Oenothera
Evening primrose. The following are perennials prized for their fragile, silky, and often scented flowers in shades of yellow, pink or white that appear during the warmer months. The blossoms open widest in bright light and offer a strong splash of color in tough, rough places with full sun and moderate to infrequent water. Useful in combination with California poppies or other wildflowers in dry borders, meadows or rock gardens for a lovely display of delicate color. Hardiness varies. Southwestern North America to Mexico.
speciosa: Mexican evening primrose. Low growing perennial 12-18" high and spreading by short, underground rhizomes to several feet wide. Profuse 1-2" pink flowers with yellow centers appear from early spring through fall. This vigorous groundcover thrives with little or no care, and may be invasive if not controlled. Use as groundcover for dry slopes or parking lot strips. Hardy to below 0F.
speciosa ‘Siskiyou’: A compact, floriferous selection with paler pink flowers than the species.
‘Woodside White’: Nearly white flowers with a chartreuse eye open from pink buds and grow to 15" tall, slowly colonizing by underground stolons. Drought tolerant and durable, an occasional shearing improves the appearance of this cultivar.
Olea europaea ‘Little Ollie’
Common olive. A dwarf form of the evergreen olive tree, this selection is fruitless and reaches 3’ high with dense branching and tiny gray-green leaves. The smooth, gray trunk becomes gnarled and decorative with age. Tolerant of sun, heat, cold, drought and a wide range of soil types, ‘Little Ollie’ is useful as a lawn tree, on slopes, or as a specimen container plant. Periodic deep watering will encourage deep roots and increase drought tolerance. Hardy to 10F. Northwest Himalaya, Arabia.
Omphalodes cappadocica
Navelseed. A spreading perennial with creeping underground stems and loose sprays of flat, bright blue flowers held above tufts of oval-shaped, hairy, basal leaves. Plants reach 6-10" tall, spreading to 10" or more. Flowers heaviest in mid-spring with sporadic flowers year round in California gardens. Plant in shade or half sun in moist, but well-drained soil. Useful in woodland gardens or as a small-scale groundcover. Hardy to below 0F. Asia Minor.
‘Lilac Mist’: Pale lilac flowers.
‘Parisian Skies’: Sky blue flowers that oddly enough bring to mind fresh baguettes, fine wine and romance.
‘Starry Eyes’: To 10" and spreading, with lavender-blue flowers edged in white that have the appearance of fallen stars, especially when massed in deep shade.
Origanum
Oregano or Marjoram. Name derived from the Greek oros, meaning mountain, and ganos, meaning joy. Yet another plant with an extensive history of cultivation, this favored genus was harvested in Ancient Egypt for medicinal and culinary purposes. Comprised of subshrubs and perennial herbs with tight clusters of small flowers and pleasantly aromatic foliage, the genus offers many species suited to California gardens. Most are rhizomatous and mounding, though others form tight mats. Any of the following make an ideal choice for rock gardens, container plantings, borders, open banks or trailing over rocks and walls. Though not fussy about soil type, they usually prefer full sun and moderate to occasional water once established. Hardiness varies. Mediterranean mountains to East Asia.
heracleoticum ‘Greek Mountain’: Perennial herb to 2’ tall with an equal spread. Plants have soft green, aromatic foliage and form white flowers in summer. Use on banks and walls, trailing over rocks, and in kitchen gardens. Plants appreciate a slight trim after flowering. Hardy to 10F.
x hybridum: Tufted perennial to 10" tall with one-inch, downy, ovate, gray-green leaves. Pink, drooping flowers, borne singly or in threes, appear from late summer into autumn. Hardy to 10F.
x hybridum ‘Santa Cruz’: Smoky purple-pink flowers are held above the foliage on this cross between Origanum dictamnus and O. sipyleum. Hardy to 20F.
laevigatum: Sprawling, arching, deciduous plant 2-3’ tall with purple flowers in spring, summer and early autumn. The small, aromatic, dark green leaves are held on red stems that root at the joints. Use in dry gardens as groundcovers. Hardy to 10F. Turkey, Cyprus.
