Thursday, October 27, 2011

ZANTEDESCHIA

The large calla lily (Zantedeschia aethiopica) is a plant that polarizes opinions. Some gardeners love it, while others can't abide its funereal associations. Named for Italian botanist Giovanni Zantedeschi (1773-1846), this arum family (Araceae) genus comprises 6 species of rhizome-rooted perennials from southern Africa. They have large, elongated, upward-facing, heart-shaped leaves that taper to long drip-tips and are sometimes speckled with translucent spots. The flower spathe is funnel-shaped and also tapers to a drip-tip. The spikelike spadix may be enclosed within the spathe or protrude slightly. Although the white calla is the best known, modern hybrids cover a wide color range. Both the leaves and the flowers are supported by strong stalks.


CULTIVATION


Cultivated Zantedeschia species may withstand moderate frosts. They lose their leaves in cold winters but may retain some in milder conditions. Some prefer damp, almost boggy conditions but most will grow in full or half sun in any garden soil that does not dry out. Propagate by division, or from basal offsets or seed.


Top Tip


These wonderful house plants will perform well if placed near a window and given some protection against the midday sun. They are also superb in cut-flower arrangements.

YUCCA

Native to hot dry regions stretching from North to Central America and the West Indies, there are about 40 species in this genus within the Agavaceae family, including evergreen herbaceous perennials, trees, and shrubs. They have a strong bold form with strap-to lance-shaped leaves arranged in rosettes. Bell-to cup-shaped flowers are held on mostly erect panicles. Flowers are usually white or cream, though they may be tinged with purple. Yucca whipplei holds the record for the fastest plant growth; its flowering spike emerges and grows to 12 ft (3.5 m) in just 14 days. Yucca glauca is the state flower of New Mexico.


CULTIVATION


Yucca species grow best in loamy soil with good drainage, but will tolerate poor sandy soil. They range from frost hardy to frost tender. In colder areas it is advisable to grow the tender species in large pots in loam-based potting compost and overwinter indoors. If grown outdoors they need good light in summer, a monthly feed, and careful watering. Propagation is by sowing seed in spring, although seed may take some time to germinate. Take root cuttings in winter, or remove suckers in spring.


Top Tip


With their dramatic foliage and form, these are not plants for crowded corners. As in their native environment-deserts and sand dunes-a sparse setting suits them best.

WISTERIA

Often seen luxuriously covering porches and verandahs and capable of spreading a considerable +distance, the 10species of twining deciduous vines of the genus Wisteria belong in the pea family (Fabaceae). When young, the pinnate leaves are a soft bronze-green shade but turn light green when mature. The flowers, primarily mauve in the species, occur in long racemes and start to open as the leaves expand. Cultivated forms occur in white and a range of pink to purple tones. The Gnglish botanist Thomas Nuttall named the genus for Caspar Wistar (1761-1818), a professor of anatomy at the University of Pennsylvania, though the reason for the change in spelling of his last name remains unclear.


CULTIVATION


Like Clematis, wisterias prefer to have their tops in the sun and their roots in cool, moist, humus-rich, well drained soil. They are hardy, heavy-wooded, vigorous climbers that need sturdy support and routine trimming. Propagate from cuttings, layers, grafts, or seed.


Top Tip


Wisterias can be trained against walls, up trees, and over arbors. They can also be treated as free-standing plants-just as long as they have strong support.

WEIGELA

The10 or 12 species of this genus within the Caprifoliaceae family are deciduous long_lived shrubs with opposite oblong to elliptic leaves. Their natural habitat is scrubland and the edges of woods in eastern Asia. Cultivated for thier bell- or funnel-shaped flowers that are produced in late spring and early summer, they have pink, red, white, or sometimes yellow blooms, which growon  the previous year` wood.The leaves make a subtle background to the colorful flowers; mostly dark green, some hybrids have yellow-green, golden yellow or variegated leaves.

CULTIVATED


Weigela shrubs need moist but well-drained fertile soil in sun or partial shade. Propagate by sowing seed in autumn in an area protected from winter frosts or from half-hardened cuttings in summer. Seed may not come true, as they hybridize freely.

TOP TIP


These neat shrubs make excellent border plants and ornamentals. There are a great many hybrieds, offering a choice of plant size and flower color.

Tuesday, October 25, 2011

VIOLA

The type genus for the family Violaceae, Viola includes some 500 species of annuals, perennials, and subshrubs found in the world's temperate zones, ranging from the subarctic to the mountains of New Zealand. The majority are small clump-forming plants with lobed, kidney-shaped, or heart-shaped leaves. All violas have similarly shaped 5-petalled flowers, with the lower petal often carrying dark markings. White, yellow, and purple predominate but the flowers occur in every color, at least among the garden forms-often referred to as violets or pansies. The genus was named for a lover of the god Zeus, and Viola tricolor was used as a symbol of Athens. V. palmata is the floral emblem of Rhode Island, while both New Jersey and Wisconsin have adopted V.Soroia as their state flower.


