Fragrance in the Garden
Fragrance in the garden is subjective: some gardeners like it and some don’t. For those who do and want to add it to their landscapes, there are many beautiful and sustainable plants that will provide fragrance in the garden. It is wonderful experience to walk by a mixed border, a patio planting or a foundation planting and sense the sweet fragrance of beautiful plants that you have selected to grace your landscape. With careful selection, fragrance can add another dimension to the landscape experience throughout the garden season.
Flowers and fragrance can begin as early as late winter with the Asian witchhazels (Hamamelis sp.). Hamamelis mollis or Chinese witchhazel is a large shrub or small tree, and when not pruned, can reach a height and width of 10-15 feet. Hardy to zone 5, the Chinese Witchhazel, usually blooms, depending on seasonal weather, in early February – late March, with short (5/8 inch) narrow, ribbon-like fragrant flowers. One of the most available, and fragrant Chinese witchhazels, is Hamamelis mollis ‘Pallida’, a Cary Ward winning plant which has very fragrant, pale yellow flowers. Another Asian witchhazel is Hamamelis x intermedia which represents hybrids between H. mollis and H. japonica. There are numerous cultivars of Hamamelis x intermedia with flower colors that range in various shades of yellow, red, orange and copper. These hybrids, also hardy to zone 5, may reach a height of 15 -20 feet when not pruned. They too would be considered a small tree or large shrub. One of the most admired and available is H. x intermedia ‘Arnold Promise’, an introduction from the Arnold Arboretum, Jamaica Plain, MA. ‘Arnold Promise’ has deep, yellow fragrant flowers surrounded at the base by a reddish calyx. There are many other available H. x intermedia cultivars: ‘Jelena’ with copper flowers; ‘Diane’ with red flowers, ‘Orange Beauty’ with orange flowers. Like the Chinese witch hazel, H. x intermedia cultivars usually bloom in early February – March, again depending on the season. An added bonus to these fabulous plants is that they have significant fall color ranging from brilliant yellow to orange-red, or burgundy, depending on the plant. Both H. mollis and H. x intermedia prefer growing in full sun, in an acid, well-drained organic soil.
Flowering in late March to early April, Abeliophyllum distichum or White forsythia is a relatively underused fragrant, flowering shrub. Abeliophyllum distichum has fragrant, four-petaled white flowers which are similar in shape to the yellow flowers of border forsythia. The white forsythia is not a true forsythia, but it is in the same Oleaceae family. White forsythia grows best in full sun and prefers well-drained soil. It is a multi-stemmed small shrub (5 ft W x 5 ft H) and looks best when pruned immediately after flowering to keep it tidy. Its main attribute is that it flowers in late winter with white fragrant flowers when few plants are blooming. It is hardy to Zone (4) 5.
Blooming usually in early May are two excellent viburnums known for their strong fragrance: Viburnum carlesii (Mayflower or Korean spice viburnum) and V. xburkwoodii (Burkwood viburnum). Both plants are hardy to zone 5, possibly 4, and prefer full sun and a well-drained organic soil. Pink to reddish pink in bud, the flowers open to white and form a round, snowball-like cluster 2-3 inches across, producing a sweet-spicy clove fragrance. There are several cultivars available and two of the best are Viburnum carlesii ‘Compactum’, a dwarf form of the species, growing slowly and compactly, and seldom requiring pruning, and V. x burkwoodii ‘Mohawk’, which has dark red flower buds, a strong fragrance and compact growth habit.
In late May to early June, a native plant, Chionanthus virginicus (Z4), or Whitefringetree, comes into bloom along with Syringa patula ‘Miss Kim’ (Z4) and Syringa meyeri (Meyer Lilac) (Z3). All three of these plants fill the garden with their fragrance. All grow best in full sun in a well-drained organic soil and can be used as specimen plants or in a mixed border. Syringa meyeri may also be used as a foundation plant. Chionanthus virginicus may grow 12 - 20 feet in height with equal width and is usually grown as a large shrub, although it can be grown as a small tree. The white 3/4 to 1 1/4 inch thin, fringe or ribbon-like flowers appear in panicles as the leaves begin to develop and the shrub looks like it is covered in white fringe. Syringa patula ‘Miss Kim’, a Cary Award winning plant, usually grows to a height of 8 - 9 feet with an equal width and its beautiful lilac- purple blossoms flower at the same time as Kousa dogwood (Cornus kousa), which makes an attractive combination. Syringa meyeri is a deciduous compact, mounding shrub (4-8 feet high and wide) with small leaves and produces dense terminals of pale lilac, fragrant flowers. The flowers of Syringa ‘Miss Kim’ and those of Syringa meyeri flower about two weeks later then the common lilac, Syringa vulgaris, and are resistant to powdery mildew and to lilac borer.
Continuing into June, fragrance in the garden is provided by the beautiful Lonicera xheckrottii ‘Gold Flame’ often referred to as an “everblooming honeysuckle” because of its’ long period of bloom beginning in June and continuing into the summer. This beautiful honeysuckle is a twining vine, 10-15 feet long and about 6 feet high. It has beautiful deep pink flower buds that open to two-inch long tubular, fragrant, pink flowers with a yellow center which are produced throughout the summer months and are attractive to hummingbirds and butterflies. Hardy to zone 5, Lonicera xheckrottii ‘Gold Flame’ grows best in full sun, in an organic well-drained soil and can be grown on a trellis, fence, stonewall or arbor. While Lonicera is a genus with many invasive members, Lonicera xheckrottii is not considered an invasive threat.
