A sense of adventure can yield big results with these spring plantings

IT’S SPRING, WHICH means it’s time for the next installment of Seattle Grows, a seasonal garden party game (that I made up). This year I’m reaching out to local garden pros, asking them to recommend plants that deserve a place in our Pacific Northwest gardens.

Richard Hartlage is the founding partner of Land Morphology, a Seattle landscape design firm that’s known for creating immersive spaces that connect people with their places. Hartlage was recently awarded the Mrs. Oakleigh Thorne Medal by the Garden Club of America for his outstanding work at the intersection of gardens, design and the built environment.

Hartlage has long used his personal garden, executed in bold color and with a playful sense of scale, for trialing plants and building materials. Fitting to his larger-than-life persona, more is always better. Which is immediately apparent when you arrive at his Montlake home, where a neatly clipped boxwood hedge artfully snakes through the sloping front garden, a disciplined garter of sorts for containing waves of blowsy plantings that shift with the seasons. With hundreds of purple softball-sized blooms appearing to float above the evergreen framework, giant alliums crawling with bees and other insect pollinators dominate the space in spring. Once the blooms fade, showy seed heads persist, bridging spring and summer plantings.

Over the years, Hartlage has found Allium ‘Globemaster’ to be the most dependable of the bulbous alliums. “Other allium bulbs must be bone dry during the summer months, so don’t count on them for more than a season or two if you irrigate,” he observes. “Globemaster tolerates average moisture — the secret to its adaptability.” While individual bulbs can be spendy, the designer says the plants increase well and turn into large clumps over time, justifying the initial investment.

Planting generous quantities of resilient bulbs is one thing, but a sure sign of an adventurous gardener is their willingness to take on garden projects that many of us might shy away from. At least that’s how I choose to think about the designer’s second recommendation — don’t say you haven’t been warned.

Hartlage recently began training a double white-flowering Lady Banks rose (Rosa banksiae ‘Alba Plena’) along the eastern facade of his house. When describing the plant’s vigor and size, the designer says Lady Banks is a “monster of a rose” that quickly grows 15 to 20 feet tall and thrives in full sun to partial shade. “Be ruthless and dominate her or she will become unruly in no time,” he warns. “A big ball of sisal twine and sharp shears are your friends with Lady Banks.”

A series of eye hooks placed at 18-inch intervals across a 10- by 20-foot area provides support for training the rose’s long, pliable thornless canes. Disease-free semievergreen foliage sets the stage for a singular seasonal display when profuse clusters of small flowers that smell sweetly of English violets arrive in late April. In addition to spectacularly generous blooms, Hartlage says Lady Banks rose is “very appealing to a broad range of insect pollinators and an excellent location for a nest if you are a robin.”

Provide adequate water in the first year after planting Lady Banks rose, but once established, Hartlage tells me the plant tolerates a good bit of drought, citing plants on Southern homesteads that are known to be more than 100 years old. Lady Banks rose comes in double- and single-flowering forms in white or pale yellow. Should you be interested in grooming your own floriferous seasonal marker, Hartlage says the double yellow form is commonly available at local retail nurseries. Gardeners looking for other forms should rely on mail-order sources such as Antique Rose Emporium (antiqueroseemporium.com).