Name: Aeonium spp. Size: 6-20 inches tall and wide Zones: 10-11 Top Picks: Zwartkop pinwheel plant (A. arboreum ‘Zwartkop’) has purplish black leaves at the tips of 2-foot-tall woody stems. Kiwi aeonium (A. haworthii ‘Kiwi’) has medium green leaves edged in red and gold. It is sometimes sold as ‘Tricolor’. Name: Sempervivum spp. Size: 3-6 inches tall and wide Zones: 4-8 Top Picks: Common hen-and-chicks (S. tectorum) comes in many outstanding cultivars with colors ranging from blue green to the fiery-red ‘Sunset’. Cobweb hen-and-chicks (S. arachnoideum) gets its name from the mat of white hairs that covers its leaves. Hairy hen-and-chicks (S. ciliosum) also has white hairs covering its stiff, densely packed leaves. Octopus hen-and-chicks (S. octopodes) develops offsets at the end of runners several inches long, which makes it resemble the arms of an octopus. Name: Campanula spp. Size: 4-12 inches tall; 4-24 inches wide Zones: 4-7 Top Picks: Blue Clips Carpathian bellflower (C. carpatica ‘Blue Clips’) and its sister variety ‘White Clips’ are clump formers that bloom much of the summer with upturned cup-shape flowers. Fairies thimbles (C. cochleariifolia) is a slowly spreading creeper with dangling white, blue, or lavender flowers. Dalmatian bellflower (C. portenschlagiana) bears bluish-purple blooms in early summer on a tidy groundcover plant. Birch Hybrid campanula (C. ‘Birch Hybrid’) blooms all summer long if deadheaded. Name: Lychnis viscaria Size: 12-18 inches tall and wide Zones: 4-8 Top Picks: ‘Splendens Plena’ is a double-flowered form that’s evergreen in warm climates. Name: Aubrieta deltoidea Size: 2-8 inches tall; 4-24 inches wide Zones: 5-7 Top Picks: ‘Bressingham Pink’ has double pink flowers. ‘Royal Velvet’ bears large purple blooms. ‘Hartswood Purple’ produces violet flowers. Name: Aurinia saxatilis Size: 6-15 inches tall; 12-18 inches wide Zones: 3-7 Top Picks: ‘Citrina’ bears lemon yellow flowers. ‘Compacta’ is a semidwarf form that remains under 10 inches tall. Name: Dianthus spp. Size: 4-18 inches tall and wide Zones: 3-10 Top Picks: Firewitch dianthus (D. gratianopolitanus ‘Firewitch’) bears magenta-pink blooms in spring, with sporadic rebloom in late summer on plants that reach 15 inches tall. Tiny Rubies dianthus (D. gratianopolitanus ‘Tiny Rubies’) grows 4 inches tall and has deep pink diminutive blooms. La Bourboule Pink dianthus (D. gratianopolitanus ‘La Bourboule Pink’) looks similar, with compact foliage less than 2 inches tall but with slightly larger pink blooms. Arctic Fire dianthus (D. deltoides ‘Arctic Fire’) is a mat-forming groundcover with white flowers marked in red and pink. Name: Alchemilla alpina Size: 3-5 inches tall; 4-18 inches wide Zones: 3-7 Name: Allium spp. Size: 6-12 inches tall and wide Zones: 4-8 Top Picks: A. cyathophorum var. farreri has thin, grassy green foliage and develops loose clusters of nodding purple flowers in early summer on plants 1 foot tall. Millenium allium (A. ‘Millenium’) offers gray-green foliage to 1 foot tall and 2-inch-diameter balls of lavender flowers in late summer. Name: Aloe spp. Size: 2-12 inches tall and wide Zones: 10-11 Top Picks: Torch plant (A. aristata) forms a dense clump of lance-shape leaves with toothed edges and bands of soft white spines. It grows only 5 inches tall. Hayworth aloe (A. hayworthioides) has warty gray-green leaves, reaching just 3 inches tall. Partridge-breast aloe (A. variegata) has deep green v-shape leaves splashed with bands of silvery white. It grows up to 1 foot tall. Name: Arabis spp. Size: 4-6 inches tall; 4-12 inches wide Zones: 4-7 Top Picks: Variegated wall rock cress (A. caucasica ‘Variegata’) is a mat-former with white flowers in spring and green foliage with yellowish leaf margins. It is slightly less vigorous than the plain species. Spring Charm rock cress (A. blepharophylla ‘Spring Charm’) has loose rosettes of green leaves and produces pinkish-purple blooms in spring. Name: Armeria spp. Size: 2-8 inches tall and wide Zones: 3-9 Top Picks: Sea thrift (A. maritima) features grassy foliage and 8-inch stems topped with flowers; it is the most widely available species. ‘Alba’ has white flowers. ‘Ruby Glow’ shows off deep pink blooms. ‘Dusseldorf Pride’ bears rose pink blossoms. Juniper-leaved thrift (A. juniperifolia) forms a tight hummock of spiny green leaves only 2 inches tall. Name: Cyclamen spp. Size: 2-5 inches tall and wide Zones: 5-9 Top Picks: C. hederifolium has ivy-shape leaves and bears fragrant pink flowers in autumn. C. coum blooms in winter or early spring with white, pink, or carmine-red blooms. Name: Delosperma spp. Size: 2-8 inches tall; 12-24 inches wide Zones: 5-10 Top Picks: Cooper’s hardy ice plant (D. cooperi) produces magenta pink blooms. Table Mountain hardy ice plant (D. cooperi ‘John Profitt’) is