Who isn’t transfixed by an avenue of lime trees leading to the green shade of a sitting area, or by a path meandering through low ground covers and into a birch grove? What about the tightly shaped boxwoods that contrast so well with the soft, flowing plant around them? These are architectural plants—ones whose structures give the garden a strong sense of design. They might include deciduous trees with a branching structure that creates year-round interest, or evergreen shrubs whose flowers highlight soft, mounding foliage. Well-considered architectural plants can elevate a garden from ho-hum to “Oh my.” The best of them can replace garden art, serving as a focal point for a collection of plants that needs something extra.

Many architectural plants are large, but they don’t have to be. On the list that follows, I’ve included smaller plants for smaller gardens. Whatever the size of your landscape, be sure to keep these structural plants in scale with the rest of your garden. A sweep of plants in a large garden could fill a bed 10 or 20 feet wide, while in a small garden (or small garden bed), the sweep might be just 3 to 5 feet wide. Contrasting leaf textures and colors combine with structure to make these plants stand out. Architectural plants are important enough that I’m always looking for good ones to use alone or in combinations. Here are a few favorites that can work in a variety of situations.

‘Ivory Silk’ lilac

Name: Syringa reticulata ‘Ivory Silk’

Zones: 3–7

Size: 20 to 25 feet tall and 15 to 20 feet wide

Conditions: Full sun to light shade; average to moist, well-drained soil

‘Ivory Silk’ lilac gives the lie to the notion that architectural plants can’t include lilacs. Not your grandma’s lilac, ‘Ivory Silk’ raises the bar. Though it has the fragrant, creamy white flowers and soft, rounded green leaves that make lilacs so popular in spring, its sturdy, well-branched tree form and reddish bark ­also make a strong statement in the winter garden. ‘­Ivory Silk’ matures at 20 to 25 feet tall, so the wind easily moves its lovely lilac fragrance throughout the entire garden. It has few pest problems. Place it at the end of a path or in front of a dark background, where it will surely draw you into the garden to explore further.

‘Robust’ male fern

Name: Dryopteris × complexa ‘Robust’ (syn. Dryopteris filix-mas ‘Undulata Robusta’)

Zones: 4–9

Size: 3 to 4 feet tall and wide

Conditions: Partial to full shade; average to moist, well-drained soil rich in organic matter

‘Robust’ male fern will not be ignored in your garden. A stately fern growing up to 4 feet tall and wide, it gives a tropical feeling to shady beds. It can naturalize in woodlands, but it also looks good massed around groves of trees and as a base for rounded, smooth-textured shrubs. Rainy climates like mine don’t faze this plant, since it prefers moist soil all year long. Evergreen with thick, wavy-edged fronds, it grows fast and is pest free.

‘Evening Light’ Japanese snowbell

Name: Styrax japonicus ‘Evening Light’

Zones: 5–8

Size: 6 to 15 feet tall and 4 to 5 feet wide

Conditions: Full sun to light shade; consistently moist soil

‘Evening Light’ Japanese snowbell is a beautiful small tree. When it blooms in early summer, its dark purple foliage sets off its drooping, bell-shaped white flowers on dark stems. As summer wanes, the leaves turn yellow with purple edges, eventually dropping to reveal hundreds of seed pods on bare branches. The open structure of the tree stands out against the winter sky; plant some low, flowing grasses or loose-structured shrubs under it and you’ll have a bed that works every day of the year. It grows in sun or partial shade but looks best if it is kept out of the hot afternoon sun. With good moisture all year long, it will grow to 15 feet, and it requires little pruning.

Lemony Lace® elderberry

Name: Sambucus racemosa ‘SMNSRD4’

Zones: 3–7

Size: 3 to 5 feet tall and wide

Conditions: Full sun to partial shade; adaptable to most well-drained soils

Lemony Lace® is an exciting new elderberry. I’m not sure how a bright yellow-green can be subtle, but in this lovely layered shrub, it is. Dissected yellow foliage touched on the edges with burgundy will stop you in your tracks. Elderberry often has pink flowers, but the clustered white flowers on Lemony Lace® are easier to use in combinations. They appear before the leaves in spring. In autumn, birds feed on the red berries, but deer usually leave the plant alone. Prune early in the plant’s life for good winter structure. This medium-size shrub is happy in sun or partial shade. When centered in a planting bed, Lemony Lace® contrasts nicely with tall tree trunks or coniferous backgrounds.

