Despite mild winters, selecting plants for a coastal garden can be difficult since the soil is usually very sandy, free draining, and may have a high pH. On top of that, the groundwater is frequently salty and marine winds carry a fine mist of salt-laden water that gets deposited on plant leaves. This combination of desiccating factors in coastal gardens can severely stress a landscape plant growing in seaside conditions. Similar salt-related gardening issues may occur if you plant in the drainage path of a salt-treated road or garden in salty desert soil. Keep in mind there are salt tolerant perennial plants that can thrive in these coastal garden conditions!
Read More About Salt Tolerant Plants
When we say "salt" we are referring primarily to sodium chloride, aka table salt. There are other salts in the world, but this is the one that most vexes gardeners. Why is salt so bad? There are three main reasons; 1. Salt causes plants to lose water; 2. Salt can interfere with plant nutrient absorption; 3. Salt can interfere with plant metabolism. Osmosis is easy enough to understand, but how do these other mechanisms work?
How does salt interfere with plant nutrient absorption? -- Plant roots absorb a variety of dissolved mineral salts from the soil. Too much salt in the soil can interfere with the availability and absorption of vital mineral salts due to ion charge imbalances, competitive inhibition of absorption, unbalanced root absorption, and disruption of the internal osmotic balance of the root cells.
How does salt interfere with plant metabolism? -- If plants have too much salt in their tissues, it can interfere with the cells' biochemistry, making the cell less efficient and less productive. Salt tolerant perennial plants have adjusted their metabolic chemistry to run more efficiently in the presence of high salt levels.
For these reasons, salt tolerant plants do much better in haline environments than their non-salt adapted cousins. Salt adapted perennials are what coastal gardeners should plant in their exposed beach landscapes. As a general rule of thumb, coastal native plants and desert plants tend to be salt tolerant plants. Scientists have a word for the most extreme salt tolerant plants - halophytes. True halophytes are the kings of the salt tolerant plants and can even drink seawater. Most salt-adapted garden perennials are not true halophytes, but they are still better than most other perennials. Some people further divide salt tolerant or salt resistant plants into "very salt tolerant or resistant", "moderately salt tolerant" and "mildly salt tolerant" groups, but our list below lumps them all together.
In addition to selecting salt tolerant plants, gardeners can practice a few cultivation techniques to improve the performance of their plants in a coastal environment. 1. Amend the soil with plenty of compost to increase its water holding capacity; 2. Water deeply to flush salts out of the root zone; 3. Build a wind break, fence or berm to reduce salt spray; 4. Do a soil test to determine if you need to adjust your soil pH. Good soil pH levels can improve a plants ability to absorb mineral nutrients despite the presence of salt.
When you are ready to buy salt tolerant plants for your desert or coastal garden, check out our online list of salt tolerant plants for sale below. The following index is a list of salt tolerant perennials that we grow here at Plant Delights Nursery. All plant groups are well represented...sun perennials, shade perennials, ornamental grasses, flowering perennials, foliage plants, ferns and palm trees.
Editor's Note - Those of you affected by superstorm Sandy in late 2012 have plenty of first hand experience with which plants tolerate salt water and which do not. We have heard from some of our customers who had gardens that were flooded with salt water by the storm. Some salt tolerant survivors include :
Please send us you own best solt tolerant plants and share with us your Sandy survivor stories at firstname.lastname@example.org.
Since 1988, Plant Delights Nursery has been the choice of serious gardeners and plant collectors looking for the best and rarest perennial plants. We are pleased to have received the Perennial Plant Association Retail Award in 2011, the American Horticulture Society Commercial Award in 2002, and to have been selected as one of the Best Mail Order Plant Nurseries - Garden Design Magazine 2010. Welcome to our family of plant lovers!