CULTIVATION


These plants are mostly very hardy and easily grown in sun or shade. The woodland species prefer humus-rich soil, while the rockery types require something grittier, but most are fine in any moist well-drained soil. Propagate by division, or from seed or basal cuttings.


Top Tip


Plant garden pansies, vviolas, and violettas in window boxes, containers, and borders, or beneath taller shrubs for  splash of bold color.

VIBURNUM

This genus consists of 150 easily grown; cool-climate; deciduous, semi-evergreen, or evergreen; shrubby plants that are grown for their flowers, autumnal leaf color, and berries. Most have erect branching stems, paired leaves, and a spread about two-thirds their height. Small, sometimes fragrant, white flowers are displayed in dense clusters. In certain species the flowers somewhat resemble lacecap hydrangeas; like them, they bear sterile ray florets that surround a center of small fertile flowers. The buds and petals, particularly in cultivars, may be softly colored in tints of pink, yellow, and green. The berries are vividly colored, often red, blue, or black.


CULTIVATION


Light open positions and light well-drained soils are preferred. Many are drought tender. Prune the evergreens by clipping in late spring and the deciduous species by removing entire old stems after flowering. For a good berry display, grow several shrubs in the same area. Propagation is from cuttings taken in summer, or from seed in autumn.


Top Tip


Bring interest to the winter garden with late-flowering species such as Viburnum tinus, and with species such as V.opulus, whose leaves turn red in autumn.

VEROICA

A figwort family (Scrophulariaceae) genus of 250 species of annuals and perennials, it is widespread in the northern temperate zones. Most species are creeping mat-forming plants that sometimes strike root as they spread. Their leaves tend to be small, oval to lance-shaped, often shallowly toothed, and rarely pinnately lobed. A few species have solitary flowers but more often upright spikes bearing many flowers develop in spring and summer. The color range is mainly in the white and pink to rich purple-blue shades, including some striking deep blue flowers. The genus is probably named in honor of St.Veronica, perhaps because the floral markings of some species are said to resemble the marks left on Veronica's sacred veil, with which she wiped Christ's face as he carried the cross.


CULTIVATION


Mostly hardy and easily grown in full or half sun with moist well-drained soil, some are great rockery plants, while others are suited to borders. Propagate from cuttings, self-rooted layers, division, or seed.


Top Tip


These mostly hardy plants are not fussy, managing in any reasonable soil. Protect plants with downy leaves from winter wet.

VERBASCUM

This figwort family (Scrophulariaceae) genus of some 300 species of annuals, biennials, perennials, and subshrubs includes cultivated plants and many that have become weeds outside thier natural Eurasian and North African range. The commonly cultivated species usually form basal rosettes of large elliptical leaves, often quite heavily veined and sometimes felted .Tall upright flower spikesemerge from the rosettes carrying massed, small 5-petalled flower,usually in wight ,yellow,or pink to lavender shades.The Roman pliny described verbascum ,noting that they attracted moths and thus called them moth mulleins, and in Greek legends the plant featured as a protection against evil and was used as an everyday medicinal plant to treat a variety of illness.

CULTIVATION

Hardiness varies with the species .Most prefer a sunny position in light , gritty, free-draining soil .They can toleratesummer drought but need moisture until flowering has ended . Propagate by divion or from seed      ,depending on the growth form .

Top Tip

You can encourage the production of fresh flowering spikes by cutting off  the spikes  with spent flower just below the bottom-most flower.                                                                                                                                                                                      

VANDA

This is a group of about 50 species of sturdy single-stemmed orchids with representatives from Sri Lanka and India, across Southeast Asia to New Guinea and northeastern Australia. They are erect growing, with straplike semi-rigid leaves in 2 ranks. Larger plants may branch at the base, and have numerous, very thick, cordlike roots. The flowers appear from the stem at the base of the leaf. They have showy long-lasting blooms, which come in a range of colors, often with delicate markings. This is one of the most important genera of plants for cut-flower production in Thailand and Singapore. A large export industry has developed using a handful of species in an extensive hybridizing program, both within Vanda and in combination with related genera.


CULTIVATION


Vanda plants are easy to grow in wooden baskets, with most thriving in bright, humid, and warm to intermediate conditions. During the warmer months they require liberal watering; reduce this over winter. Plants are mostly frost tender.


