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

grow in full sun to partial sun

blooms late summer

P. fruticosa – Ming Aralia – This large shrub or small tree probably originating in Northern Australia and Western Pacific region and grows to 25′ feet tall. It produces finely cut, bright green often red tinted, pinnate to tripinnate leaves up to 30″ long. The individual white to cream flowers are tiny, but are borne in panicles to 24″ long. It is a very graceful plant best trained to a canopy with either single or multiple trunks. Use as a interior specimen.

Indoors, grow in soil based potting mix in full light or bright filtered light. In growth, water freely, mist daily, and apply a balanced liquid fertilizer every month.

Zones 12-14

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. carolina ‘Miss Lingard’ – Carolina Phlox – Thick-leaf Phlox –

zones 5-8

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 ‘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

perennial

L. punctat – Whorles loosestrife – Golden Loosestrife – Garden Loosestrife – This vigorous, erect, rhizomatous, softly hairy herbaceous perennial found from Central and Southern Europe to Turkey grows 3′ feet tall and 2′ feet wide. It produces opposite or whorled, elliptic to lance shaped, mid green leaves, to 3″ long. In mid and late summer it bears whorls of starry shaped yellow flowers, to 1″ across. May become invasive.

Grow in humus rich, preferably moist but well drained soil that does not dry out in summer, in full sun or partial shade. Tall species may need support. Divide in spring or autumn.

Zones 4-8