NARGS: Good Rock Garden Plants

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Part II: Good Rock Garden Plants

by NARGS contributors

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

Papaver alpinum [pah-pah-ver al-pie-num]. The Alpine Poppy graces the early summer garden with solitary 1¹/2" flowers of white, yellow, red, orange and pink on 8" stems of fine silvery foliage. Requires gravelly, moist soil and a mulch of stone chips. Short-lived but self-sows. Native to the high mountains of the Old World. Zones 4-7.

Penstemon cardwellii 'Roseus' [pen-steh-mon card-well-ee-eye]. Large tubular rose-pink flowers on an 8" spike above dark, finely cut evergreen leaves. Provide a rocky north-facing site with gritty soil and this native of moderate elevations in the Cascade and Coast ranges of Oregon will flower in late spring. Zones 4-8.

Penstemon hirsutus 'Pygmaeus' [her-soo-tus pig-may-us]. From June to August violet-blue 1" long tubular flowers with white lip cover the upper part of 6" wooly spikes of lance-shaped, purplish leaves. From Tennessee to Virginia and north into Canada. Zones 3-8.

Penstemon pinifolius [pin-eh-foh-lee-us]. Scarlet trumpets throughout the summer crown a 6" bush of needle-like, evergreen foliage. Well-drained, lean, gravelly soil in full sun is required for this southwestern U.S. native. Zones 4-8.

Petrorhagia saxifraga [pet-row-ray-jee-ah saks-if-rah-gah]. (syn. Tunica saxifraga). Small pink flowers in masses cover this 8" spreading mound in summer. Well-drained rock garden soil in full sun satisfies this European native. Zone 4.

Phlox divaricata [floks dye-veh-rih-kah-tah]. Wild Blue Phlox bears clusters of fragrant 1¹/2" light blue to lavender or white flowers from April to June. Enjoys rich garden soil in full sun to part shade. Slugs in the Northwest love it. Native from Louisiana to Canada. Zones 2-9.

Phlox 'Millstream Jupiter'. Good blue-violet flowers and long-needled foliage mark this hybrid of P. subulata and P. bifida from Linc Foster's Millstream garden. Best in full sun at the front of the border or spreading over rocks. Zones 3-8.

Phlox stolonifera [stoh-lon-if-er-ah]. Blue, purple, pink or white flowers appear in April-May on an 8" creeping plant. Takes any good garden soil rich in humus in full to light shade. Does not like competition. Native from northern Georgia into Pennsylvania. Zones 2-8.

Phlox subulata 'Schneewittchen' [sub-you-lah-tah shnay-vit-chen]. It sports enchanting-but-small snow-white flowers on a 3" mound of needled foliage. Excellent performer in full sun to part shade in good garden soil. Looks wonderful creeping around rocks or in a wall. Zones 3-8.

Polemonium reptans [poh-leh-moh-nee-um rep-tans]. This version of Jacob's Ladder has clusters of light blue, bell-shaped flowers on 12-18" stems over delicate compound leaves in spring. Provide rich woodland soil in light to moderate shade. While safe in its native area east of the Mississippi, it is fodder for slugs in the Northwest. Zones 2-8.

Polystichum tsus-sinense [pol-lih-stik-um sue-seh-nen-see]. Holly Fern. Evergreen 6-12" triangular fronds with distinctive black veins and holly-like tips. Small neat growth. Likes well-drained loam and takes morning or late afternoon sun. Japan and China. Zones 6-9.

Potentilla neumanniana 'Orange Flame' [poh-ten-till-ah new-man-ee-ah-nah]. (syn. Potentilla verna nana 'Orange Flame'). Numerous coin-like bright yellow flowers in summer on very short stems over dark green dwarf mounds of triangular leaves. Accepting of most soils in full sun. This cultivar forms clumps rather than spreading. Zones 4-8.

Potentilla tridentata [try-den-tah-tah]. Glossy dark green 3-part, 3-toothed leaves turn red in autumn. Clusters of dainty white flowers on 6-8" stems appear in late spring and summer. Rocky or sandy soil in full to part sun. From Canada south across the Midwest to the Atlantic and down into the mountains of Georgia. Zones 2-8. P. alba, though harder to find, is similar but longer blooming.

Primula japonica [prim-you-lah jah-pon-eh-ka]. This primrose, from Japan, is the "queen of the candelabras," with several named forms in white, pink and red shades. It should have part or full sun and damp soil. The flower stems, which appear in late May and June, have successive whorls of flowers, eventually reaching a height of 2'. It will benefit from an annual feeding with manure and bone meal when the plants go dormant in the fall. Zones 4-7.

Primula x juliana [times joo-lee-ah-nah]. (properly, P. x pruhoniciana). These hybrids are small plants with dark green, crinkly foliage and good-sized flowers. The small distinctive red-petioled leaf of P. juliae, one of the parents, is frequently retained in the hybrids. They need rich, well-drained soil in light shade. The best-known hybrid is 'Wanda', a floriferous variety with deep wine-red flowers in April. Zones 4-8.