Complementing the flowering and fragrance of Lonicera xheckrottii ‘Gold Flame’ are the Weston Summer Azalea series. The late Ed Mezitt, of Weston Nurseries, Hopkinton, MA, bred many Rhododendrons including the Weston Hybrid Summer Azaleas. These summer flowering azaleas are hybrids of native species that are usually found along streams or wetland areas in their native habitat. Included in this mixed parentage are two native, fragrant, cold-hardy rhododendrons: Rhododendron viscosum or Swamp Azalea with spicy floral fragrance and the sweet fragrance of Rhododendron arborescens or Sweet Azalea. There are a number of cultivars in the Weston Hybrid Summer Azalea series and they are all excellent and underused. Several cultivars, ‘Pink and Sweet’, ‘Weston’s Innocence’, ‘Weston’s Lollipop’, and ‘Ribbon Candy’ begin bloom in mid-June and all have a sweet perfume fragrance and continue to flower for several weeks. Beginning bloom in late June – early July and continuing for several weeks is Azalea ‘Weston’s Sparkler’, a 2011 Cary Award which produces large, fragrant, deep pink, ruffled flowers which contrast nicely with the bluish-green leaves with their silver undersides. Also blooming around the same time are these other fragrant Weston azalea hybrids: ‘Weston’s Parade’ (pink), ‘Framingham’ peach-pink), ‘Weston’s Lemondrop’ (yellow), ‘Millennium’ (dark pink-red) and ‘Pennsylvania’ (clear pink), which is the latest to bloom. Many of the Weston Summer Azaleas may grow to six feet in 10 years with a mature height of twelve feet. To keep the plants compact, it is recommended that the new growth for next year’s flowers be cut back by half in June - July, before the plant flowers. Cutting the new growth by half at that time will expose the new flowers to better advantage and still allow time for the plant to set new flower buds on the regrowth for next year. These Summer Flowering Azaleas, hardy to zone 4, may be used in a mixed shrub border, in a woodland setting, or as a foundation plant and perform best in full sun, in a moisture-retentive, well-drained organic soil and benefit from a light mulch and watering during hot dry, summer weather. Butterflies and hummingbirds are attracted to these azaleas.
Blooming in late June early July and flowering for about four weeks, Clethra alnifolia, also known as Sweet Pepperbush or Summersweet Clethra, is a native landscape plant that fills the gardens with a strong, sweet fragrance. The small white flowers are arranged in upright racemes, appearing like short candles. There are also pink flowering forms and ‘Ruby Spice’, a Cary Award winning plant, is one of the best. Sweet Pepperbush grows to a height and width of 5-8 feet, is a suckering plant that forms colonies and is often used in shrub borders. Clethra alnifolia is hardy to zone 4, salt tolerant, site adaptable, grows in sun or partial shade and prefers a moist, organic soil, but is also drought tolerant.
A mass planting of Phlox paniculata (Garden or Border phlox) can fill the air with sweet fragrance beginning in June and continuing through most of the summer. Garden phlox is an herbaceous perennial that produces fragrant flowers in a range of colors from pure white, light pink, dark, purple, red, as well as some bicolor combinations. The plants grow in clumps 2-4 feet tall and wide and flowers are produced on straight upright stems. Phlox paniculata prefers growing in full sun, in an organic well-drained soil and is hardy to zone 3. When selecting Phlox paniculata for the garden, it is important to purchase disease resistant plants, as garden phlox is susceptible to a fungal disease called powdery mildew which usually will not kill the plant, but may make it unattractive depending on the season and the plant’s disease resistance. There are many disease resistant cultivars available like, ‘David’ (white), which are worth seeking out.
Actea (formerly Cimicifuga) simplex (Bugbane) is another herbaceous perennial that is somewhat underused. Actea simplex grows to a height of height of 3-4 feet high and 2-3 feet wide. It produces Astilbe or fern-like, compound divided, deep green foliage and 1-2 foot tall flower stems which arise above the foliage in late summer. The flowers resemble bottle brushes comprised of tiny, creamy-white, individual star-like flowers. The sweet fragrance from the flowers can fill the landscape. There are several cultivars with chocolate-brown-burgundy foliage such as ‘Brunette’, ‘Hillside Black Beauty’ and ‘James Compton’ that are worth seeking out, as the contrast of the white flowers against the dark foliage adds another dimension to the landscape. Hardy to zone 4, Actea simplex is easily grown in partial shade (morning sun and afternoon shade preferred), in an organic well-drained soil. This plant does need to be watered during hot, dry summers, as it may become scorched if the soil is allowed to dry out for too long.
These are but a few of the numerous choices of fragrant plants that are commercially available. Other plants that could be considered are: Malus sp. (crabapples), Convallaria majalis (Lily-of-the-valley), Valeriana officinalis (Garden heliotrope) and Hosta plantaginea, along with patio pots of non-hardy plants like jasmine and gardenia that can provide summer long fragrance and be overwintered indoors.