The phrase “coastal gardens” evokes a host of memorable images, billowing daisies flanking gray-shingled cottages, bright “dune roses” blooming against an ocean background, or pots of brilliant red geraniums on a wooden pier. North America has an abundance of coastal areas that are home to a wide array of coastal gardens.
The rewards of coastal gardening are many. So are the challenges. Weather can be dramatic and unpredictable. The wind is unrelenting in some locations, and occasionally ferocious. Plants close to the water may be pelted with salt spray. The soil tends to be either thin, rocky or sandy, with a notable lack of nutrients to support plants. Despite all that, flower lovers won’t be denied. The following are a few annual, perennial, and shrub suggestions for common coastal situations:
In summer, plant drought-tolerant annuals tolerant of salt spray that will provide a steady supply of flowers until the first frost strikes. Tall verbena (Verbena bonariensis) is perfect for this, with its tall wands of violet flowers, as is red salvia (Salvia coccinea), which has flowers in shades of red, white, or salmon pink. You might also consider colorful geraniums (Pelargonium hybrids) with beautiful foliage and flowers in bright shades that will tolerate coastal salt spray. (In climates with mild winters, Pelargoniums will survive as perennials.)
Portulaca or moss rose (Portulaca grandiflora) flowers last only one day, but the low-growing plants make up for that by producing new blooms each morning. Like the grandiflora species, ornamental Portulaca oleracea, also called “purslane”, or, less poetically, “little hogweed”, features the same coastal-garden-friendly traits: growing low, spreading, and producing colorful flowers. Grandifloras have slender, almost needle-like leaves, whereas oleraceas feature rounded, fleshy leaves.
Sweet alyssum (Lobularia maritima) is another seaside beauty with spreading mounds of sweetly scented flowers that are typically white but also come in shades of pink, lavender, and apricot. Plant them in containers or alongside taller annuals and perennials.
Windy sites call for low-growing plants. Think of flowering alpines or rock garden specimens. In the spring, perennial creepers like moss pink (Phlox subulata) and small spring bulbs like ‘Minnow’ daffodils (Narcissus ‘Minnow’) and grape hyacinths (Muscari armeniacum) work well. Those living in warmer climates can rely on African lilies (Agapanthus spp.) with their tall clumps of strap-like green leaves and tall wands of purple, lavender, or white flowers.
Later in the spring, the aptly named sea thrift (Armeria maritima) provides winsome pink or white flowerheads and also naturalizes nicely. It is also cold hardy, a bonus in cold weather climates with daunting winter winds.
Another mid- to late-spring bloomer available in a range of colors is ice plant (Delosperma spp.), a low grower with daisy-like flowers and creeping succulent foliage. There are many species with variable hardiness, but most thrive in coastal gardens.
Midsummer coastal perennials include blanket flower (Gaillardia x grandiflora), with their deep red and yellow blooms. And, if you love purple coneflowers (Echinacea purpurea) and their kin, you are in luck! These summer bloomers will thrive in lean coastal soil and are available in a wide variety of colors and sizes. They pair well with another drought-tolerant, mid-border plant, yarrow (Achillea millifolium). Colors range from white through to yellow, gold, terra cotta, pink and red. The foliage is delicate and fern-like.
Later in summer, Montauk daisies (Nipponathemum nipponicum) keep the daisy show going, bearing big, yellow-centered daisies on 2- to 4-foot plants. Montauks are mid-border flowers that tend to have ungainly “legs” after the first year, so be sure to prune them back to 1 foot in the spring to maintain bushier growth and denser fall flowering. Plant lower-growing species in front of them.
Numerous species and varieties of sedum (Sedum spp.) or stonecrop (Sempervivum spp.), now all the rage in horticultural circles, provide flowers and other visual interest in summer and fall. Stonecrop flowers are not usually dramatic, but they are attractive as they sprawl along the ground.
For a taller and showier succulent, try a Hylotelephium, formerly part of the Sedum genus. The best known is the dusty-rose-flowered ‘Autumn Joy’, which grows about 18 to 24 inches tall and blooms in late summer or fall. Its flattened flowerheads are also excellent for drying.
Coastal Flowering Shrubs
Many beautiful garden roses are simply too delicate for coastal situations, however, anyone who has ever vacationed on the Atlantic coast has probably seen the roses people call “dune roses” or “beach roses”. This tough, reliable rose is Rosa rugosa, which originates from Japan but has naturalized across many North American coastal regions. Rugosas feature five-petaled blooms in white, pink or dark rose, and wrinkled or “rugose” green leaves. The stems are extremely prickly. After the blossoms fade, rugosas develop large, tomato-like hips that are both decorative and edible. Leaving them on the plants provides additional visual interest and food for birds and small animals.
Another common coastal shrub is shrubby cinquefoil (Potentilla fruticosa). In summer, it produces loads of yellow flowers on bushy plants that are tolerant of wind and salt. White and orange-flowered cultivars also exist.
Planting Coastal Flowers
For exposed areas subject to almost constant wind, trees or lines of tall shrubs can act as effective windbreaks to improve gardening but may be hard to establish. Another option is a sturdy fence or wall, but these can be inappropriate to a site or vulnerable to weather damage. Your best bet is to look at what other gardeners in your area have successfully established as windbreaks and follow suit.
When challenged with sandy or rocky coastal soil, amend beds with good soil or amendments, to keep moisture from draining away so quickly. Start by filling those growing spaces with Fafard Premium Topsoil, which will provide much-needed nourishment to your hungry plants, and finish off with an ample amount of Fafard Premium Natural & Organic Compost. Another option is to grow your coastal plants in containers or raised beds filled with Fafard Ultra Outdoor Planting Mix.
When planting your coastal plants, start with good-size plants and install them in spring, so that they have ample time to acclimate to their surroundings before winter weather sets in.
There are many other flowers fit for coastal conditions. When it comes to selecting flowering plants for your unique coastal garden, the best advice is to look at nearby properties and see what does well. Ask managers of local garden centers and nurseries for expert opinions on the flowering plants that sell best in your particular area. The oldest rule of thumb—“right plant, right place” is especially apt in coastal gardening.