The Best Plants for Nantucket -July 2011

The wide selection of plants that do well here on Nantucket begs the question, “Which ones are the best?”

by: Hilary Newell

It set my mind spinning trying to define “best.” Plants serve so many purposes for us, it would be impossible to restrict the list so as to appeal to everyone’s desires. Annual or perennial? Sun or shade? Ornamental or purely practical? Trees and shrubs or herba- ceous perennials? Whatever the combination of criteria, though, it seems that feeling sat- isfaction with the process and the final prod- uct are the ultimate objectives in choosing what plants are best to grow.

My personal satisfaction increases when I am able to present something I have grown in a way that is pleasing to those around me. There. I said it. I want to be proud of what I grow, whether it’s because of overcoming a challenge to make something grow, or to be able to serve the most delicious, fresh meals with the food I have grown. Why else would anyone spend their resources planning, weeding, fencing, mulching, watering, feed- ing and harvesting? Is it to aim for first prize in the daffodil show? Is it to grow a zucchini that would feed a small country? Is it to have all-summer bloom? Is it to improve the value of your property? Or simply to enjoy Nantucket’s light sparkling on the vibrant colors in your garden? Whatever the reason for choosing plants to grow, the results seem to be measurable by degrees of beauty, ease of growing, quantity of harvest or just the number of oohs and ahhhs that are elicited. When I sat down to finally think about what plants are really best for Nantucket, it was mostly shrubs and a few perennials and bulbs that came to mind.

Wherever you are growing, it’s key to look at the native and volunteer plants that survive in your area. One of our natives, Viburnum dentatum, gives us some clues about what will grow well here. There are a few out- standing cultivars of viburnum that are exceptionally hardy and reliable. Viburnum carlesii, or Koreanspice viburnum, performs perfectly each year, blooming in late April and finishing around Mother’s Day, filling the yard (and the inside of the house if we are lucky enough to have a warm day) with its heady, sweet, spicy vanilla scent. A warm, sunny day makes the scent surround the entire house. The full-open blossoms are white, erupting from pinkish buds. The compact variety only grows to about four feet, but the standard grows six to eight feet tall. Maintenance is minimal (no dead- heading or pruning required) and the results are astounding. This particu- lar shrub scores high on the oohs and ahhhs scale. Viburnum plicatum tomentosum (doublefile viburnum) is another. This viburnum is not at all finicky about the site where it grows, thriving in either full sun or full shade. When choosing a site, though, keep in mind that the more sun it gets, the larger it will grow. Over the course of 10 years, a plant in full sun could be twice the size of its twin planted in the shade. I planted one in partial shade next to a fence, resulting in my having to trim the viburnum heavily every few years to keep it off the fence. The white flowers are held above the foliage, in two straight lines down either side of the stem. Individually sim- ilar to lace-cap hydrangea flowers, the blossoms appear to be lined up, mil- itary style, marching down the graceful stems. Occasional pruning is all that’s necessary to keep this outstanding shrub happy.

A few other shrubs rank right up there with the same ease and satisfaction. There are more than 100 varieties of buddleia (butterfly bush, summer lilac, orange eye) that are exceptionally easy to grow here on Nantucket. Given enough space, buddleias will perform, without fail, every year. The panicles range in size, depending on the variety, from about four inches to nearly a foot long, and the height can range from two feet for some newer hybrids to nearly 12 feet for some of the older varieties. Highly attractive to butterflies and moths, buddleias bloom for weeks and weeks and are exceptionally low-maintenance. Cold New England winters keep them in check, as they are considered noxious weeds in Oregon and Washington. Again, they will grow in a range of conditions, from full sun to part shade. Trimming off dead blossoms and selective shaping and pruning are helpful, but not required. Buddleia makes a great tall focal point all summer long.

Vitex agnus caste (chaste tree) is another flowering shrub, making its appearance some time in August. Labor Day usually finds the Vitex in full bloom, with bees busily collecting the pollen for late-summer honey. With hardiness zones shifting incrementally, Vitex, which is typically a zone 7 plant, seems to survive better and better each year. In zone 5, it died back to the ground each year, but here we only cut off a small amount of win- terkill. The true blue flowers glow in the late-summer light.

A “Best of Nantucket” article wouldn’t be complete without some mention of hydrangeas. Nikko Blue is a stunning icon of the island, but there are so many other worthy cultivars to point out. Hydrangea paniculata Limelight is an award-winning hardy shrub. Hailing from Holland, Limelight has bright chartreuse blooms in mid-summer that mature to rich deep pink in the autumn. Its color is great for blending with most other colors in the garden. The panicle is interesting in a dry or fresh bouquet, and it is very reliable. The flower heads are upright, and can reach 12 inches in diameter. There’s no need to monkey around with pH, as the bloom color is stable. Hydrangea arborescens Annabelle is one of my all-time favorites, and it blooms reliably even after a difficult winter. The brilliant white flower heads can reach 10 inches across, and each shrub can have hundreds of blos- soms. They do well in woodland shade or on the dry, shady side of a house. They are not to be fussed with, and are better left neglected. Hydrangea anomala subsp. petiolaris is one of the most carefree and successful climbers for here, too. Another exceptionally-reliable bloomer (unless you prune too late in the fall, as I did a few years ago) the climbing hydrangea is perfectly happy in full shade. The north side of a house is perfect. You don’t need any particular skill to prune correctly, just clip off the spent blossoms in late summer. The pure white flower is similar to a lace-cap, but with larger petals. It doesn’t need a trellis and doesn’t need to be tied up. It is vigorous, but not like wisteria which is destructive.