Top Tip


Vanda plants need a coarse growing medium, so add charcoal or bark chips to the potting mix. Humidity is also important-regularly spray the leaves with a fine mist of water.

TULIPA

Occurring naturally in the northern temperate regions, especially central Asia, the genus Tulipa contains around 100 species of bulbs. They have been cultivated for at least 3,000 years and reached Europe from Turkey in 1554. They quickly became a garden favorite but it was not until the Dutch "tulipomania" of the 1630s that tulips became established in our folklore as well as our gardens. Tulip leaves are gray-green to blue-green and may be grassy or quite broad, with contrasting markings. The flowers vary widely between the species, and so many hybrids and cultivars exist that they are often divided into 15 groups based primarily on parentage and flower type. The blooms are unfailingly delightful, especially if planted as a massed bedding of a single type.


CULTIVATION


Tulips need a temperate climate and winter chilling. They do best in a sunny position that does not bake in summer. Plant fairly deeply in autumn, around 6 in (15 cm) deep, and water well once the foliage appears. Propagate hybrids and cultivars from offsets; the species can be propagated from seed.


Top Tip


When cutting tulips for indoor decoration, select flowers that have not yet opened and cut them early in the morning while the day is still cool.

TROPAEOLUM

Found from Mexico to the southern tip of South America, this genus contains about 80 species of annuals and perennials commonly known as nasturtiums. Many are climbers, using their twining leaf-stalks to scramble and cling. Though variable, the foliage is often shield-shaped and tinted blue-green. All species have long-spurred 5-petalled flowers which occur in a wide range of mainly warm shades. The degree of development of petals and spurs varies, leading to a range of flower shapes and sizes. The genus name comes from the Greek tropaion (trophy), a term used for the trtee trunks on which were hung the shields and helmets of defeated enemies. Tropaeolum leaves (shields) and flowers (helmets) reminded Linnaeus of this Greek tradition, and he named the genus accordingly.


CULTIVATION


Plant in full or half sun with moist well-drained soil. Plants may need trimming back and support for climbing stems. Propagate by division, from basal cuttings, or from seed.


Top Tip


Tropaeolum seeds should not be sown until after the last frosts. Feeding is often not required and some species, such as Tropaeolum majus, actually prefer poor soil.

TRILLIUM

This striking group of 30 rhizome-rooted, spring-flowering, woodland perennials from North America and temperate Asia is the type genus for its family, the Trilliaceae. The genus name is derived from tri-lilium, 3-part lily, because the leaf and floral parts are grouped in 3s. Although ranging from the tiny Trillium rivale at just a couple of inches high through to species that are 24 in (60 cm) tall in flower, the genus is remarkably consistent in form. The leaflets are bright green, often silver- or purple-mottled, and usually broadly oval, tapering to a point. At the center of the 3-leaf cluster is a simple 3-petalled flower that may be white, cream, pink, or deep maroon.


CULTIVATION


Plant Trillium species in part- or full shade in cool, moist, humus-rich, well-drained soil. All species die away completely in autumn but quickly return to growth in early spring, often flowering before the equinox. The common name of wake robin comes from this early flowering habit-it is supposedly the plant that wakes the robin in spring. Propagate by division of the rhizomes after flowering, or from seed. 


Top Tip


Trillium species are best planted under trees and large shrubs where the conditions match their native habitat. Once established, they require very little attention.

TRIFOLIUM

Trifolium, or clover, is so well-known that the leaf shape is not just a description in itself, but a symbol, too. Associated with Ireland ever since St.Patrick used it to describe the Christian Trinity, the cloverleaf and the 4-leafed shamrock are today primarily associated with good luck and have been adopted by countries, footfall teams, and casinos. Clover is also a vitally important component in the world`s pastures while at the same time being far less welcome in its lawns. Found naturally throughout the temperate and subtropical zones expect Australasia, Trifolium is a genus of around 230 species of annuals, biennials, and perennials of the pea family (Fabaceae). Leaves are typically trifoliate and bright green, and are sometimes darkly marked. Examined closely, the individual flowers are very much like pea-flowers. They are borne in rounded heads or terminal racemes. Trifolium pratense is the state flower of Vermont.


CULTIVATION


Trifolium species are usually hardy and easily grown. Plant in full or half sun with moist well-drained soil. The plants may be divided, but they usually self-sow.


Top Tip


When growing clover in pots, use a potting mix that contains equal proportions of loam, sand, and leafmold. While growing, keep moist during the winter months.

