the wild and wooly gardening world of Provincetown. Both have been growing Dahlias for decades, and their gorgeous village gardens have become magnets for their neighbors and visiting tourists. Both love to share their know-how and even their Dahlias with friends, neighbors, and local community groups. But there are interesting differences between these Dahlia devotees—and those differences are pretty deeply rooted.
When you talk to Bob King, who is the co-owner of the popular Sandwich eatery Café Chew, it is obvious that this man loves his Dahlias. Since 1984, when he bought the charming antique house he always dreamed of in Sandwich, King has spent endless hours transforming the yard, surrounding his abode with flowers, mostly Dahlias.
Fortunate to have a double lot in the closely inhabited village, King’s flowerbeds spill out around his Early American glassmaker’s cottage like petticoats on an unadorned Colonial maid. King says he has well over 100 Dahlias planted in his gardens—and every year that number grows as he is enticed by catalogs and area nurseries, buying must-haves with names like his most recent purchases, “Chinatown,” “Tartan,” and “Night Butterfly.”
“My latest passions just arrived in the mail,” says King in early April, when he is about to descend into his house’s old root cellar to unearth three large bins of sleeping Dahlia beauties, each carefully wrapped in a brown paper bag and labeled with a name, a description of the particular Dahlia, and its size. ‘I know I don’t need any more Dahlias,” he admits, “but my new love are the Collerettes and then I love the new Beach Balls . . .”
King says he may be “obsessed” with Dahlias (a word that our Provincetown grower also uses repeatedly) but says he is a self-taught, seat-of-the-pants grower, who learned how to succeed in the 1980s and ‘90s by talking to a local long-time gardener at Sandwich’s former Agway store, now a popular plant and garden center called Scenic Roots.
“Ray Kutil–whose daughter, Donna, and her brothers now run Scenic Roots–gave me lots of good advise about growing Dahlias,” shares King. “He told me not to be afraid of throwing several tubers all together in each hole, which means my Dahlias sometimes grow like shrubs because the holes are so full of bulbs. I learned by trial and error over the years.”
King, who amends his Dahlia beds with healthy compost, shares that one of his least favorite things about growing Dahlias is the need for staking, especially for varieties like his current favorite “Beach Ball,” which have enormous 8-10 inch heads.
“One of the things I don’t like about growing the Dahlias is the staking,” says King. “So I do it early, first thing, to get it out of the way. I learned the hard way that stakes should be dug down deep, at least two feet. I use a strong rubber mallet to pound five-foot stakes into the ground. Then I back fill the hole to a depth of 5-6 inches for each planting—the hole should be twice as wide as each clump of tubers.” After each clump is planted, King numbers the stake and creates a map that identifies each numbered Dahlia, so he can identify his varieties before winter storage time.
King says he differs from many Cape Dahlia growers by planting his bulbs early—right after April 15th, a surprisingly early date for these frost-tender beauties that originally flourished only in their native Mexican soil.
“I believe it is okay to plant that early because the Dahlias are safely far enough down, 5 or 6 inches,” explains King. “For me, this has always worked. And it means that by May 15th, we are off to the races with the Dahlias all planted, and we have time to work on our other gardens.”
King says he does not believe in the need for intensive fertilization, or even constant irrigation. “To be honest, I don’t find the need to water my Dahlia beds a lot,” he asserts. “Once a week, I just put the hose right down on the ground and let the water run for 20 minutes.”
Once the Dahlias begin to shoot up to two-feet by around mid-June, King ties the stalks to each stake with a stretchy elastic cord called Kloud City that he found online. “It works perfectly, “ he says. “One of the hardest things about growing Dahlias on Cape Cod is the wind—and with this stretchy cord, the plants won’t topple over!”
King notes that his Dahlias don’t seem to attract a lot of pests, despite a healthy population of “little hoodlum” chipmunks, voles, and rabbits. “Here’s another one of my secrets,” he discloses. “I have two cats. They keep the beasts away.” Insect invaders such as earwigs are sprayed a couple of times a season with insecticidal soap. And then of course, to keep the Dahlias looking superb, there is weekly deadheading.
King declares one of his current favorite Dahlias is the Cactus variety, described as having rolled petals creating a prickly, or cactus-like flower. The Dahlias of all shapes and sizes begin to strut their stuff in July, but King notes their crowning glory comes in September. “The Dahlias really love it when the Cape’s weather begins to cool down. Of course, they do like sun, but not serious heat,” he says. “The first week of September, they are at their beautiful peak.”
After Halloween, it is time for this dedicated Dahlia man to put his beauties to sleep, a process he has perfected over the last four decades. “I think wintering over is one of the most difficult things about growing Dahlias,” shares King. “If it is too warm, the tubers will shrivel up—too cold and they will freeze and be mush. Luckily, I live in an old antique house with a root cellar where it gets cold, but never freezes—and where it never gets too warm.”
King says he does not dry the Dahlias out completely before storing them away. “I just bang the dirt off. Each Dahlia gets their own bag, which is folded in half and put in a big crate. I have three crates, which I check once or twice a winter. If the bulbs feel a little dry in February, I sprinkle them with a little water,” he explains.
Provincetown’s Dr. Charles “Stormy” Mayo says that growing Dahlias is “just another of three main obsessions in my life,” one of which has made this 12th-generation Cape Codder famous far beyond Provincetown. Mayo is a founder, the Senior Scientist and Director of the Right Whale Ecology Program at Provincetown’s Center for Coastal Studies, an internationally acclaimed marine research, education and rescue organization.
