Enhance your design with plants that thrive in harsh environments
Long a standard in the arid West and high-desert regions such as the Rockies, rock gardens have become increasingly popular throughout the country. A rock garden, also known as an alpine garden or rockery, incorporates stones and boulders with dwarf shrubs and low-growing or creeping plants. Traditional rock gardens are planted at high altitudes where they must withstand the rigors of heat, high winds, and drought.
Nowadays, you’re just as likely to find a rock garden in southern Connecticut as in southern California. Both pretty and practical, rock gardens offer an opportunity to accent underutilized areas of a landscape, add native plantings and manage trouble spots such as hillsides.
“One of the most common reasons landscapers install a rock garden is to eliminate higher-maintenance planting beds or replace turf,” says Jeff Gibson, landscape business manager at Ball Horticultural Company.
A rock garden may integrate the entire landscape or serve as an accent piece. The planting medium typically is sandy, rocky, and almost soilless. While traditional rock-garden plants are alpine or sub-alpine species such as columbines or lupines, many other plants actually do well in rock gardens.
“Common annuals and bedding plants provide an extra show of color all season long that true rock gardens usually only offer in spring, fall, or after a rain,” Gibson says.
Plants that work in rock gardens also do well in other harsh environments such as on hillsides, in the crevices along a stonewall or path, or along curbs. Try out a few of these hardy plants for your rock gardens and other tough-to-fill spaces.
Annuals
GoldDust Mecardonia, Proven WinnersGoldDust Mecardonia (Mecardonia hybrid)
Tiny green leaves with bright yellow flowers that bloom from May to October on a trailing habit. No deadheading necessary. Tolerates heat. Grows 5 inches tall and 20 inches wide.
- Hardy to USDA zones 10 to 11
- Full sun
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Moss Rose, Ball Horticultural CompanyMoss Rose (Portulaca grandiflora)
Low-growing, tolerant of heat and cold. Comes in an array of vivid colors, including fuchsia, deep red, orange, white, yellow, and variegated. New Happy Trails series has bigger flowers and good spread. Grows 6 to 9 inches tall and 14 to 18 inches wide.
- Hardy to USDA zones 2 to 11
- Full sun
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Silver Falls Dichondra, Ball Horticultural CompanySilver Falls Dichondra (Dichondra argentea)
Dense almost metallic silvery-green foliage on silver stems. Vigorous grower that creeps well as a groundcover or cascades over rocks. Withstands heat and drought. Grows 2 to 3 inches tall and 48 inches wide.
- Hardy to USDA zones 9 to 11
- Part sun to sun
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Shrubs
Bangle Genista, Proven WinnersBangle Genista (Genista lydia)
Heavily flowering, low-mounding deciduous bush boasts showy yellow flowers in spring. Attractive texture even when not blooming. Heat and drought tolerant. Grows 24 inches tall and wide.
- Hardy to USDA zones 4 to 9
- Sun
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Bepo Austrian Pine, MonroviaBepo Austrian Pine (Pinus nigra ‘Pierrick Bregeon’)
Dense shrub with glossy green color and spherical form. Compact habitat. Doesn’t brown out like Mugo pine in winter. Grows 3 feet tall to 4 feet wide.
- Hardy to USDA zones 4 to 8
- Full sun
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Good Vibrations Gold Juniper, Proven WinnersGood Vibrations Gold Juniper (Juniperus horizontalis)
Unlike other junipers, this one is soft to the touch. Three-season color: Chartreuse in spring, changes to bright yellow then orange in fall. Spreading, horizontal habit. Grows 18 inches tall and 9 feet wide.
- Hardy to USDA zones 4 to 9
- Full sun
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Perennials
All Gold Japanese Forest Grass, MonroviaAll Gold Japanese Forest Grass (Hakonechloa macra ‘All Gold’)
Dramatic golden foliage looks like tiny bamboo plants. Clumping habit. Grows 18 inches tall and wide.
- Hardy to USDA zones 4 to 9
- Part sun
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Curious Orange Monkey Flower, MonroviaCurious Orange Monkey Flower (Mimulus aurantiacus ‘Mimapri’)
New tropical hybrid with long-lasting orange flowers and glossy evergreen foliage. Grows naturally on slopes. Heavy bloomer. Grows 12 to 18 inches tall and 18 inches wide.
- Hardy to USDA zones 9 to 11
- Part sun to full sun
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Pinks/ Dianthus, Ball Horticultural CompanyPinks/ Dianthus (Dianthus various)
Tolerates high light and cool nights of traditional rock garden settings. Many different colors including dark pink, purple, and rose. New EverLast series has double blooms and longer bloom period. New Fruit Punch series has double, fragrant blossoms with patterned petals.
- Hardy to USDA zones 4 to 9
- Part sun to sun
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Succulents
Blue Spruce Sedum, Ball Horticultural CompanyBlue Spruce Sedum (Sedum reflexum ‘Blue Spruce’)
Bluish color looks like tiny blue spruce trees. Low-growing and spreading habit. Grows 6 to 10 inches high and 10 to 12 inches wide.
- Hardy to USDA zones 3 to 11
- Sun
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Garnet Brocade Sedum, Proven WinnersGarnet Brocade Sedum (Sedum (Hytolephium) hybrid ‘Garbro’)
Burgundy foliage and flowers. Long bloom season August through October. Upright habit. Attracts butterflies and hummingbirds. Grows to 16 inches tall and wide.
- Hardy to USDA zones 3 to 11
- Sun
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Pure Joy Stonecrop, Proven WinnersPure Joy Stonecrop (Sedum hybrid ‘Pure Joy’)
New variety has light green leaves and pinkish-purple flowers and seed heads. Forms low rounded mound. Grows to one foot tall and 20 inches wide.
- Hardy to USDA zones 3 to 9
- Sun