laevigatum ‘Hopley’s Purple’: Similar to the species, though slightly taller and with large heads of purplish-pink flowers. Small, pointed leaves are held on wiry stems with 14" flower spikes. Aggressive, but not invasive.
rotundifolium ‘Kent Beauty’: A prostrate perennial, 6-8" tall and spreading to 12". The trailing stems are clothed in aromatic, rounded leaves and end in short spikes of tubular, pale pink flowers with darker bracts in the summer. Use on a wall or ledge, or in hanging baskets. The leaves are bluish-green, and tinged with purple when new. Hardy to 10F. Eastern Mediterranean.
vulgare ‘Golden’: Prostrate culinary perennial with bright green gold-tinged foliage and violet-purple flowers. Plants reach 3" tall and spread to 12" across. Trim back after flowering to maintain a tidy form. Hardy to 0F. Europe.
‘Betty Rollins’: This selection forms a dense mat with crowded, dark green leaves and clusters of light pink flowers in summer. Hardy to 15F. Garden origin.
‘Jim’s Best’: A handsome gold and green variegated selection with a bolder appearance than many of the oreganos we grow. ‘Jim’s Best’ grows to less than 6" tall and spreads up to 12". Plants bloom in summer and fall. Hardy to 10F.
‘Variegatum’: Cream and green variegated form 12-16" tall.
‘White Anniversary’: Spreading, variegated selection to 5" tall and 18" across. The creamy yellow and green leaves are rounded and held on wiry stems. Pale mauve flowers appear in summer. Hardy to 0F.
Ornithostaphylos oppositifolia
Palo blanco. Erect, multi-branched evergreen shrub to 12’ with reddish-brown bark that peels in thin sheets to expose smooth, white or gray-green stems. The thick, linear leaves are shiny green above and pale green beneath, and the small, springtime flowers are urn-shaped, greenish-white and produced in drooping panicles from February to April. The fruit is attractive to birds. Plant in full sun and well-drained soil; plants are drought tolerant, but appearance is improved with occasional summer water. Hardy to 20F. San Diego County and Baja California.
Othonna capensis ‘Little Pickles’
Unusual trailing succulent with leaves that do perhaps resemble little pickles. These 2" succulent cylinders are pale blue-green and clustered along spreading stems. Bright yellow daisy-like flowers appear in summer, but for most plant enthusiasts the unusual foliage is gift enough. Plant in full sun in well-drained gritty soil and provide moderate water. Plants are marginally hardy but do not fare well when cold temperatures are combined with wet soils. Plant in hanging baskets, along dry stone walls, or in decorative containers to enjoy this odd little wonder. Hardy to 20F. South Africa.
Oxalis
Wood sorrel. A large genus of perennials that has been boo-hoed by many because of a few species that have become aggressive weeds in many parts of North America. Despite the bad press, many species in the genus are charming ornamentals that do well in the California garden. We offer the following two in hopes of proving this point. Hardiness and culture varies by species. Cosmopolitan.
crassipes ‘Alba’: Clump forming perennial to 12" with lush clover-like foliage and abundant white flowers through much of the year. The evergreen foliage has the slightest purple blush in cool weather and may benefit from a hard shearing every so often to maintain a full appearance. Plant in full sun in moisture-retentive, well-drained soil with moderate water. Hardy to 5F. South America.
oregana ‘Smith River’: Redwood sorrel. A lush-looking California native from the understory of Northern California’s redwood forests. This selection forms clumps of velvety green, clover-like leaves to 4" wide on stems 2-10" high. Delicate pink flowers appear in spring and sometimes fall. Plant in partial to deep shade and provide regular garden water. Plants creep slowly by rhizomes and colonies may drift from the original planting over the years. Outstanding in association with native ferns like Woodwardia fimbriata or Polystichum munitum, or with shrubs like Philadelphus lewisii or Myrica californica. Hardy to 0F. Washington to California.
Ozothamnus rosmarinifolius ‘Silver Jubilee’
Evergreen shrub to 6’ tall with an upright habit and handsome silvery-gray foliage. Rosemary-like foliage covers the upright branches and gives rise in early summer to clusters of rust-colored blooms. Plant in full sun in moisture-retentive, but well-drained soils. Moderate water. Hardy to 10F. Australia, Tasmania.
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