| My garden is on Fire Island, about 500 ft. from the beach, protected by a tall fence, and has almost pure, very acidic sand as a growing medium. I need to water (and the sprinklers/drip hoses are on timers, since it's a weekend house) and I do add peat moss, compost and hydrogel to the sand, along with osmocote (slow release fertilizer). Still, as spmimi above says, it's really just glorified sand and you need to find plants that tolerate or actually enjoy it. Through trial and error, I've found a lot that do. The limiting factor is not drought or salt as much as the soil texture (very coarse) and the pH (4.5 to 5.0). Other people haul in lots of loamy topsoil and have those wooden raised bed things, but I didn't want to play that game or suffer the expense and bother that goes with it. I thought nature, in her glorious variety, would provide plenty of choices for these conditions, and the old girl came through. These comments will only be helpful if your conditions are like mine. I'd do a pH test first thing. I've failed spectacularly with yarrow (Achillea), lavender, Russian sage (Perovskia), rudbeckia, gaillardia, echinacea, coreopsis, euphorbia, agastache, wall flowers and sea holly. Other things that sounded perfect, like sea lavender and sea kale, bombed. Austrian pine (Pinus nigra) gets too many diseases, as does Japanese black pine (Pinus thunbergii). Stay away from those. I'd also forego blue spruce (Picea pungens), since they really don't enjoy our climate. If you'd like a pine and your conditions are like mine, pitch pine (Pinus rigida) is the best. Japanese white pine (Pinus parviflora) and mugo pine (Pinus mugo) are also very good. When you are talking trees, it's good to have things that are guaranteed to succeed, since you don't want to replace them all the time like perennials and annuals. Black cherry (Prunus serotina), red cedar (Juniperus virginiana and almost every other kind of juniper), tupelo (Nyssa sylvatica), sassafras (Sassafras albidum), American holly (Ilex opaca), post oak (Quercus stellata), service berry (Amelanchier sp.) and red maple (Acer rubrum) are all native to the seashore area, some in dry places and some in wet. Be aware that black cherry is a messy tree and not good to place over driveways, streets or patios. But the birds sure enjoy them. I see willows and poplars around a lot, but they are also very messy trees, and short-lived. The cliche tree of all time, red-leaf Japanese maple, is frequently planted, but the leaves usually burn and they never look great. I've been delighted that evergreen southern magnolia (Magnolia grandiflora) does very well, but it's a good idea to get a hardy cultivar such as 'Edith Bogue' or 'Bracken's Brown Beauty'. Even if you don't want a tree, these are worth pruning and training flat and tying on to a fence, if such a garden task appeals to you. The leaves are stunning, as are the flowers, in June. I'm currently testing smoke tree (Cotinus coggygria) and it did well last year, but too early to tell long term. Moving on to shrubs, all the sumacs are excellent, as are the spiraeas, brooms (Cytisus), barberries (Berberris), blueberry (Vaccinium corymbosum), bay berry (Myrica pensylvanica), arrow-wood viburnum (Viburnum dentatum), butterfly bush (Buddleja davidii cultivars), chaste-tree (Vitex agnus-castus) and of course the shrubby, low juniper cultivars. I think that shore juniper (Juniperus conferta) from Japan is particularly handsome for a large-scale groundcover. I can get the shrub-type crape myrtles (Lagerstroemia) to flower, but only with a lot of compost and watering. I don't have space to list all the cultivars of the above shrubs, but remember that if you choose a colored-leaf cultivar, like spiraea (Spiraea japonica 'Gold Flame') or barberry (Berberris thunbergii 'Rosy Glow'), you can have vibrant color in your garden for months on end. On the island, everybody plants andromeda shrub (Pieris japonica) and barberry wherever deer browse. They will not touch them. But you asked about groundcovers. The best are the heaths (Erica carnea) and heathers (Calluna vulgaris). In a nutshell, heaths bloom in winter/early spring and heathers bloom in late summer. Get both. These all come in cultivars with green, gray, or more brightly colored foliage. They are evergreen and very drought tolerant. Your best bet if interested is to explore a mail order nursery listing on line, such as Rock Spray Nursery. Other great spreading groundcovers for sun are thymes (Thymus species and cultivars), moss phlox (Phlox subulata), wine leaf cinquefoil (Potentilla tridentata), Pussy toes (Antennaria dioica), dusty miller (Artemisia stelleriana), bear berry (Arctostaphylos uva-ursi), Sedum album and lily turf (Liriope muscari). Sedum lineare And Sedum acre are pests, beware. It's nice that virtually all ornamental grasses are happy. The