New Dawn roses seem to be synonymous with Nantucket. Postcards fea- ture thousands of pink blossoms rambling up the sides of the gray-shingled cottages. For this reason alone, they belong on the “Best Of ” list, but they are outstanding plants, with excellent reliability and dependable bloom. Their hardiness speaks volumes, and it might be for that reason that New Dawn is one of the most popular climbing roses in the world. Any plant that can survive on a roof through our winter deserves an award. Introduced in 1930, New Dawn is very vigorous and needs strong support, but is a breeze to maintain. A ladder and some pruners are all that are needed to keep it happy. Another plus for this rose, that is in turn good for Nantucket, is its disease resistance. The medium-green foliage stays clean all summer without any fun- gicide application.

Non-native Rosa rugosa has a place here on the island, but I don’t believe it is in your garden. While still being evaluated for its invasive potential, it has long since established itself over a large portion of Nantucket, probably pushing out other native plants. It does serve a purpose but it belongs only in one place: on the back side of a dune, keeping the sand from eroding away. A true survivor and drought-lover, Rosa rugosa can exist in pure sand and helps stabilize the dune below. I will admit that the some of the non-invasive hybrids like Blanc Double de Coubert, Therese Bugnet and Alba are suitable for home landscape use, though they are not on my top-10 list.

Cupressocyparis leylandii or Leyland cypress is an evergreen tree that is surprisingly versatile. As a specimen plant, it can fill up a large corner of a yard, or can be used as a hedge. It is very useful for screening, quickly cre- ating privacy in your yard. The Leyland is fast-growing and relatively deer- resistant, though I have observed some deer rubbing their antlers on it. Once it reaches a large-enough size, the deer usually leave it alone and it grows rapidly. Leyland cyprus will outgrow a small yard, but in a large landscape, it can be stunning.

The perennial-garden enthusiast has several options for growing their passion on Nantucket. Without a doubt, any member of the daffodil or narcissus family can be given the label “Best for Nantucket.” Each year, I attend the daffodil show and am challenged to grow more in my own yard. This year was no exception, but the challenge is even greater. With over 1,000 stems entered I saw varieties I had never seen before. The beauty of daffodils is there are so many types your garden can be in bloom with them for six weeks. When purchasing, note the bloom time on the packages, and get some for each bloom period: early spring, mid-spring or late spring. Two or three varieties in each period will prolong the time of blooming in your yard. The small, multi-headed Tete-a-Tete blooms first in my yard, along with hyacinths. Jack Snipe and Jetfire are two other early-bloomers. Our mid-spring bloomers are Dutch Master, Pink Parasol and Fortune. We also planted a mostly double mix around the bird bath a few years ago. I don’t know their names, but with about six varieties, the bloom time is stretched out for many weeks. Patches of doubles and Pheasant’s Eye are dotted around the edges of the woods, and are by far, the last to bloom. They are also the most fragrant of any that I have, so I look forward to them when the rest have all gone by. Anybody can grow daffodils, in just about any place. They require very little care and provide the hope of spring when the Grey Lady has served up the dreariest of winters.

Salvias as a group have all the qualities representing the “best of.” Salvias are the most resistant to deer-browse of any group of perennials. They are available in a wide variety of colors, from white through red and burgundy to the deepest of blues. The annual varieties are very long-blooming in

July and August, while the perennials tend to bloom later in the summer and through the fall. True blue Saliva uliginosa begins in mid-summer and blooms through the fall, while the purple-blue Salvia leucantha begins blooming in September and goes until frost. Sometimes we plant these in large containers that take the place of old, tired pots that have burned out by the end of August.

Aside from the short bloom time, peonies have it all. They require very lit- tle maintenance, they’re deer-resistant, and they happily return year after year. Vivid colors, extravagant blossoms and incredible fragrance welcome summer and are crowd-pleasers in the garden or on the table. Peonies are one of the best cut flowers you can grow. They elicit lots of oohs and ahhhs from non-gar- deners who don’t realize how easy they are to grow. Each year I lament that plant breeders should develop more varieties of peonies that bloom at differ- ent times so we can enjoy their impressive blossoms longer. I am now happy to report that this is indeed happening, though we have yet to vet them for reliability and care. Like the grower who says “I can’t say it’s not a perennial until I’ve killed it at least three times,” I can’t put these peony hybrids on a “Best Of ” list until I grow some successfully for at least three years.

There are plenty of other shrubs and perennials that may make a “Best Of ” list in your own yard. The north and south sides of the island often have very different weather conditions, and while we are all in the same USDA zone, microclimates exist all over the place. It’s worth trying some new plants every year. Breeders are creating new varieties all the time and every one of them dreams that their new hybrid or discovery will become a household name, or at least make it onto someone’s “Best Of ” list. O

Hilary Newell is the greenhouse production manager at Bartlett’s Ocean View Farm.

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