Mayo, who has a PHD in Marine Biology, is widely respected for his work with the seriously endangered Right Whale population, who frequent the waters off Provincetown every spring to feed on zooplankton. He admits that while helping to save these magnificent creatures (it is estimated that there are only 336 Right Whales still in existence) is his life’s work, the propagation of new Dahlias is fast becoming his dearest, and most interesting “obsession.”
It is a bit of a challenge to reach Mayo on the phone in between his Zoom calls with NOAA’s (National Oceanic and Atmospheric Administration) Woods Hole office, a planned whale watch viewing with a curious Massachusetts Senator, and the careful propagation of a Dahlia variety never before seen on the planet. Mayo is an engaging mixture of a brilliant scientist, a salty, blue-blooded Cape Codder, and what he calls a “wacky guy” who spends countless hours pursuing the propagation of his beloved Dahlias from all three methods of starting new varieties; propagation from seeds, cuttings, and tubers.
This is a Dahlia grower who can tell you in detail about the fascinating genetics of Dahlias (one of the most diverse plants on earth, Dahlias are Octoploids, which means they have 8 sets of chromosomes, while the rest of the monotonous world only has two) and who has been known to drive all over the Cape and beyond in search of new and ever more intricate, beautiful, huge, colorful, tiny, ever-diverse Dahlias to grow.
Mayo shares he has 11 gardens on the two Provincetown properties he owns, one the home he shares with his wife, fellow scientist, and Dahlia lover, Laura Ludwig, and the other a waterfront lot with a guesthouse he inherited on Commercial Street. Mayo’s main Dahlia gardens flourish with wild abandon around his antique Cape home on Bradford Street.
Mayo estimates that this year’s gardens will be planted with more than 700 plants, a profusion that delights the Provincetown community and tourists so much that his property has become a must-see local spot. “Some years, we have so many tubers, and plants that we have a giveaway day at our Bradford Street home,” explains Mayo. When he puts out bouquets on the street, delighted viewers often leave behind donations, which are immediately squirreled away for future Dahlia-growing operations.
Mayo’s desire for ever better, more splendid, and especially unusual blossoms has inspired him to charge down a new path in the last few years—he has chosen to create new Dahlias from all three propagation methods. “I have just over 400 seedlings that I grew this winter in my tiny greenhouse,” he says. “In my cellar, I have about another 800 Dahlia cuttings that are being incubated to produce plants. And that doesn’t include all the tubers that I have wintered over in my cellar, which number around 1,000 from about 300 cultivars.”
Mayo admits he will drive far and wide to beg, or borrow cuttings from coveted Dahlias in friends’ or acquaintances’ gardens. “If I make the cuttings in late September, they are usually rooted by mid-December, which is done with liquid rooting hormone in Vermiculite,” he explains. “Then I transfer the cuttings into Solo cups with soil and put them in the greenhouse. They fit perfectly in 130 boxes I built specially, and by April they are ready to be hardened off.”
Mayo says he recruits several family members and friends to help plant the Dahlia beds in mid-May. “We rototill the beds and then put in a lot of horse manure from a friend’s stable, and I use a specialized, long term, glass-faced ground cover called TYPAR to keep weeds down, followed by a covering of salt marsh hay,” Mayo illustrates. TYPAR allows rainwater and sunlight to penetrate while stopping the weeds. “I use TYPAR on everything in my gardens so I don’t have to weed,” he says, “And it lasts for a couple of decades.”
Individual holes for each Dahlia plant are punched into the TYPAR fabric, stakes are put in, and then Mother Nature takes over. Mayo says he does not bother with extra fertilizer and waters only when necessary. Like his fellow Dahlia grower, Bob King, Mayo claims he is “not a fancy gardener.”
Mayo notes that his gardens this year will be “up to 70 percent” cuttings from established plants, with the other Dahlias coming from wintered-over tubers—or from his other current obsession—Dahlias started from seed. “It turns out that the Dahlias we all have were originally from somebody taking the seeds of a Dahlia and growing them,” explains Mayo, who has visited the forests in the cool highlands of Central America, where the original Dahlias were discovered “probably by the conquistadors.”
Unlike cuttings and tubers, which will also grow into exact replicas of the “mother” plant, the seeds of Dahlias can be teased from the seedpods in the fall. These seeds, the result of pollination by bees, or artificially pollinated by Mayo, create completely new, unique varieties. And that is Stormy Mayo’s current greatest obsession.
“The truly fun thing for me is that one morning, say in late August, or early September, I go out to look at the Dahlias planted from seed and the first flowers are there,” says Mayo, a touch of wonder in his voice. “You know, this flower is a completely new thing, it’s never been grown on earth before. It’s always such a surprise. I have a full, completely new flower, and it just blows my mind!”
And then, Mayo has to go—he needs to answer more texts about the Right Whales, to turn his attention from treasured seeds no larger than a fingernail, to caring for one of the planet’s most endangered, largest creatures. And you can bet that the “obsessing” of this “wacky guy,” and his fellow, no less “obsessive” Dahlia grower, Bob King of Sandwich, will help all Mother Nature’s creations endure, making the planet a healthier, more beautiful place for all of us.
For more information on the growing, propagating, and sharing of Dahlias, go to the American Dahlia Society’s website, dahlia.org.
Susan Dewey is a former editor at Cape Cod Life Publications as well as a grower and lover of Dahlias and organic vegetables in a year round hoop house at her Centerville home.