Primula x polyantha [pol-lee-anth-ah]. This familiar garden primrose is the result of crossing P. veris, P. elatior and P. vulgaris. It forms large clumps about 10" high in April and May. The huge flowers are borne in large flat clusters on stems 8-15" high. Colors include all shades of yellow, red, pink, purple, blue, buff, and bronze. It wants a rich, deep soil, preferably on a slope or raised bed to provide essential drainage to the crown. Zones 3-8.

Primula sieboldii [see-bohl-dee-eye]. A Japanese woodlander and one of the easiest of the primroses. It spreads in mats of light green crinkly leaves about 3" high, that go dormant in mid-summer. The open umbels of up to ten flowers on 8-10" stalks appear in late spring. The individual flowers, frilled at the edges and often snow-flake-like, are in shades of dark pink to white. In any reasonably good soil in deep or light shade or part sun the rhizomes increase in size year after year just beneath the surface. Zones 4-8.

Primula vulgaris [vul-gahr-is]. The wild primrose of English hedge-rows and European mountains forms tuffets of rough dark green leaves with dark-eyed, pale yellow flowers, each on its own stalk carried just above the foliage. There are subspecies ingwerseniana with white flowers from Mt. Olympus in Greece, and ssp. sibthorpii with pale pink blooms from the Balkans. This primula also likes a rich well-drained soil in semi-shade. Zones 4-8.

Pulmonaria longifolia x saccharata [pull-moe-nah-ree-ah lon-jeh-fo-lee-ah times sa-kahr-ah-tah]. P. saccharata is the common Bethlehem Sage or Spotted Dog. The hybrid selection 'Roy Davidson' has long, dark green, narrow spotted leaves with pink flowers aging to blue in plants 1' x 1'. The small bell-like flowers make it one of the most useful plants for partially shaded gardens. All the lungworts revel in rich moist soil in either sun or shade. Zones 3-8.

Pulsatilla vulgaris [puhl-sah-till-ah vuhl-gah-ris]. (syn. Anemone pulsatilla). P. v. is from the lower reaches of the European Alps. It has finely cut leaves, grows 10" high and bears large purplish flowers in April and May, followed by ornamental, fuzzy seed heads. It should be planted in well-drained, limy soil of low fertility in a sunny or slightly shaded place. There are several good color forms ranging from white through lilac to stop light red. Anemone patens from northern Europe, northern Asia and North America from Illinois to Alaska is similar. Zones 3-8.

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
Papaver alpinum [pah-pah-ver al-pie-num]. The Alpine Poppy graces the early summer garden with solitary 1¹/2" flowers of white, yellow, red, orange and pink on 8" stems of fine silvery foliage. Requires gravelly, moist soil and a mulch of stone chips. Short-lived but self-sows. Native to the high mountains of the Old World. Zones 4-7.		Penstemon cardwellii 'Roseus' [pen-steh-mon card-well-ee-eye]. Large tubular rose-pink flowers on an 8" spike above dark, finely cut evergreen leaves. Provide a rocky north-facing site with gritty soil and this native of moderate elevations in the Cascade and Coast ranges of Oregon will flower in late spring. Zones 4-8.
Penstemon hirsutus 'Pygmaeus' [her-soo-tus pig-may-us]. From June to August violet-blue 1" long tubular flowers with white lip cover the upper part of 6" wooly spikes of lance-shaped, purplish leaves. From Tennessee to Virginia and north into Canada. Zones 3-8.		Penstemon pinifolius [pin-eh-foh-lee-us]. Scarlet trumpets throughout the summer crown a 6" bush of needle-like, evergreen foliage. Well-drained, lean, gravelly soil in full sun is required for this southwestern U.S. native. Zones 4-8.
Petrorhagia saxifraga [pet-row-ray-jee-ah saks-if-rah-gah]. (syn. Tunica saxifraga). Small pink flowers in masses cover this 8" spreading mound in summer. Well-drained rock garden soil in full sun satisfies this European native. Zone 4.		Phlox divaricata [floks dye-veh-rih-kah-tah]. Wild Blue Phlox bears clusters of fragrant 1¹/2" light blue to lavender or white flowers from April to June. Enjoys rich garden soil in full sun to part shade. Slugs in the Northwest love it. Native from Louisiana to Canada. Zones 2-9.

