There are about 28 species of annuals, biennial, and perennial some which are evergreen or semi evergreen, in this genus. They occur in a wide range of habitats in Europe, Northern Afria, Asia and Mexico. They have clusters of simple leaves either basal tufts or arranged alternately on stems. In spring and summer, they produce blue or white flowers, similar to forget-me-nots (Myosotis) each with a short tube and 5 spreading lobes, usually in terminal racemes or cymes, sometime held singly. Most are shade loving, and used as a groundcover in a border, or rock or woodland garden. Use O. linifolia in an annual border or for cut flowers.

Most of the perennials thrive in moist, moderately fertile, humus rich soil in shade or partial shade. Carefully divide perennial in early spring.

Very prone to slugs and snails.

O. cappadocica ‘Starry Eyes’ – This clump forming, underground rhizomatous, evergreen perennial grows 6-10″ tall and 10-16″ wide. It produces oval to heart shaped, pointed, finely hairy, mid green, basal leaves, to 4″ long. In early spring it bears loose terminal racemes, to 10″ long, of 3-12, purple-blue flowers with a central white stripe on each petal, each to 1/2″ across.

Zones 6-8

There are about 28 species of annuals, biennial, and perennial some which are evergreen or semi evergreen, in this genus. They occur in a wide range of habitats in Europe, Northern Afria, Asia and Mexico. They have clusters of simple leaves either basal tufts or arranged alternately on stems. In spring and summer, they produce blue or white flowers, similar to forget-me-nots (Myosotis) each with a short tube and 5 spreading lobes, usually in terminal racemes or cymes, sometime held singly. Most are shade loving, and used as a groundcover in a border, or rock or woodland garden. Use O. linifolia in an annual border or for cut flowers.

Most of the perennials thrive in moist, moderately fertile, humus rich soil in shade or partial shade. Carefully divide perennial in early spring.

Very prone to slugs and snails.

O. cappadocica – This clump forming, underground rhizomatous, evergreen perennial from Turkey grows 6-10″ tall and 10-16″ wide. It produces oval to heart shaped, pointed, finely hairy, mid green, basal leaves, to 4″ long. In early spring it bears loose terminal racemes, to 10″ long, of 3-12 white eyed, purple-blue flowers, each to 1/4″ across.

Zones 6-8

There are about 28 species of annuals, biennial, and perennial some which are evergreen or semi evergreen, in this genus. They occur in a wide range of habitats in Europe, Northern Afria, Asia and Mexico. They have clusters of simple leaves either basal tufts or arranged alternately on stems. In spring and summer, they produce blue or white flowers, similar to forget-me-nots (Myosotis) each with a short tube and 5 spreading lobes, usually in terminal racemes or cymes, sometime held singly. Most are shade loving, and used as a groundcover in a border, or rock or woodland garden. Use O. linifolia in an annual border or for cut flowers.

Most of the perennials thrive in moist, moderately fertile, humus rich soil in shade or partial shade. Carefully divide perennial in early spring.

Very prone to slugs and snails.

O. cappadocica ‘Cherry Ingram’ – This vigorous, compact, clump forming, underground rhizomatous, evergreen perennial grows 6-10″ tall and 10-16″ wide. It produces oval to heart shaped, pointed, finely hairy, mid green, basal leaves, to 4″ long. In early spring it bears loose terminal racemes, to 10″ long, of 3-12 white eyed, purplish blue flowers, each to 1/2″ across.

Zones 6-8

There are about 100 species of hairless or softly hairy annuals and perennial, some becoming woody at the bases, in this genus. They occur on drier prairies and in woodland in Northern and Central America and Mexico. Most have slender, upright stems and produce opposite leaves, which may be either simple and smooth edged, pinnate, or palmate (either palmately lobed or divided, 3 palmate). Daisy like, pink or golden yellow, some bi-colored flowers are borne on long stalks, they are good for cut flowers (generally produced over a very long period in summer), and are attractive to bees. Grow in an annual, herbaceous, or mixed border. Some cultivars, though perennials, are grown as annuals, most flower freely in their first year from seed.

