SINNINGIA

Named for Wilhelm Sinning (1792-1874), a horticulturalist and botanist at the University of Bonn, this African violet family (Gesneriaceae) genus is made up of about 40 species of tuberous perennials and small shrubs distributed from Mexico to Argentina. The commonly cultivated species are perennials with large lance- to heart-shaped leaves made velvety by a dense covering of fine hairs. The well-known florist's gloxinia (Sinningia speciosa) has large, upward-facing, bell-shaped flowers, although other species have tubular flowers and are sometimes scented. Their vivid showy flowers make the plants ideal for the house or green-house, as well as being lovely summer annuals or year-round plants in subtropical to tropical areas. 


CULTIVATION


They prefer warm humid conditions with a bright but not overly sunny exposure. The soil should be well-drained, moist, and humus-rich. Propagate by lifting and dividing after the foliage has died back, from seed, or by leaf-petiole cuttings. The tubers may be stored dry.


Top Tip


As indoor pot plants, Sinningia species will benefit from half-strength high-potash fertilizer applied every few weeks during the growing season.

SEDUM

This genus of over 300 species of succulent annuals, perennials, and subshrubs is found in the northern temperate regions and the mountains of the tropics. Members of the crassula family (Crassulaceae), species differ greatly in foliage and form. Some are shrubby, with flattened, oval, gray-green leaves, others trail and have succulent, rounded, "jelly bean"leaves, and some form very compact mats. Most produce small heads of tiny, 5-petalled, bright yellow flowers is summer and autumn. The genus name dates from Roman times and was used for several succulent plants. It is derived from the Latin sedo (to sit), referring to their low spreading habit. Some species have been used medicinally and as salad vegetables.


CULTIVATION


Plant in full sun with gritty well-drained soil. Most Sedum species appreciate water at flowering time but are otherwise drought tolerant. Propagate by division, from cuttings, or from seed, depending on the growth type.


Top Tip


The partnership of plump fleshy leaves and dainty starry flowers seen in Sedum species can be used to great effect in the garden to add textural and tonal contrasts.

SCHIZANTHUS

This Chilean genus of  12 species of annuals and biennials is in the potato family (Solanaceae), though that relationship is not obvious. The culivated species are small upright plants with soft green ferny foliage, often with a covering of fine hairs. Their flowers, which appear from spring to autumn, are borne in branching panicles held above the foliage. They are beautifully marked and shaped, with a prominent lower lip, hence the common name of poor man's orchid. Modern strains are available in a wide range of colors and sizes. The genus name comes from the Greek schizo (divide) and anthos (a flower), referring to the deeply divided corolla.


CULTIVATION


Schizanthus plants are tender, but easily grown as annuals where the summer temperatures are warm and even. Elsewhere treat as greenhouse pot plants. Plant in a bright position with fertile, moist, well-drained soil. Raise from seed, with several sowings to ensure containued flowering. Pinch out the growing tips when young to encourage bushiness.


Top Tip


Schizanthus plants are a bit fragile, but are worth the time spent providing care and protection. They don't like heavy rain or temperature extremes.

SCABIOSA

An unpleasant sounding name, Scabiosa is derived from scabies, a Latin word for scurf or manage, the itchiness of which was said to be relieved by running the affected are with the leaves of these plants. The genus, a member of the teasel family (Dipsacaceae), is composed of around 80 species of annuals and perennials found from Europe and North Africa to Japan. Most species form a spreading basal clump of light green to gray-green, rounded to lance-shaped leaves, with deeply incised notches or lobes. A few species have an erect or branching habit. The flowers are individually tiny but occur in rounded to flattened composite heads on stems that hold them clear of the foliage. White, pale yellow, soft pink, blue, and mauve are the usual colors.


CULTIVATION


The plants are hardy and easily grown in any sunny position with moderately fertile, moist, free-daining, slightly alkaline soil. Deadhead to prolong flowering. The annuals are raised from seed, and the perennials can be propagated from seed, from basal cuttings, or by division.


Top Tip


To attract butterflies and bees to the garden, Scabiosa species can be planted in borders and rock garden. The long-flowering species make good container plants.

