The Gifted Gardener Offers Advice For Continuous Bloom

By Shannon Hicks

Pam Duthie offered two lectures during The 2005 Connecticut Flower & Garden Show, sharing advice from her Continuous Bloom books. During her first lecture on February 25, “Designing for Continuous Bloom,” Ms Duthie told her audience that it needs to know two things if it wants to achieve continuous bloom.

“You need to know when your plants bloom and for how long they will bloom,” said Ms Duthie to a meeting room that was filled to standing capacity.

Ms Duthie was one of the Flower & Garden Show’s key speakers. Among her credentials: she is the owner and president of The Gifted Gardener, a landscape design and consulting film in the Chicago area that specialized in perennial gardens. She is also the author of Continuous Bloom (Ball Publishing, March 2000), a month-by-month guide to nonstop color in the perennial garden; and Continuous Color: A Month-by-Month Guide to Shrubs and Small Trees for the Continuous Bloom Garden (Ball Publishing, April 2004).

“Continuous bloom is every gardener’s dream and I believe it is achievable with a little planning,” Ms Duthie said.

Continuous bloom does not mean color in a yard year-round. According to Ms Duthie, who has written a pair of books on the subject, it means enjoying color and foliage from the time the first colors begin — usually as early as March — until the latest colors fade in late autumn. A slide lecture and a pair of handouts helped her audience follow her suggestions.

Colored foliage is an important part of what Ms Duthie called The Continuous Bloom Garden. While most of us don’t have the time available to devote our lives to full-time gardening, there are usually a few plants we can begin with and expand from there. Using perennials make life easier — once you’ve mastered their growing seasons, they can be counted on for a number of years.

In designing a continuous bloom garden, Ms Duthie suggests three points: First, know in which months the perennials bloom; second, choose plants that bloom for at least eight weeks for a core group of perennials; and third, fill in the garden area with other plants that will support the long-bloomers.

Perhaps the easiest area to garden is that which receives full sun at some point during the day. The plants Ms Duthie introduced first will do well in these conditions.

A sunny garden will begin blooming as early as May with Blue Wonder Catmint (Neteta mussinii, “Blue Wonder”), or May Night Salvia (Salvia x superba, “May Night”). These plants can remain in bloom until as late as October.

“This plant will keep blooming unless you cut it back, which you definitely want to do because it will otherwise seed your entire garden,” cautioned Ms Duthie. Because it is aromatic, the plant will also keep deer and rabbits away.

A similar pest-repelling effect will be found with Moonshine Yarrow (Achillea x, “Moonshine”). This is an aromatic plant with a “nice flat yellow bloom bed with silver foliage,” she said.

For June, a month when many are thinking roses, Ms Duthie’s favorite is Carefree Delight Rose (Rosa “Carefree Delight”), a plant that needs only low maintenance and is not too susceptible to plant diseases. Another favorite, Knock Out (Rosa “Knock Out”), gets to be between 30 and 36 inches tall — so plan accordingly, she cautioned.

“This plant is lightly fragrant, you never have to spray for mildew, and they just stay beautiful all summer long,” said Ms Duthie. “Best of all the colors is crimson, and it will go with all those pastel shades that will begin to show up.”

Knock Out is also good for partial shade, and it will bloom “prolifically,” said Ms Duthie, even if it isn’t regularly deadheaded.

Another favorite rose — and one that was only recently introduced (2001, by Radler) — is Carefree Sunshine Rose (Rosa “Carefree Sunshine”). This is also a late spring-early summer bloomer, with a medium yellow flower.

Another long bloomer, Rosy Returns Daylily (Hemerocallis, “Rosy Returns”) is prolific all summer and offers a good color for blending. Rosy Returns comes up coral salmon, “not pink,” said Ms Duthie.

The daylily Happy Returns, an offspring of the popular “Stella d’Oro,” offers three-inch, soft lemon-yellow flowers from May until the first hard frost of the year. Its compact habit makes it ideal as a front border plant, it thrives with minimum care in full sun to partial shade, is very heat tolerant, and it attracts butterflies.