Grow in fertile, well drained soil in full sun or partial shade. Deadhead to prolong flowering. Support taller cultivars. Divide perennials in late winter or early spring. They dislike heavy clay but are tolerant of coastal region, poor, stony soil.

Prone to bacterial spot, rust, botrytis flower blight, aster yellows, powdery mildew, downy mildew, fungal spots, slugs and snails.

C. californica – This erect, branched, almost hairless annual from California, Southern Arizona and Northwestern Mexico grows 18″ tall and 9-12″ wide. It produces lance shaped, smooth edged to shallowly lobed, mostly basal, dark green leaves, to 6″ long. In summer it bears solitary yellow flowers, to 1 ½” across.

Hardiness

There is a sole species of erect to spreading basally branched, hairy annual in this genus. They occur from grasslands, desert margins, and chaparral in Western USA. It has almost stalkless, stem clasping, smooth edged, 3″ gray-green leaves, sometimes borne in small whorls. The leaves and young stems have a covering of fine hairs. It is grown for its short lived, 1″ diameter poppy like flowers, each with a central boss of flattened stamen filaments, borne in profusion where the climate is neither too hot nor too humid. Suitable for edging in an annual border and as massed plantings in a rock garden.

Grow this easily grown plant in very light, well drained soil in full sun.

P. californicus – This many branched, spreading annual found from California to Arizona and Utah grows 4-12″ tall and 10″ wide. It produces linear-oblong to lance shaped, densely hairy, strongly parallel veined, gray green leaves, to 3″ long. In spring it bears single, slender stemmed, 6 petaled, creamy yellow flowers, to 1″ across, great for naturalizing in a wildflower garden.

Zones 9-10

There are about 400-500 species of annuals, biennials, evergreen, semi evergreen, and deciduous perennial (some rhizomatous), and a few deciduous sub shrubs, within the Violacea family make up this genus.  They occur naturally in varied habitats worldwide, with the greatest concentrations of species in North America, The Andes, and Japan.  They have variable, smooth edged, usually kidney to heart shaped leaves with stipules.  Some species are rosette forming and are very similar to Sempervivums.  The mostly unscented flowers, are usually solitary, rarely paired.  Each flowers has 5 petals: a lower petal sometimes with a spur, two side petals, and two upward facing upper petals.  Most flower profusely over long periods in summer. And may self-seed freely and become a nuisance.

Many cultivars within the genus are informally referred to as garden pansies, violas, or violetta, they are a result of complex hybridization.  Garden pansies (V. x wittrockiana cultivars) are short lived perennials, with faintly scented or unscented, more or less rounded flowers often with patterned “faces”.  Violas, sometimes referred to as tufted pansies, are compact, tufted perennials with usually scented, more or less rounded, often patterned flowers with rays (lines in a deeper or contrasting color).  Violettas are similar to violas, but are even more compact, with small, sweetly fragrant, oval flowers, each with a central yellow mark and no rays.

The perennials and subshrubs are suitable for a rock garden, a scree bed, or the front of a border.  Treat garden pansies as annuals, biennials, or short lived perennials.  They are good for containers, some are suitable for bedding.  Others are winter or spring flowering, and are ideal for planting with spring flowering bulbs.

Grow in fertile, humus rich, moist but well drained soil in full sun or partial shade.  In a rock garden grow in poor to moderately fertile, gritty, sharply drained soil in full sun or partial shade, protect from winter moisture.  Divide perennial species in autumn or spring.

Prone to mosaic viruses, downy mildew, powdery mildew, crown rot, root rot, rust, gray mold (botrytis), spot anthracnose, and other fungal leaf spot, slugs and snails, aphids, and violet leaf midge.

Viola hybrida– This clump forming, short-lived annual grows 6-8” tall and wide.  It produces heart shaped leaves in a wide variety of colors.   Grow in any well-drained soil, in full sun to partial shade.  Excellent for borders, rock gardens, and containers or window boxes.

Zones 7-11

grows to 12-18inches tall with heavily veined leaves and produces many petalled flowers with button in the center

grow in partial shade to full sun