SAPONARIA

This genus belongs to the carnation family (Caryophyllaceae), and features around 20 species of Eurasian annuals and perennials containing saponin, a glucoside that forms a soapy solution when mixed with water. The roots in particular were once used as soap, and the extract is present in detergents and foaming agents-hence the common name of soapwort. That use aside, these are pretty little plants that are well worth growing for their beauty alone. They are mainly low growing and range from tufted mounds to quite wide-spreading ground covers. They have blue-green linear to spatula-shaped leaves, sometimes toothed, and in summer are smothered in heads of small, starry, 5-petalled flowers.


CULTIVATION


Minly very hardy and easily grown, they do best in gritty, moist, humus-rich, free-draining soil. They will also take slightly alkaline soil. Propagate by cuttings, from layers, or from seed.


Top Tip


Mking a soft carpet of slarry flowers, Saponaria species are most at home spilling over banks, in rockeries, or placed in sunny perennial borders.

SALVIA

Containing about 900 species of annuals, perennials, and softwooded evergreen shrubs, this genus is the largest in the mint family. They are found in temperate and sub-tropical regions throughout the world, with the exception of Australasia, and grow in a wide range of habitats, from coastal to alpine. A number of Salvia species are used for culinary and medicinal purposes, and the genus name is derived from the Latin salvare, meaning to heal or save. Most species are hairy to some extent and many have foliage that is aromatic when crushed or rubbed. The flowers are tubular with the petals split into 2 lips, which may be straight or flaring. The flowers vary greatly in size, and the color range move through shades of blue to purple, and pink to red, as well as white and some yellows.


CULTIVATION


Most are best grown in full sun and all require a well-drained situation; generally, the shrubby plants dislike heavy wet soils. Propagation of most shrubby species is very easy from soft-wood cuttings taken throughout the growing season. Seed of all species is sown in spring.


Top Tip


While many Salvia or sage plants are tolerant of considerable dryness, most benefit from an occassional deep watering.

RUDBECKIA

This North American genus belonging to the daisy family (Asteraceae) consists of 15 species of perennials. It is very popular in gardens because of the plant's great hardiness, ease of cultivation, and valuable late season flowering. Most are fairly bulky plants, with branched or unbranched stems, and often have lance-shaped deeply veined leaves. From late summer they carry masses of large golden yellow daisies, usually with dark brown to black disc florets. Dwarf, double-flowered, and variously colored forms are available. They flower until cut back by frost. Rudbeckia was named by Linnaeus for a professor at the University of Uppsala, Olaus Rudbeck (1650-1740), who employed the young Linnaeus as  a tutor for his children, of which he had 24!


CULTIVATION


Plant in a sunny open position with moist well-drained soil. Deadhead or use as a cut flower to encourage continued blooming. Mildew can occur but usually only late in the season. Propagate by division, from basal cuttings, or from seed.


Top Tip


Because Rudbeckia plants bloom late in summer, they bring welcome color to borders and beds when the blooms of other plants have faded. 

ROSMARINUS

This genus is part of the large mint family, which includes many familar culinary and medicinal herbs. Rosemary itself has been cultivated for centuries, being grown fro the aromatic oil distilled from the shoots and leaves, and for use as a culinary herb. The genus contains just 2 species of evergreen shrubs from the Mediterranean region, and includes up-right and prostrate varities. They have short linear leaves and their small 2-lipped flowers are usually pale blue and borne along the branches, which can become quite woody with age. Apart from its culinary uses, rose-mary has been credited with many properties throughout its long cultivation: in ancient Greece, students wore sprigs of fresh rosemary in their hair believing the invigorating aroma would serve as an aid to mental clarity. This benefit has also been recognized by modern-day pracitioners of aromatherapy.


CULTIVATION


Rosemary likes a hot dry position and will grow in all sorts of well-drained soils; it will not tolerate wet winter conditions. It should be pruned after flowering to maintain a bushy compact habit, and is suitable for use as a hedging plant. Propagation is usually from softwood or half-hardened cuttings taken in summer.


Top Tip


Rosemary is an ideal plant for a mixed border, a hedge, or against a sunny wall. The flowers are edible, as well as decorative, and can be used in salads.