only one that failed for me was Deschampsia. You can get very low ornamenal grasses, like blue fescue, or really tall ones, like the big Miscanthus and Panicum cultivars. Sedges look like grasses, but are not, and provide some gorgeous textures and colors (Carex hachijoensis 'Evergold'). I was surprised to find which perennials and biennials did well. Some reliables for me are foxgloves (Digitalis purpurea, D. x mertonensis, D. grandiflora, and the best, D. thapsii 'Spanish Peaks'). Thrift (Armeria cultivars) is excellent. Other reliables are rose campion (Lychnis coronaria), sedum 'Autumn Joy', spiderwort (Tradescantia virginiana) field daisy (Leucanthemum vulgare), some pinks (Dianthus 'Mountain Mist, 'Little Bobby', and D. arenarius), and most hardy geraniums like Geranium 'Rozanne', 'Orion', 'Ann Folkard' and G. sanguineum. I see many native goldenrods and asters blooming in the swales between the dunes in fall, but there are less every year because of the deer. The hardy mallows (Hibiscus moscheutos) are magificent in boggy places, wherever they are not being choked out by common reed (Phragmites australis). Daylilies are iris are possible, but remember that the closer the plant is to the wild form, the more vigor it has and the better to cope with tough conditions. Thus, the common roadside daylily (Hemerocallis fulva) and pale bearded iris (Iris pallida) are more successful than highly hybridized modern cultivars with huge flowers and unusual colors. This is where getting to know your neighbors and sharing old-fashioned plants that have proven their worth pays off. The suggestion of rugosa roses is excellent. These are widely regarded as having the best fragrance of all roses. I like some of the rugosa cultivars with better bloom and nicer habit such as 'Frau Dagmar Hartopp', 'Jens Munk', 'Therese Bugnet' and 'Henry Hudson'. All the traditional roses: hybrid teas, floribundas and grandifloras, as well as large-flowered climbers, are out of the question in sand. However, I've had great success with the old-fashioned rambler roses. They grow big, but the canes are very flexible and easy to wrap around railings, poles, trellises, etc. They are perfect for the seashore because they tend to get a lot of mildew disease inland. They only bloom once a year, but it lasts three to four glorious weeks in June/July and the bloom is far more abundant and dense than anything you can imagine. This is the kind of rose you see in pictures of Nantucket and Cape Cod on the white picket fences. They have names like 'Dorothy Perkins', 'American Pillar', 'Lady Gay', 'Francois Juranville', 'Gardenia', 'Alexander Girault' and others. You need to get them from a specialist rose nursery, easy to find online. A cute dwarf shrub rose with tiny double pink flowers that also blooms once a year is called 'Petite Pink Scotch'. Nice leaves, too. Everybody likes azaleas and rhododendrons. These are hard to grow in full sun, especially in sand. I've had no luck with the typical large-leaf rhododendrons. Much better luck with azaleas, especially if I give them some shade. The ones that do best tend to have small, evergreen leaves, like the Kurume types. Deciduous azaleas that do well are species native to our area and hybrids derived from them. A great one is Rhododendron atlanticum, which can tolerate a lot of sun and has incredibly fragrant white flowers. It's deciduous and likes dry sand (please water it, though!). A good native azalea for wetter places is Rhododendron viscosum, the so-called swamp honeysuckle. If you can find hybrids with one of these species in its ancestry, you are in business. I'll finish with a short list of successful annual flowers for acidic sand and sun: Gomphrena, Nicotiana, Cleome, Arctotis, Petunia, Zinna angustifolia, Lantana, Portulaca, Scaevola, Cuphea 'David Verity', and Salvia coccinea. Among the bulbs, the best are lilies (especially the tiger lily, Lilium lancifolium, and the brand new orien-pet types). Lilies are perennial, but you need to replant Dahlias every year. Dahlias are worth it since they do amazingly well in these conditions, as long as you give slow release fertilizer and water liberally. Dahlias provide the majority of flower color for me in August and September. A super, low-growing type of Dahlia that blends well with dwarf groundcovers is the Gallery series. Dwarf plants are always smart in a windy place. Another trick I use is to grow plants that don't like sand, such as tender geraniums, canna lilies, fuchsias, coleus, and most vegetables and herbs in large pots on the deck. With a good potting mix and drip irrigation on a timer, you can grow a huge variety of things. There are a million more things to tell you, but this is more than enough for now, right? As long as you keep at it, your garden will be absolutely gorgeous. Let us know how it's coming along, OK? |