Anthea yarrow is a 1993 introduction...a discovery by the late Alan Bloom of England, who found it growing in a patch of Achillea 'Moonshine'. Achillea 'Anblo', marketed under the equally strange name 'Anthea', is a noticeable improvement over most of the yarrows we have tried...it actually survives here without trying to take over the garden. The basal rosette of cutleaf silvery foliage is topped in late spring with very erect 30" stalks, holding nice flower clusters of light butter yellow. This is a great addition to the softer colored parts of the border. Pot Size: 3.5" (24 fl. oz/709.77 ml)
We've tried many yarrows through the years and most have struggled through our hot humid summers, with the exception of Achillea 'Strawberry Seduction'. This Achillea millefolium hybrid (possibly with Achillea clypeolata) was selected in 2001 by Holland's Michiel Zwaan, who bred it from the Achillea Summer Pastels seed series. Achillea 'Strawberry Seduction' is a long-flowering selection that begins flowering in June with strong 2' tall well-branched stems, topped with clusters of colorfast red flowers, highlighted with small yellow centers. I've experienced strawberry reductions before, but admit that I find the imagery of a strawberry seduction...berry interesting. Pot Size: 3.5" (24 fl. oz/709.77 ml)
Not to be confused with the alien fighters of a similar name, Agapanthus 'Back in Black' is a new Lily-of-the-Nile from Holland's Piet Zonneveld. In late summer this 2005 introduction produces dark green flower scapes from the strap-like green foliage which age to black. The 2' tall flower scapes are topped with flower heads of very dark blue-purple flowers...quite striking and a favorite of hummingbirds. This is patented as an Agapanthus africanus selection, but being an open pollinated seedling, this species assignment is highly suspect. Pot Size: 3.5" (24 fl. oz/709.77 ml)
Agapanthus 'Bressingham Blue' is a 1972 introduction selected by the late plantsman Alan Bloom of the UK's Bressingham Gardens. Agapanthus 'Bressingham Blue' is a seedling selection from thousands of plants of the famous Headbourne hybrids. The clump of narrow, green, winter-deciduous leaves is topped, starting in late June (NC), with 30" stalks ending in 4.5" round flower heads of dark blue-violet flowers. Agapanthus 'Bressingham Blue' has been a vigorous, outstanding cultivar in our trials. Pot Size: 3.5" (24 fl. oz/709.77 ml)
(Patent 7303 expired) From California's Archie Amate comes this 1990 introduction, a phenomenally vigorous evergreen (in mild climates) Lily-of-the-Nile that makes a fast-growing 3' tall clump of green strap-like leaves, topped in midsummer with hummingbird-attracting dark blue-violet (RHS 93A), 8" wide flower heads on 50" tall stems. Pot Size: 3.5" (24 fl. oz/709.77 ml)
(Patent 7297 expired) Agapanthus 'Ellamae'...now there's a plant with a good southern name! From California's Archie Amate comes this 1990 introduction, a monstrous and vigorous lily-of-the-Nile that makes a large clump of green strap-like leaves, topped in midsummer with dark blue-violet umbels of flowers on Jack and the Beanstalk-like 66" tall stems...butterflies not included. Pot Size: 3.5" (24 fl. oz/709.77 ml)
This fully deciduous South African agapanthus species can be found in open meadows in the Drakensberg and surrounding mountain ranges. The clumps of strap-like green leaves are topped in July with 2' tall spikes of dark purple-black pendulous flowers in July...a very nice lily-of-the-Nile selection that is also a favorite hummingbird flower. Pot Size: 3.5" (24 fl. oz/709.77 ml)
Agapanthus 'Stevie's Wonder' is an introduction from California's Emerissa Gardens that I picked up on a West Coast swing many years ago...as much for the name as anything else. Over the years, this has been the star in our agapanthus trials, both for winter hardiness, deer-resistance, and outstanding flowering. The 2.5' to 3' tall (over 6' tall in the Pacific Northwest) spikes are topped with 4" ball-shaped heads composed of rich blue-violet, hummingbird-attracting flowers. I think you will find Agapanthus 'Stevie's Wonder' a superb garden-worthy clone, sure to be the sunshine of your life. We'll get yours on the way...signed, sealed, delivered. Pot Size: 3.5" (24 fl. oz/709.77 ml)
Thanks to Barrie Coate for setting us straight on the origin of this great agapanthus. When Barrie was director of the Saratoga Horticultural Foundation, he selected this gem from thousands of open pollinated seedlings of the deciduous Agapanthus 'Mood Indigo'. The resulting evergreen selection (only to 28 degrees F) is a dynamite lily-of-the-Nile with the typical strap-like foliage to 24" tall. Through late summer, the huge clumps of Agapanthus 'Storm Cloud' foliage are topped with giant, magnificent, hummingbird-friendly flower heads of bluish-purple on very sturdy stalks to 4' tall...WOW! Pot Size: 3.5" (24 fl. oz/709.77 ml)
From Kees de Jong of Holland comes an amazing agapanthus that appeared in his cut flower field of blue Agapanthus africanus. The deciduous (evergreen in mild climates), 1.5" wide green foliage makes a 2' wide clump, topped in midsummer with 30" stalks of huge 10" flower heads of up to 80 pure white flowers...a hummingbird favorite. It took Barry Bonds years of steroid use to get a head this large...Agapanthus 'White Heaven' has consistently tested clean. Pot Size: 3.5" (24 fl. oz/709.77 ml)
When my friend Gert Fortgens of Arboretum Trompenburg in Holland told me about his cross of the North American native Agastache foeniculum with the Korean Agastache rugosa, the offspring sounded too good to be true. However, after trialing Agastache 'Blue Fortune' in our dry garden, I consider it one of the finest new perennials in years! In spring, the strong new stalks shoot upward to 3' tall, clothed with fuzzy, licorice-scented fragrant leaves. From early spring through summer, the stems are topped with hundreds of large bottlebrush, blue-lavender flowers that attract a stunning array of pollinators, including hummingbirds! Agastache 'Blue Fortune' needs an open, well-drained site for best performance. Pot Size: 3.5" (24 fl. oz/709.77 ml)
