There are about 100 species of deciduous and evergreen shrubs and climbers, rarely trees, in this genus.  They occur in woodland in Eastern Asia and North and South America.  Grown mainly for their large, showy flower heads, many hydrangeas also have ornamental, flaky, peeling bark when mature, and attractive foliage with good autumn color.  The leaves are broadly to narrowly ovate, or lance shaped, toothed, and either opposite or in whorls of 3.  The flat, domed, or conical, terminal flower heads consist of corymbs or panicles of both tiny fertile flowers and larger sterile flowers with showy, 4 petal-like sepals.

Cultivars of H. macrophylla are divided into 2 groups: lacecaps have flattened flower heads with small fertile flowers in the centers, surrounded by larger sterile flowers, Hortensias (mophead hydrangeas) have nearly spherical flower heads of large sterile flowers.

The flower color of hydrangeas is affected by acidity or alkalinity of the soil.  Acidic soil containing aluminum produce blue flowers, soil with a pH greater than 6.0 produces reds and pink flowers.  White flowers are not affected by pH.  H. macrophylla can change their color by dressing with aluminum sulphate for blue and with lime for red.

Hydrangeas are useful for a range of garden site: they are excellent as specimen plants or in group plantings, in a shrub border, or in containers.  Climbers can be used to clothe a shaded wall or fence, or grow up tree trunks.  The flower heads may be dried for use in arrangements.

All parts of hydrangeas may cause mild stomach upset if ingested, contact with the foliage may aggravate skin allergies.

Grow in moist but well drained, moderately fertile, humus rich soil in sun or partial shade, provide shelter from cold, drying winds.  Most hydrangeas become chlorotic in alkaline soil.  Reblooming and/or remontant H. macrophylla produce flowers on current season’s wood so bloom it less likely to be lost to incorrect pruning or cold.

Prone to gray mold, slugs, powdery mildew, rust, ringspot virus, leaf spots, honey fungus, aphids, scale insects, and spider mites.

H. arborescens ‘Anna Belle’ – Snowhill Hydrangea – Smooth Hydrangea -.

Zones 4-9

There are about 100 species of deciduous and evergreen shrubs and climbers, rarely trees, in this genus.  They occur in woodland in Eastern Asia and North and South America.  Grown mainly for their large, showy flower heads, many hydrangeas also have ornamental, flaky, peeling bark when mature, and attractive foliage with good autumn color.  The leaves are broadly to narrowly ovate, or lance shaped, toothed, and either opposite or in whorls of 3.  The flat, domed, or conical, terminal flower heads consist of corymbs or panicles of both tiny fertile flowers and larger sterile flowers with showy, 4 petal-like sepals.

Cultivars of H. macrophylla are divided into 2 groups: lacecaps have flattened flower heads with small fertile flowers in the centers, surrounded by larger sterile flowers, Hortensias (mophead hydrangeas) have nearly spherical flower heads of large sterile flowers.

The flower color of hydrangeas is affected by acidity or alkalinity of the soil.  Acidic soil containing aluminum produce blue flowers, soil with a pH greater than 6.0 produces reds and pink flowers.  White flowers are not affected by pH.  H. macrophylla can change their color by dressing with aluminum sulphate for blue and with lime for red.

Hydrangeas are useful for a range of garden site: they are excellent as specimen plants or in group plantings, in a shrub border, or in containers.  Climbers can be used to clothe a shaded wall or fence, or grow up tree trunks.  The flower heads may be dried for use in arrangements.

All parts of hydrangeas may cause mild stomach upset if ingested, contact with the foliage may aggravate skin allergies.

Grow in moist but well drained, moderately fertile, humus rich soil in sun or partial shade, provide shelter from cold, drying winds.  Most hydrangeas become chlorotic in alkaline soil.  Reblooming and/or remontant H. macrophylla produce flowers on current season’s wood so bloom it less likely to be lost to incorrect pruning or cold.

Prone to gray mold, slugs, powdery mildew, rust, ringspot virus, leaf spots, honey fungus, aphids, scale insects, and spider mites.

H. quercifolia ‘Alice’  – Oakleaf hydrangea–

Zones 5-9

There are about 100 species of deciduous and evergreen shrubs and climbers, rarely trees, in this genus.  They occur in woodland in Eastern Asia and North and South America.  Grown mainly for their large, showy flower heads, many hydrangeas also have ornamental, flaky, peeling bark when mature, and attractive foliage with good autumn color.  The leaves are broadly to narrowly ovate, or lance shaped, toothed, and either opposite or in whorls of 3.  The flat, domed, or conical, terminal flower heads consist of corymbs or panicles of both tiny fertile flowers and larger sterile flowers with showy, 4 petal-like sepals.

Cultivars of H. macrophylla are divided into 2 groups: lacecaps have flattened flower heads with small fertile flowers in the centers, surrounded by larger sterile flowers, Hortensias (mophead hydrangeas) have nearly spherical flower heads of large sterile flowers.