ROSA

The gens Rosa is one of the most widely grown and best loved of all plant genera around the world. Since ancient times roses have been valued for their beauty and fragrance as well as for their medicinal, culinary, and cosmetic properties. There are between 100 and 150 species of rose, which range in habit from erect and arching shrubs to scramblers and climbers. The majority of species are deciduous and most have prickles or bristles. They are found in temperate and subtropical zones of the Northern Hemisphere. The leaves are usually comprised of 5 to 9 serrated-edged leaftlets. Flowers, borne singly or in clusters, range from single, usually 5-petalled blooms to those with many closely packed petals. Many are intensely fragrant. Most species and old garden roses flower only once a year but many of the modern cultivars are repeat blooming. Rose fruits (hips or heps) are usually orangey red, but can be dark, lowa and North Dakota have Rosa arkansana as their floral emblem, while R.laevigata is the state flower of Georgia.


CULTIVATION


Roses can be grown in formal and informal settings, in separate beds, or mixed borders, as ground covers, climbing up arches and pergolas, as hedging, and in containers. Most roses require a sunny site and well-drained medium-loamy soil. Roses should be pruned to maintain strong healthy growth and a good shape. Except for the old Tea roses, most roses are very hardy. Propagation is from hardwood cuttings in autumn or softwood cuttings in summer.


Top Tip


When growing roses in containers, place a layer of stones in the pot, use a soil-based potting mix, and be mindful of the growth habit when selecting the pot.

RHODODENDRON

This very diverse genus of 800 or more species is widely distributed across the Northern Hemisphere, with the majority growing in temperate to cool regions. They range from tiny ground-hugging plants to small trees and even epiphytes, which grow in the branches of trees or on rock faces. Foliage comes in great diversity of form, and most rhododendrons bear "trusses" of up to 24 spectacular blooms, in colors ranging from white to pink, red, yellow, and mauive. Flowers are often multicolored, with spots, stripes, edging, or a single blotch of a different color in the throat of the flower. With the exception of some Vireya species and hybrids, fragrant rhododendrons are always white very pale pink. Blooms vary in sizes and shape but are generally bell-shaped, appearing from early spring to early summer. The fruit is a many-seeded capsule, normally woody wings or taillike appendages to aid transportation. Rhododendron macrophyllum is the state flower of Washington while West Virgina claims Rhododendroa maximum as its state flower.


CULTIVATION


All rhododendrons prefer acidic soils, high organic matter and freely draining. While most prefer some protection from wind, sun, and most many others tolerate these conditions. Evergreen rhododendrons may be propagated by taking up cuttings of the new growth in spring; deciduous azaleas are best grown from hardwood cuttings taken in winter.


Top Tip


Mulching is important for successful rhododendrons. In warm areas, mulch keeps soil cool; in cold areas, mulch helps the soil retain some warmth. 

RANUNCULUS

The type genus for its family, the Ranunculaceae, this is a widespread group encompassing some 400      species of annuals, biennials, and perennials, many of which are cultivated, while others are admired in the wild, and some are despised as invasive weeds. The foliage varies markedly, though glossy, leathery, kidney shaped leaves and deeply lobed leaves predominate. The flowers, too, are often glossy and they are borne singly or in small clusters through spring and summer. Most species have yellow flowers but cultivated forms occur in many colors, such as white, pink, and orange. Raunculus is Latin for little frog, a name given by the Roman Pliny because of the wet conditions in which these plants are often found.

CULTIVATION

Commonly known as buttercups, these plants are very hardy and will grow in a wide range of conditions but they prefer to have their roots kept cool and moist. Many species have trong rhizome that can be invasive if care is not taken to ensure that they are planted where they can be controlled. Propagate by division or from seed. Mildew can be a problem in autumn.

Top Tip

Adaptable to most conditions and soil types, buttercups will bring sunny colors to border or pond edges.

PULSATILLA

This genus of about 30 Eurasian and North American deciduous perennials (family Ranunculaceae) forms clumps of ferny leaves, which in most species are made silver by a dense covering of fine hairs. Long-stemmed cup- or bell-shaped flowers are carried singly with 5 to 8 petals and a prominent golden cluster of stamens. The flowers are graceful and occur in shades of white and yellow to violet-blue. The common name of pasque flower is from the old French word Pasque, meaning Easter, which is around the time when the plants flower in the Northern Hemisphere. Pulsatilla hirsutissima is the state flower of South Dakota.


