Working out of an old goat barn on the farm, Pettengill displays a large cache of "natural elements" she uses to design for weddings, parties, and other celebrations, as well as corporate holiday installations. In warmer weather, she also does rooftop, deck, and courtyard gardens, mostly in Center City.
Favorites are easy to divine. A basket of yarrow dries by the door. Nearby are trays of quirky sedums and stems of millet and wheat, along with berry-laden boughs of nandina and bittersweet, and tendrils snipped from a wily passionflower vine.
But hydrangea, with its sweet open face, is her all-time favorite. She cannot resist 'Tardiva,' 'Limelight,' or 'Endless Summer,' all fabulous in bloom and exquisite when dried.
And evergreens, especially dwarf varieties that are more yellow or blue than green, as in Chamaecyparis pisifera 'Gold Dust,' a cypress, and Cedrus deodara 'Divinely Blue,' a cedar of Lebanon.
Pettengill likes distinctive leaves, too - wild grape, cabbage, magnolia, Virginia creeper, and fig; rose hips from the invasive floribunda in her own fields; and even the humble pinecone, which, unfortunately, has been devalued from overuse.
Pettengill's pinecones look dipped in sugar. Sweet.
There's so much beauty in this plain old barn, we almost forget today's assignment: to consider holiday arrangements that are simply grand and grandly simple, a task many a harried host relegates to the bottom of the to-do list.
Which is a shame, because to watch Pettengill put her tabletops together is to be reminded that arranging flowers - and seedheads, cones, berries, and branches - is great fun. And that, like the holiday meal, it should be enjoyed, at least for a day.
Time out to describe this day. It is so autumn - warm, golden, with a big sky, a feathery breeze, and a little background noise.
Just over the fence, half of Pettengill's Mother's Day present - two pigs - are doing some foraging of their own. Four chickens are the other half. They're a fitting gift for someone who grew up in Richmond, Va., and Greenwich, Conn., climbing trees, picking flowers, and charging around the outdoors.
Unlike career-changers who come late to horticulture, Pettengill, now 58, took a direct route; she's a horticulture graduate of Temple University/Ambler. Even then, she recalls, she felt the need to "deprogram" some of the traditional design concepts being taught.
"What they made me do was stiff. I felt like a failure. I couldn't do it," she says, "so I just started doing it naturally."
And "it" should be done in "special vessels that are dressed up and played with," insists Pettengill, proprietor of Urban Botanical. Ultimately, they provide structure and framing to a design.
No surprise: Pettengill forages for "vessels," too, at yard sales, antiques stores, flea markets, and elsewhere.
She finds artists' bowls, vases, and cups. Turquoise Ball jars, glass globes, light-covers, and goblets. Old metal food presses, found objects, and family heirlooms steeped in sentiment.
Friends show up with finds. Growers and nursery owners let Pettengill "pick and hunt." She collects funnels, beakers, and test tubes. The sterling silver salt holders and dishes belonged to "awesome Aunt Mabel," the engraved silver vase, bread baskets, and candlesticks are from Pettengill's paternal grandmother.
"It's a shame that people have so many things locked away. They don't want to bring out the silver polish," she says, offering this advice instead:
"Live with your antiquities! Get the silver polish out and use them."
Today, Pettengill has inverted a rosebud inside a china cup, with variegated ivy leaves pressed between cup and saucer, an arrangement that emphasizes "the delight of the back of a rose," she says.
In a glass goblet with hollow stem, she has put a giant magenta dahlia, ivy, and solidago, or goldenrod. "It's so dimensional," Pettengill says with obvious pleasure.
She has filled a crystal sherry goblet, her grandmother's, with wavy red celosia, then popped a fulsome artichoke on top. Wheat stems add an earthy accent.
And a long-stemmed, wide-brimmed vase fairly bubbles with more velvety celosia, pumpkin-colored bittersweet, bluish hydrangea, and pale green orchids.
"You have to have materials on hand and be flexible," says Pettengill, who strives to keep those materials to a minimum. The goal is an ikebana-like simplicity that is not necessarily symmetrical.
This does not mean flat or without color. Pettengill enjoys "gloss, fuzz, and pricklies," and hues both bright and subtle. Sedums, "the greatest little plant ever," can be all of the above: knife-sharp or fat with water, blue-green, pale green, coral, or aubergine.
And imagine nearly-green yellow blooms next to ones that are mango-bright. Or a tabletop showered with bold orange petals from marigolds or Mexican sunflower.
One material Pettengill never seems without is a lace tablecloth. It helps "dress the table," preferably for the season, which at this time of year means "celebrating the harvest and soon, the beginning of winter."
The harvest comes first, with thanks.
Read gardening writer Virginia A. Smith's blog at www.philly.com/ginny
VIDEO: The inspiration behind one of Helen Pettengill's holiday floral designs.
Contact garden writer Virginia A. Smith at 215-854-5720 or firstname.lastname@example.org.