hardier than the species. Sutherland’s hardy ice plant (D. sutherlandii) has three-sided fleshy leaves and purplish pink blooms. Name: Echeveria spp. Size: 2-5 inches tall; 2-12 inches wide Zones: 9-10 Top Picks: Elegant echeveria (E. elegans) has silvery-green cupped leaves in a rosette up to 10 inches wide. E. ‘Perle von Nurnberg’ has pinkish-purple fleshy leaves in a rosette up to 10 inches across. E. prolifica forms miniature 1- to 2-inch-wide rosettes tightly packed together, creating a groundcover effect. E. shaviana has undulating silvery leaves in a rosette 6 inches in diameter. Name: Gasteria spp. Size: 2-6 inches tall and wide Zones: 9-10 Top Picks: Ox tongue (G. verrucosa) has 6-inch-long gray-green leaves heavily dotted with white bumps. It’s sometimes called warty aloe. Dwarf ox tongue (G. liliputana) is a smaller version of ox tongue, reaching only 2 to 3 inches tall. Name: Iris spp. Size: 4-6 inches tall; 4-6 inches wide Zones: Zones 5-8 Top Picks: Danford iris (I. danfordiae) has clear yellow flowers 2 inches in diameter. Reticulate iris (I. reticulata) bears fragrant purple, blue, or white blooms with yellow blotches. ‘Harmony’ offers deep blue flowers. ‘Purple Gem’ is a popular purple-blooming variety. Name: xGraptoveria spp. Size: 2-8 inches tall and wide Zones: 9-10 Top Picks: A Grim One graptoveria (xG. ‘A Grim One’) has lovely silvery pink rosettes tipped in pink. Tricolor graptoveria (xG. ‘Tricolor’) has thick leaves with colors ranging from silver to pink and purple. Name: Lewisia spp. Size: 6-12 inches tall; 8-16 inches wide Zones: 4-8 Top Picks: Cotyledon Hybrids lewisia (L. cotyledon) is a northern California species that readily hybridizes, creating a wide range of colors and plant forms. Bitterroot (L. rediviva) bears solitary pink or white blooms. Name: Linum flavum Size: 6-12 inches tall and wide Zones: 5-7 Top Picks: Compactum yellow flax (L. flavum ‘Compactum’) is the best choice for a trough garden because it grows only 6 inches tall. Name: Kalanchoe tomentosa Size: 6-24 inches tall and wide Zones: 10-11 Name: Paronychia kapela subsp. serpyllifolia Size: 1 inch tall; 6-24 inches wide Zones: 8-10 Name: Penstemon spp. Size: 4-16 inches tall; 6-16 inches wide Zones: 4-9 Top Picks: Dwarf hairy penstemon (P. hirsutus var. pygmaeus) is a spreading groundcover with fuzzy gray-green leaves and soft lavender flowers flushed with white. Foothills penstemon (P. heterophyllus) has bright blue or purple flowers on compact plants. Pineleaf penstemon (P. pinifolius) has needlelike foliage and bears tubular red-orange flowers. Name: Phlox subulata Size: 2-6 inches tall; 20 inches wide Zones: 3-8 Top Picks: ‘Candy Stripe’ has bicolored pink and white flowers. ‘Red Wings’ has rosy red flowers with dark red centers. ‘Emerald Blue’ has lavender-blue blooms. ‘May Snow’ has pure-white flowers. Name: Saxifraga spp. Size: 1-8 inches tall; 4-8 inches wide Zones: 1-8 Top Picks: Snail saxifrage (S. cochlearis) forms a dense cushion with spoon-shape leaves and white blooms in late spring or early summer. S. burseriana has narrow lance-shape gray-green leaves and bears white cup-shape flowers in early spring. Purple mountain saxifrage (S. oppositifolia) develops reddish-purple, pink, or white flowers in early summer on a creeping plant that reaches only 1 inch tall. Name: Sedum spp. Size: 2-6 inches tall; 4-12 inches wide Zones: 4-9 Top Picks: Kamchatka sedum (S. kamtschaticum) is a mounding plant to 4 inches tall. It bears yellow flowers that change to gold then reddish brown with age. S. lydium is a mat-forming evergreen groundcover with tightly clustered, rounded, reddish leaves. Cape Blanco sedum (S. spathulifolium ‘Cape Blanco’) has spoon-shaped silvery leaves and star-shaped yellow flowers. Name: Thymus spp. Size: 2-6 inches tall; 4-18 inches wide Zones: 4-9 Top Picks: Woolly thyme (T. pseudolanuginosus) grows only 1 inch tall, but spreads wide, with fuzzy silvery foliage. Minimus mother of thyme (T. serpyllum ‘Minimus’) forms compact mounds to 2 inches tall with pink flowers. flowers in early spring. Cilician thyme (T. cilicicus) offers lilac Name: Veronica spp. Size: 2-6 inches tall; 4-18 inches wide Zones: 4-8 Top Picks: Goldwell prostrate speedwell (V. prostrata ‘Goldwell’) has variegated green-and-gold foliage with purplish-blue flower spikes in spring. Heavenly Blue prostrate speedwell (V. prostrata ‘Heavenly Blue’) bears brilliant blue flowers in spring. Gentian speedwell (V. gentianoides) has cup-shape pale blue flowers in spring. Name: Sagina subulata Size: 1 inch tall; 4-8 inches wide Zones: 4-8 Top Picks: Irish moss thrives in rocky, well-drained soil. It has slender green leaves on a mat-forming plant with solitary white flowers. Scotch moss (S. subulata ‘Aurea’) is similar except its leaves are yellow green.