TRADESCANTIA

Introduced to cultivation in 1637 by John Tradescant the Younger and named for him by Linnaeus, this dayflower family (Commelinaceae) genus of around 70 species of annuals and perennials from the Americas includes a few that, while attractive as garden plants, have become serious pests in some areas. Tuberous or fibrous rooted and often evergreen, they have rather succulent stems and fleshy, pointed elliptical, lance-shaped, or narrow leaves. Attractive variegated and colored foliage forms are common. Clusters of small 3-petalled flowers subtended by bracts appear over the warmer months and are sometimes very bright magenta, though white, soft pink, and blue to mauve color predominate.


CULTIVATION


Most species are tolerant of light to moderate frosts. Some prefer a sunny aspect and are drought tolerant, but most are happier with part-shade and moist well-drained soil. Propagate by division, from tip cuttings, or from seed, depending on the growth form.


Top Tip


Very hardy in mild climates, Tradescantia, or spiderwort, plants may need to be grown in a greenhouse in cooler areas. A general fertilizer can be of benefit in early spring.

THUNBERGIA

This Old World tropical genus consists of around 100 species of annuals, perennials, and shrubs of the acanthus family. Many are vigorous twining climbers, while others are shrubby in habit. They are an enormously varied group, usually with pointed oval to heart-shaped leaves, sometimes lobed or toothed. The flowers occur in a wide color range: mostly yellow, orange, and purple-blue shades. They may be borne singly or in racemes and are mostly long-tubed trumpets with 5 large lobes. The genus was named for Carl Peter Thunberg (1743-1828), a Swedish physician and botanist employed by the Dutch East India Company. He was the first Western botanist to visit Japan in over 100 years, and brought back to Europe flora that was previously largely  unknown.


CULTIVATION


Thunbergia species are frost tender or tolerant of very light frosts. Plant in a warm sheltered position with moist, humus-rich, well-drained soil. Many species are drought tolerant; most perform best with frequent watering and feeding. Propagate from cuttings or seed.


Top Tip


For an eye-catching effect in the garden, train Thunbergia specie up though other annuals, such as sunflowers, or around and through the branches of a small tree.

THALICTRUM

A buttercup family (Ranunculaceae) genus of around 130 species of tuberous or rhizome-rooted perennials, Thalictrum is found mainly in the northern temperate zone, with a few species straying south of the equator into the tropics. They are upright plants with lacy, pinnate, blue-green leaves reminiscent of aquilegia or maidenhair fern foliage. Tall elegant flower stems grow well above the foliage, and from late spring to autumn, depending on the species, the stems bear clusters of small fluffy flowers. Occurring mainly in pink and mauve, but also in white and yellow, the petalless flowers may sometimes gain color from the 4 to 5 petallike sepals. Also known as meadow rue, Thalictrum plants were significant in the herbal lore and medicine of ancient Rome.


CULTIVATION


These plants are mostly hardy and easily grown in a temperate climate in full or half sun. The soil should be fertile, humus-rich, and well-drained. It is usually propagated by division, as cultivated plants are mainly selected forms.


Top Tip


Thalictrum species are useful plants in woodland gardens, borders, or rock gardens. The ferny foliage is an effective backdrop in floral arrangements.

Monday, October 24, 2011

TAGETES

Although the commonly grown marigolds are often knowns as African or french, in fact, all but one of the
50-odd species of this daisy family (Asteraceae) genus originate in the American tropics and perennials with darkgreen ,sometimes aromatic , pinnate  leaves that have toothed edges. Their flowers, usually a vibrant golden yellow or orange, are often typically daisylike, with obvious ray and disc florets, but in some forms the disc florets are largely hidden. The genus name comes from Tages, an Etruscan deity, grandson of Jupiter, who sprange from the ploughed earth. This is a reference to the marigold's habit of just poping up from seed.


CULTIVATION


Tagetes plants prefer a warm sunny position with light well-drained soil. Water well and feed if the foliage is at all yellow. Deadhead frequently to ensure continuous blooming. Propagate from seed, which is usually started indoors in early spring.


Top Tip


African marigolds, such as Tagetes, Antigua Series, are excellent for cutting because the dense pomponlike flowerheads last for a long time in fresh water.

SYRINGA

Pity the tropical gardener who has never breathed the scent of lilacs in the spring. This olive family (Oleaceae) genus is made up of only around 20 species but was so greatly developed by Lemoine and later hybridizers that the selection is now huge. Syringa,or lilac, species are mainly deciduous shrubs and trees, and naturally occur from southeastern Europe to Japan. They have simple, pointed, elliptical or heart-shaped leaves and in spring produce upright panicles of small 4-petalled flowers with an overpowering fragrance. Flowers may be white or shades of pink, red, purple, and blue. The genus name comes from the Greek syrinx (a pipe), which refers to the hollow stems, and is also the origin of the word syringe.