The flower color of hydrangeas is affected by acidity or alkalinity of the soil.  Acidic soil containing aluminum produce blue flowers, soil with a pH greater than 6.0 produces reds and pink flowers.  White flowers are not affected by pH.  H. macrophylla can change their color by dressing with aluminum sulphate for blue and with lime for red.

Hydrangeas are useful for a range of garden site: they are excellent as specimen plants or in group plantings, in a shrub border, or in containers.  Climbers can be used to clothe a shaded wall or fence, or grow up tree trunks.  The flower heads may be dried for use in arrangements.

All parts of hydrangeas may cause mild stomach upset if ingested, contact with the foliage may aggravate skin allergies.

Grow in moist but well drained, moderately fertile, humus rich soil in sun or partial shade, provide shelter from cold, drying winds.  Most hydrangeas become chlorotic in alkaline soil.  Reblooming and/or remontant H. macrophylla produce flowers on current season’s wood so bloom it less likely to be lost to incorrect pruning or cold.

Prone to gray mold, slugs, powdery mildew, rust, ringspot virus, leaf spots, honey fungus, aphids, scale insects, and spider mites.

H. quercifolia ‘Snow White’ – Oakleaf hydrangea–

Zones 5-9

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. grandiflora ‘Baby Sun’

Zones 5-9

There are 67-70 species of evergreen or herbaceous, low growing or cushion forming to erect perennial, as well as a few annuals and shrubs that range from a couple inches tall to 5′ feet tall.  They occur mostly in North America (one from Siberia).  They are grown for their showy, fragrant flowers, borne mainly in terminal corymbs or panicle like cymes, sometimes singly.  The flowers are salverform, occasionally funnel shaped, each with a narrow, tubular base opening to 5 flat, ovate petal lobes, sometimes in a star shaped arrangement.  It produces simple, smooth edged, linear to ovate, light to dark green, leaves, often held in opposite pairs, the upper leaves sometimes alternate.  Mat and cushion forming species, from dry, rocky habitats, flower in spring or early summer, grow in a rock garden, in a dry wall, or as edging.  Woodland species are mainly trailing, and usually flower in spring, grow in shady sites.  The taller phlox are mostly from moist riverside habitats, and produce large corymbs of flowers, usually in mid summer into fall, which are good for cutting.  Annuals, from dry rocky slopes and coastal sands, flowers from late spring to autumn, and useful for bedding.

Grow in any moist, fertile, well drained soil, in full sun or light shade.

Prone to powdery mildew, stem canker, rust, southern blight, stem nematodes, Cercospora leaf spots, Septoria leaf spots, leaf miners, caterpillars, red spider mites, eelworm, and dot moth.

P. subulata ‘Candy Striper’ – Moss Phlox –

Zones 3-8

There are 67-70 species of evergreen or herbaceous, low growing or cushion forming to erect perennial, as well as a few annuals and shrubs that range from a couple inches tall to 5′ feet tall.  They occur mostly in North America (one from Siberia).  They are grown for their showy, fragrant flowers, borne mainly in terminal corymbs or panicle like cymes, sometimes singly.  The flowers are salverform, occasionally funnel shaped, each with a narrow, tubular base opening to 5 flat, ovate petal lobes, sometimes in a star shaped arrangement.  It produces simple, smooth edged, linear to ovate, light to dark green, leaves, often held in opposite pairs, the upper leaves sometimes alternate.  Mat and cushion forming species, from dry, rocky habitats, flower in spring or early summer, grow in a rock garden, in a dry wall, or as edging.  Woodland species are mainly trailing, and usually flower in spring, grow in shady sites.  The taller phlox are mostly from moist riverside habitats, and produce large corymbs of flowers, usually in mid summer into fall, which are good for cutting.  Annuals, from dry rocky slopes and coastal sands, flowers from late spring to autumn, and useful for bedding.

Grow in any moist, fertile, well drained soil, in full sun or light shade.

Prone to powdery mildew, stem canker, rust, southern blight, stem nematodes, Cercospora leaf spots, Septoria leaf spots, leaf miners, caterpillars, red spider mites, eelworm, and dot moth.

P. subulata ‘Crimson Beauty’ – Moss Phlox –

Zones 3-8

Cardininal Bush – There are about 12, mostly arching to upright, deciduous shrubs within the Caprifoliaceae family, found naturally occurring in Japan, Korea, and Northeastern China, in this genus.  Most grow 6-10’ feet tall and wide and produce opposite, pointed elliptical, toothed leaves, usually to 4” long.  The foliage often develops orange, red, and purple tone in fall.  Weigelas are grown for their showy, bell to funnel shaped, pink to red, sometimes white or yellow flowers borne in late spring and early summer, these are usually 1 ½” long, and are borne singly or in corymbs or cymes of 3 or 4 on previous years growth, many are sparingly remontant.  Suitable for a mixed or shrub border, or for open woodland garden.  The flowers attract hummingbirds.

Grow in any fertile, well-drained moist soil in full sun or partial shade.

Prone to  root knot nematode, Japanese beetles, scale insects, Verticillium wilt, twig dieback, and lepidoptera.

W. florida ‘Tango’  – Old-fashioned Weigela –

Zones 5-8