CULTIVATION


Pulsatilla plants flowers are hardy and need a seasonal temperate climate. They grow well in woodland conditions but are at their best with sun or part-shade and gritty, humus-rich, well-drained by moist soil, such as that found in rocky crevices. Propagate by division when dormant or from seed.


Top Tip


Gardeners with sensitive skin should wear gloves when handling Pulsatilla plants, as both the leaves and the flowers may irritate the skin.

PRUNUS

Commonly known as cherry or cherry plum, Prunus includes both ornamental and fruiting species-cherries, plums, apricots, peaches, and nectarines-that are naturally widespread throughout the northern temperate regions and also have a toehold in South America. The genus also includes a wide range of shrubs and trees, many of them deciduous. Most bloom from late winter to early summer, producing flowers either singly or in clusters, in colors from white through to dark pink, followed by fleshy single-seeded fruit. The leaves are usually simple pointed ellipses, often with serrated edges, which sometimes develop brilliant autumn colors. Prunus persica is the state flower of Delaware.


CULTIVATION


Plant in moist, fertile, humus-rich, and well-drained soil in full sun. Provide some protection from strong wind. Propagate the fruiting plants by grafting, and the ornamental plants by grafts or in some cases by cuttings.


Top Tip


Correct pruning techniques are vital for fruiting varieties of Prunus, but less so for ornamentals, if silverleaf disease is present, cut back in summer rather than in winter.

PRIMULA

This well-known genus of perennials is native to the Northern Hemisphere. The heavily veined, toothed, or scalloped-edged leaves are pale to dark green and form basal rosettes. Single blooms may be tucked in among the leaves or borne in clusters throughout spring. The tubular flowers open out into a funnel shape or flat disc; are made upt of 5 or more petals, which are notched at their tips; and come in a variety of colors ranging from white, yellow, and pink to lilac and purple. Primulas are known variously as primrose, polyanthus, and cowslip, and some have been used medicinally for their astringent and mildly sedative properties.


CULTIVATION


Most species prefer the dappled shade of a woodland garden and like moit, humus-rich, well-drained soil. The so-called bog primroses prefer damper conditions and often naturalize along streamsides. Propagate from seed or by dividing established clumps when dormant.


Top Tip


Primulas can bring a burst of life to the garden. Easy to grow and readily available, they come in a wide array of different colors. 

POTENTILLA

This is a large genus of some 500 species belonging to the rose family. While most are herbaceous perennials, the shrubby species can be extremely useful as small ornamental plants. They are indigenous to the Northern Hemisphere, occurring from temperate to arctic regions. The gray-green to dark green leaves are mostly made up of 5 small leaflets and can have the appearance of feathers. The pretty flowers resemble small single roses; they appear from spring to summer and sometimes autumn, in small colorful clusters of yellow, orange, pink, and blood red Some species are used medicinally-the root bark of Potentilla reptans is said to stop nosebleeds and even internal bleeding.


CULTIVATION


These are hardy plants that grow in full sun or part-shade, preferring a fertile well-drained soil. Cultivars with orange, red, or pink flowers need to be carefully placed where they will receive some shade during the hottest part of the day. Propagation is from cuttings in summer or seed in autumn.


Top Tip


To make room for new growth, the oldest stems of Potentilla plants should be cut out every few years. This should be done only when flowering is over.

PLEIONE

This is a small genus of about mostly semi-alpine minitature orchids that are related to Coelogyne. The species occur at high altitudes in a wide variety of mountainous habitats from Nepal to China. They mostly grow in the ground or on mossy limbs of trees or fallen rotting logs. One or two deciduous oval-shaped leaves grow from a bulblike stem, known as a pseudobulb. The large and showy flowers are borne on short stems, appearing mostly in spring, through they can appear at vaious times of the year. The white, cream, purple and pale pink flowers are intriguingly shaped with an unusual frilled lower lip surrounded by 5 straplike petals.