Bowles’ golden sedge

Name: Carex elata ‘Aurea’

Zones: 5–9

Size: 18 to 30 inches tall and wide

Conditions: Partial to full shade; average to wet soil

Bowles’ golden sedge, a vibrant evergreen sedge, is a great plant to mass along a pathway or around a taller group of deciduous plants such as hydrangeas. It prefers filtered shade and good moisture but can take some drought. Its bright, yellow-green blades grow to 2-1/2 feet, with spikes of black flowers thrust above stiffer leaves. Bowles’ golden sedge has a subtler spike than yucca, but it makes an impressive statement in the landscape. Unlike Japanese forest grass (Hakonechloa macra, Zones 5–9), it is evergreen, and the extra advantage of good flowering gives it an edge.

‘Winter Gold’ winterberry

Name: Ilex verticillata ‘Winter Gold’

Zones: 4–8

Size: 5 to 8 feet tall and wide

Conditions: Full sun to partial shade; average to wet soil

Winterberry has been on my architectural plants list for many years, and now a new cultivar, ‘Winter Gold’, is making designers rethink the winter landscape. Striking pink-gold berries appear on ‘Winter Gold’ in late fall, mellowing to golden yellow as winter sets in. Clustered tightly on bare stems, they bring bright color and texture to a sleeping garden; think of honey-colored grassy foliage and golden berries in the low winter sun. These female plants will produce berries more abundantly if there’s a male winterberry tucked in nearby. A wide hardiness range and good tolerance to sun or partial shade make it broadly useful. Showcase winterberry in a group of wispy grasses or perennials that die back in winter.

‘Carol Mackie’ daphne

Name: Daphne × burkwoodii ‘Carol Mackie’

Zones: 5–8

Size: 3 feet tall and wide

Conditions: Partial shade; moist, rich, well-drained soil

‘Carol Mackie’ daphne is one of my favorites. Though considered semi-evergreen, it retains its leaves in my Zone 8 garden. Fragrant, small, pink-white flowers cover the plant in spring and usually repeat in fall. Its compact habit makes it an excellent focal point in a small shade bed, where its flowers and variegated leaves light things up. Because of its diminutive size, it could be planted in mass or individually in a perennial bed for winter interest. ‘Carol Mackie’ is adaptable enough to take poor soils and more sun than other daphnes. It’s easy to grow, and it doesn’t need much pruning to hold its shape.

‘Sunsation’ magnolia

Name: Magnolia × ‘Sunsation’

Zones: 5–8

Size: 20 to 25 feet tall and 8 to 10 feet wide

Conditions: Full sun to partial shade; moist, well-drained soil rich in organic matter

Magnolias are one of the many flowering trees that are integral to good garden design. ‘Sunsation’ magnolia is a recent cultivar, with amazing branching structure and even more amazing flowers that cover the tree from April to mid-May. Each petal on these large golden blossoms is marked with purple-red blush at its base—think sunrise on a branch. The tree’s upright, pyramidal habit rises to 20 or 25 feet, and it thrives in either sun or partial shade. Use it in the center of a garden bed, or as a focal point for an entry bed. ‘Sunsation’ magnolia grows best with regular watering.

You don’t need to be intimidated by the idea of architectural plants. Think of how a beautiful front door or a window that frames a view can enhance the structure of a house as a whole. Architectural plants will do the same thing in your garden. Their presence and structure help you appreciate all the wonderful color and texture around them. Easy to incorporate, these lovely plants will give you years of pleasure. Plan, plant, and enjoy!

The Art of Using Architectural Plants

Once you’ve chosen the right plant for that key spot in your garden, it’s important to get the details right. Here are a few things to consider.

1. Keep them separate.

These are focal points in the garden; make sure other plants don’t overwhelm or detract from them.

2. Keep them tidy.

Because they draw the eye, architectural plants should be consistently deadheaded and pruned.

3. Frame them right.

Think about the background and foreground when planting. These will change throughout the season, so you need to plan for it.

4. Keep site conditions appropriate.

All plants in the same area should grow well in the same conditions. Don’t try to use an architectural plant that wants a dry, sunny location in a shady, moist spot. Even if it looks good at first, its chances for long-term success are limited.

Susan Calhoun is the owner and principal designer at Plantswoman Design on Bainbridge Island, Washington.

Photos, except where noted: millettephotomedia.com

Illustrations: Elara Tanguy

Sources:

• Bluestone Perennials, Madison, OH; 800-852-5243; bluestoneperennials.com
• Dancing Oaks Nursery, Monmouth, OR; 503-838-6058; dancingoaks.com
• Nature Hills Nursery, Omaha, NE; 844-849-2966; naturehills.com
• Sooner Plant Farm, Park Hill, OK; 918-453-0771; soonerplantfarm.com
• White Flower Farm, Litchfield, CT; 800-503-9624; whiteflowerfarm.com