Phlox 'Millstream Jupiter'. Good blue-violet flowers and long-needled foliage mark this hybrid of P. subulata and P. bifida from Linc Foster's Millstream garden. Best in full sun at the front of the border or spreading over rocks. Zones 3-8.
Phlox stolonifera [stoh-lon-if-er-ah]. Blue, purple, pink or white flowers appear in April-May on an 8" creeping plant. Takes any good garden soil rich in humus in full to light shade. Does not like competition. Native from northern Georgia into Pennsylvania. Zones 2-8.
Phlox subulata 'Schneewittchen' [sub-you-lah-tah shnay-vit-chen]. It sports enchanting-but-small snow-white flowers on a 3" mound of needled foliage. Excellent performer in full sun to part shade in good garden soil. Looks wonderful creeping around rocks or in a wall. Zones 3-8.		Polemonium reptans [poh-leh-moh-nee-um rep-tans]. This version of Jacob's Ladder has clusters of light blue, bell-shaped flowers on 12-18" stems over delicate compound leaves in spring. Provide rich woodland soil in light to moderate shade. While safe in its native area east of the Mississippi, it is fodder for slugs in the Northwest. Zones 2-8.
Polystichum tsus-sinense [pol-lih-stik-um sue-seh-nen-see]. Holly Fern. Evergreen 6-12" triangular fronds with distinctive black veins and holly-like tips. Small neat growth. Likes well-drained loam and takes morning or late afternoon sun. Japan and China. Zones 6-9.		Potentilla neumanniana 'Orange Flame' [poh-ten-till-ah new-man-ee-ah-nah]. (syn. Potentilla verna nana 'Orange Flame'). Numerous coin-like bright yellow flowers in summer on very short stems over dark green dwarf mounds of triangular leaves. Accepting of most soils in full sun. This cultivar forms clumps rather than spreading. Zones 4-8.
Potentilla tridentata [try-den-tah-tah]. Glossy dark green 3-part, 3-toothed leaves turn red in autumn. Clusters of dainty white flowers on 6-8" stems appear in late spring and summer. Rocky or sandy soil in full to part sun. From Canada south across the Midwest to the Atlantic and down into the mountains of Georgia. Zones 2-8. P. alba, though harder to find, is similar but longer blooming.		Primula japonica [prim-you-lah jah-pon-eh-ka]. This primrose, from Japan, is the "queen of the candelabras," with several named forms in white, pink and red shades. It should have part or full sun and damp soil. The flower stems, which appear in late May and June, have successive whorls of flowers, eventually reaching a height of 2'. It will benefit from an annual feeding with manure and bone meal when the plants go dormant in the fall. Zones 4-7.
Primula x juliana [times joo-lee-ah-nah]. (properly, P. x pruhoniciana). These hybrids are small plants with dark green, crinkly foliage and good-sized flowers. The small distinctive red-petioled leaf of P. juliae, one of the parents, is frequently retained in the hybrids. They need rich, well-drained soil in light shade. The best-known hybrid is 'Wanda', a floriferous variety with deep wine-red flowers in April. Zones 4-8.		Primula x polyantha [pol-lee-anth-ah]. This familiar garden primrose is the result of crossing P. veris, P. elatior and P. vulgaris. It forms large clumps about 10" high in April and May. The huge flowers are borne in large flat clusters on stems 8-15" high. Colors include all shades of yellow, red, pink, purple, blue, buff, and bronze. It wants a rich, deep soil, preferably on a slope or raised bed to provide essential drainage to the crown. Zones 3-8.
Primula sieboldii [see-bohl-dee-eye]. A Japanese woodlander and one of the easiest of the primroses. It spreads in mats of light green crinkly leaves about 3" high, that go dormant in mid-summer. The open umbels of up to ten flowers on 8-10" stalks appear in late spring. The individual flowers, frilled at the edges and often snow-flake-like, are in shades of dark pink to white. In any reasonably good soil in deep or light shade or part sun the rhizomes increase in size year after year just beneath the surface. Zones 4-8.		Primula vulgaris [vul-gahr-is]. The wild primrose of English hedge-rows and European mountains forms tuffets of rough dark green leaves with dark-eyed, pale yellow flowers, each on its own stalk carried just above the foliage. There are subspecies ingwerseniana with white flowers from Mt. Olympus in Greece, and ssp. sibthorpii with pale pink blooms from the Balkans. This primula also likes a rich well-drained soil in semi-shade. Zones 4-8.
Pulmonaria longifolia x saccharata [pull-moe-nah-ree-ah lon-jeh-fo-lee-ah times sa-kahr-ah-tah]. P. saccharata is the common Bethlehem Sage or Spotted Dog. The hybrid selection 'Roy Davidson' has long, dark green, narrow spotted leaves with pink flowers aging to blue in plants 1' x 1'. The small bell-like flowers make it one of the most useful plants for partially shaded gardens. All the lungworts revel in rich moist soil in either sun or shade. Zones 3-8.		Pulsatilla vulgaris [puhl-sah-till-ah vuhl-gah-ris]. (syn. Anemone pulsatilla). P. v. is from the lower reaches of the European Alps. It has finely cut leaves, grows 10" high and bears large purplish flowers in April and May, followed by ornamental, fuzzy seed heads. It should be planted in well-drained, limy soil of low fertility in a sunny or slightly shaded place. There are several good color forms ranging from white through lilac to stop light red. Anemone patens from northern Europe, northern Asia and North America from Illinois to Alaska is similar. Zones 3-8.
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

Part II: Good Rock Garden Plants