CULTIVATION


These plants are easy to grow in mild cool climates with protection from the winter wet. They are usually grown in pots in rich well-drained orchid potting mix and like part-shade. Propagate by division.


Top Tip


Pleione plants are relatively easy to grow and so are ideal for beginners or children. They can be kept in a greenhouse or on a cool windiosill.

PLATYCODON

The sole species in this bellflower genus (Campanulaceae) is a perennial found in Japan and nearby parts of China. also known as the Chinese bellflower, it is a fast-growing clump-forming plant with bold, lance-shaped, blue-green leaves with toothed edges. The flowers open from enlarged ballon-like buds, giving the plant the common name of balloon flower. Once opened, the flowers are cup-to bell-shaped, with 5 broad lobes; they are white, pink, or blue and, depending on the cultivar, come in double-flowered and dwarf forms. Playcodon root has long been used in traditional Chinese medicine and is now being studied for its gene mutating effects on tumors. 


CULTIVATION


This perennial is best in distinctly seasonal temperate climates. Plant in sun or part-shade with moist, humus-rich, well-drained soil. While it may be slow to become established, it is long-lived and very hardy. Propagate from seed or by occasional division.


Top Tip


The hardy versatile play codon plant is a good specimen for herbaceous borders or rock gardens. It also works as a cut flower.

PIERIS

This Erica family genus consists of  7 species, mainly evergreen shrubs from the subtropical and temperate regions of the Himalayas and eastern Asia, as well as a vine and some shrubby species from eastern  America and the West Indies. The species have been widely cultivated and extensively hybridized, and the best known are extremely popular evergreen shrubs for temperate gardens. typically, the glossy green leaves are simple, pointed, and elliptical-shaped, often with serrated edges, and the flowers are bell-shaped, downward-facing, and are borne in panicles of white to pale pink clusters. The flowers usually open in spring and are sometimes scented.

CULTIVATION


Pieris plants will perfrom best in cool, moist, humus-rich, well-drained soil. A position in full sun yields more flowers, wheres light shade produces foliage that is more lush. They are naturally tidy plants, but a light trimming will help keep them that way. Propagate from half-hardened cuttings or by layering.

Tip Top


Pieris species make good companion plants for heath (Erica species), azaleas, and rhododendrons as they all enjoy an acid soil and warm, but not hot, summers.

PHYSOSTEGIA

This North American genus is a member of the mint family (Lamiaceae), and is made up of 2 species of perennials. Most form a clump of unbrached upright stems covered with dark green, toothed, narrow eliptical to lance-shaped leaves. From late summer to early autumn, flowerheads develop at the stem tips and are made up of clusters of 5-lobed, tubular to bell-shaped blooms, mainly in pink and purple shades. Though sometimes called false dragonhead, Physoslegia species are more commonly known as the obedient plant, a refeence to the way in which the flowers remain in place when twisted or moved.


CULTIVATION


These easy-growing hardy plants do best in any full or half sun position with moist well-drained soil. They spread by their fleshy roots and can become invasive. Propagate by division.


Top Tip


Physostegia plants make excellent choices for the back of borders, as they offer height and color with their tall flowering spikes, and coverage with the foliage clumps.

PHLOX

This genus contains 67 species of annuals and perennials and belongs to the phlox family, the Polemoniacea. Annual phlox tend to be small mounding bushed; rock phlox closely hug the ground; trailing forms have long stems; and border phlox are upright and bushy. The leaves range from rounded and shiny to narrow and hairy, depending on the species. The small flowers are long-tubed, widely flared, bell-shaped, slightly fragrant, and grow in clusters of brightly colored floral sprays ranging from white and pale pink to bright pink, red, and purple. The genus name Phlox comes from the Greek word for flame. Use in bedding and border schemes.


CULTIVATION


Although all species prefer well-drained soil that can be kept moist, annual and rock phlox need full sun, while border and trailing forms will grow in part-shade. Border phlox need good ventilation to prevent mildew. Propagate from seed, by division, or from cuttings.


Top Tip


Clumps of summer phlox should be divided every 3 to 4 years. Divide carefully using a clean sharp knife, making sure that each division has a good set of roots.