Geraniums are a big plant for the hottest days of summer. Ms Duthie’s favorites are Lancaster’s Geranium (Geranium sanguineum var. striatum) — her absolute favorite, with “a roundy-moundy non-floppy habbit” that will sometimes pop later in September, and also tends to give red color into autumn — and Rozanne Geranium (Geranium, “Rozanne”), which she called “delightful.”

For late summer blooms, try The Monk Aster (or Frikart’s Aster; Aster x frikartii, “Monch”). This plant, the longest blooming of the asters, will start in July and often goes straight through October before giving up for the season. The plant is easy to grow, so good for beginners; is lovely fresh and dried, and has a pleasant fragrance.

This aster is usually seen as a potted dome about a foot tall and equally wide. In the ground Monk Aster will grow to two or three tall and wide.

Healthy plants become covered with dozens of lavender-blue daisylike flowers, each about 2½ inches in diameter and highlighted with a yellow center. These flowers will cover the entire plant, practically obscuring its leaves, and last for at least eight weeks.

It has a loose brushy form and its colors make it perfect to combine with golds and oranges of other species, or left alone is a perfect complement to autumn’s colors.

Another late bloomer, Gateway Joe-Pye Weed (Eupatorium maculatum, “Gateway”) grows to six or seven feet tall and has “a huge cloud of rosy colored flowers,” said Ms Duthie. This is another plant that will attract butterflies during the summer. An added bonus: It will also feed the birds all winter.

A shady garden may not be as easy to cultivate as full sun, but those who persevere can also have something special to enjoy.

“Bloom is not the key component [in a shade garden] — foliage color and texture will fill in for bloom to provide nonstop color,” she said.

Like its sunny garden counterpart, a shade garden can be counted on for bloom from May until October. It is the plant choice that will make the difference on the calendar.

The earliest shade bloomers include Lenten Rose (Helleborus orientalis), a glossy evergreen, and Majeste Lungwort (Pulmonaria, “Majeste”), which comes from the poorly named line once believed to cure lung ailments. Longwort Majeste has bluish-pink flower bells, leaves that are silver blotched with very little green showing, and is a short plant (only 8 to 12 inches at its tallest).

It works well under deciduous trees and along wooded pathways. While Majeste has bluish-pink flowers, new introductions are constantly expanding the choices in leaf coloring.

Seasonal suggestions — May and June bloomers — from Ms Duthie included Foamy Bells (x Huecherella, “Burnished Bronze”), which offer burgundy color; White Nancy Lamium (Lamium maculatum, “White Nancy”), silvery-white; Beedham’s Lamium (Lamium maculatum,”‘Beedham’s White”), yellow; and Labrador Violent(Viola labradorica), purple-tunged.

Although not a favorite plant, Ms Duthie even had hosta as a last resort suggestion.

With its blooms in July and August, Gold Standard Hosta (Hosta fortunei, “Gold Standard”) blooms with a yellow center and Piedmont Gold Hosta (Hosta “Piedmont Gold”) is overall yellow; while Halcyon Hosta (Hosta, “Halcyon”) is a chalky blue that can be counted of for late summer, right into September.

And finally, for nonstop foliage color (not flowers) all season long, Ms Duthie suggests European Ginger (Asarum europaeum), a glossy evergreen; Christmas Fern (Polystichum acrostichoides), also a glossy evergreen; Japanese “Painted” Fern (Athyrium nipponicum, “Pictum”), which is variegated; or Bowles Sedge Grass (Carex elata, “Bowles Golden”) or Japanese Combed Grass (Hakonechloa macra, “Aureola”), both of which are yellow. Bowles Sedge will also be left alone by deer and rabbits.

A garden will never fully develop in one season. It takes time to experiment with plant sizes and colors, not to mention the temperaments of different plants.

Be patient. Have fun. Be open-minded.

“Plan your progression for happy returns,” said The Gifted Gardener.