This Terra Nova introduction is one of the first of the brightly-colored agastache hybrids to survive our NC summers. Agastache 'Cotton Candy' forms a 2' tall x 3' wide drought-tolerant clump of upright green stems, each clothed in small, but very minty-fragranced leaves. From spring through fall, the stems are topped with dense clusters of small pink flowers emerging from the dark pink-tipped calyces. Agastache 'Cotton Candy' is a magnet for attracting both butterflies and hummingbirds...we recommend a flight control tower within a 100' radius. Good drainage is essential for long-term survivability. Pot Size: 3.5" (24 fl. oz/709.77 ml)
Agastache foeniculum 'Get Riehl' comes from an early 1990s trip when I visited Iowa City plantsman, Frank Riehl. Sharing a love of native habitats, Frank took me to a nearby prairie remnant where I first saw anise hyssop growing in the wild. Those cutting-grown plants have remained in our garden for over two decades, so we decided that it was time to share. The deciduous Agastache foeniculum 'Get Riehl' makes a wispy upright clump of angular branched stems, topped from early summer through September with 6" terminal soft lavender flowers. Agastache foeniculum is also grown for its wonderfully fragrant licorice-scented foliage. Anise hyssop has long been prized for its medicinal value to cure everything from coughs to diarrhea. Bees also use anise hyssop to make a lovely flavored honey. In the garden, good drainage seems to be the key to persistence. Pot Size: 3.5" (24 fl. oz/709.77 ml)
We purchased this lovely form of Agave americana in 2005 from a grower in Thailand, but unfortunately it came without a valid cultivar name, so we've named it Agave americana 'Marshmallow Cream'. Agave 'Marshmallow Cream' has a much wider and shorter leaf than the typical Agave americana 'Marginata', which is more common in the trade. Agave americana 'Marshmallow Cream' also makes a much more elegant plant in the ground as well as in a container. Since it isn't winter hardy for us, we can only guess about a mature size, but we would expect 5' tall x 8' wide. Quantities are very limited. Pot Size: 3.5" (24 fl. oz/709.77 ml)
This beautiful, but slowly offsetting selection of the Mexican Agave americana makes a 2' tall x 3' wide clump, with each wide blue leaf highlighted with a wide central stripe of white. Agave americana 'Mediopicta Alba' is often used as a specimen container plant by gardeners in colder zones. Because of the leaf layer arrangement, Agave americana 'Mediopicta Alba' is one of the few variegated agave that cannot be successfully tissue cultured. Pot Size: 3.5" (24 fl. oz/709.77 ml)
I was fortunate to see this amazing, un-agave-looking agave in the wild near Monterrey, Mexico, where it precariously hangs off lightly shaded, high cliffs. Eventually spreading to 2' wide, the easy-to-grow, user-friendly Agave bracteosa resembles large, gray-green spiders with NO spines. We recommend that Agave bracteosa be planted on a slight slope to duplicate the great drainage they receive in the wild. After 2-4 years, Agave bracteosa will begin to form offsets and, when they mature, each clump will produce an amazing 5-7' tall flower spike that resembles a giant yellow bottlebrush! Pot Size: 3.5" (24 fl. oz/709.77 ml)
It was lust at first sight when I saw Agave bracteosa 'Monterrey Frost' in California's San Diego Botanic Garden. This rare form of the northern Mexican Agave bracteosa has been passed along in California collectors' circles for more than a decade, but is rarely available to the general public. The frozen squid-like architectural rosette of sandpapery green foliage is edged with a perfect creamy-white margin, eventually producing a 1' tall x 18" wide variegated specimen that will offset sporadically after it matures. Agave bracteosa actually enjoys part shade, which also keeps the white edge from scorching. The white edge reduces its winter-hardiness, so where this isn't reliably hardy, Agave 'Monterrey Frost' makes a stunning unarmed container specimen. With great age, your Agave 'Monterrey Frost' will flower with lovely fragrant yellow blooms that attract hummingbirds. Pot Size: 3.5" (24 fl. oz/709.77 ml)
We haven't been able to track down the origin of this splendid hardy century plant, but we now feel confident that it is a hybrid with Agave salmiana. Our seven-year-old patch has produced 2' tall x 3.5' wide rosettes that offset quite fast. The 9" wide, flat, blue-green, deeply-lobed leaves are particularly architectural. Because of the somewhat scabrous leaf back, we wonder if Agave scabra might be the baby daddy, but then Agave cupreata looks like a candidate also. Pot Size: 3.5" (24 fl. oz/709.77 ml)
Available 6-6-2013Agave 'Desert Diamond' is the latest Hans Hansen introduction...a wide edged sport of Agave 'Kissho Kan'. Compared to its parent, Agave 'Desert Diamond' is slightly slower growing due to the extra white in the leaf, but will eventually make a 15" tall x 18" wide, sparsely offsetting variegated rosette. Agave 'Desert Diamond' is a stunning plant, especially in a container for the summer patio. Pot Size: 3.5" (24 fl. oz/709.77 ml)
This stunning selection of the tropical Agave desmettiana comes from Joe Hoak of Hoak's Nursery in south Florida. Agave 'Joe Hoak' makes a stunning specimen plant with wide, pliable, glaucous grey leaves, each bordered in creamy white, which is in turn surrounded by a dark green edge. Many people consider this the most striking agave cultivar in commerce. Pot Size: 3.5" (24 fl. oz/709.77 ml)