CULTIVATION


Mostly hardy, Syringa plants prefer full or half sun and fertile, moist, humus-rich, well-drained soil. The roots can be invasive, and continually removing suckers can weary even the most ardent lilac lover. Propagate species by seed or cuttings, and cultivars by cuttings or grafting.


Top Tip


Because most lilacs bloom on the previous year's wood, pruning should be done immediately after the flowers have finished. To encourage new growth, the old stems should be cut out each year.

STREPTOCARPUS

Although widespread in the African and Asian tropics and subtropics, most of the cultivated plants in this African violet family (Gesneriaceae) genus of around 130 species of annuals and perennials are natives of southern Africa. They are a very diverse group, ranging from tiny rosette-forming plants to others that produce just a single huge leaf. But despite this variation of form they share some features, especially among their flowers. The leaves are velvety, heavily veined, and slightly crinkled. The flowers are long-tubed, primroselike, and usually have 5 petals; they occur in heads on short upright stems. The genus name is of Greek origin, derived from streptos (twisted) and karpos (a fruit), referring to the unusual form of the spirally twisted fruits.


CULTIVATION


Cold tolerance varies, though none withstand more than the lightest frost. Plant in a bright but not sunny position that is warm and draft-free. The soil should be fertile, moist, humus-rich, and well-drained. Propagate by division, from leaf-petiole cuttings, or from seed.


Top Tip


Treat Streptocarpus plants similarly to Saintpaulia when grown indoors. Use an African violet potting mix and place in a bright but not too sunny spot.

STOKESIA

Although there is just 1 species in this daisy family (Asteraceae) genus, it has been extensively developed in cultivation and is now available in a wide range of plant sizes, flower colors, and forms. A summer- to autumn-flowering perennial from the south-eastern U.S.A., Stokesia-or Stokes' aster-was named for Dr.Jonathan Stokes (1755-1831), English doctor and botanist. It arrived in England in 1766 and was in vogue in Victorian times, especially as a cut flower. It later languished but is now popular again. Stokesia is an upright plant with simple ever-green leaves borne in basal rosettes and large cornflowerlike heads of white, yellow, or mauve to deep purple-blue flowers. Stokesia plants are well suited to herbaceous borders.


CULTIVATION


Plant in full or half sun in light free-draining soil. Water and feed well. Watch for mildew in late summer. Propagate by division near the end of the dormant period, or raise from seed.


Top Tip


To prolong the Stokesia flowering season, remove the spent flower stems immediately. This cornflower look-alike is ideal for cutting and drying.

SPIRAEA

This genus consists of about 70 species of mainly deciduous, but sometimes semi-evergreen, flowering shrubs from the rose family (Rosaceae). They are found in many northern temperate areas, mainly in eastern and southeastern Asia, as well as in North America. Plants are highly appreciated for their flowering and foliage qualities. Leaves are simple and alternate, variously toothed and lobed, and may have gray or blue-gray downy undersides. Many species have attractive golden, orange, or bronze foliage over autumn. Flowers are borne in dense profusions in clusters, on terminal panicles, or along branch tips in spring or summer. The color range is generally white, yellow, pink, or crimson. The genus Spiraea is commonly known as bridal wreath.


CULTIVATION


They thrive in most soils, though some grow poorly on chalk, and prefer a sunny position and cool moist conditions. For prunning purposes, these plants fall into 2 groups: those that flower on the current year's growth, which can be hard pruned in spring, and those that flower on the previous year's growth, which should have old flowering shoots removed just after flowering. Propagation is from soft-tip or half-hardened cuttings in summer.


Top Tip


A second bloom will occur if spent flower clusters are removed after the first flowering. However, the second bloom will be less profuse.

SPARAXIS

A South African genus of 6 species of corms of the iris family (Iridaceae), Sparaxis plants will naturalize and form large drifts of brightly colored flowers under suitable conditions. The leaves are grassy to sword-shaped, with prominent ribbing, and develop quickly from late winter. They are soon flowed by wiry spikes carrying anywhere from just a few blooms to fanlike sprys of funnel-shaped 6-petalled flowers. The flowers may be white, yellow, or shades of pink to orange and red, usually with a yellow center and contrasting dark colors in the throat. The genus name comes from the Greek word sparasso (to tear), referring to the lacerated bracts at the base of the flowers.


CULTIVATION


These plants are not hardy where the soil freezes but are otherwise easily grown in full sun with fertile, moist, well-drained soil. In cold areas they can be lifted in autumn and replanted in early spring for a later flower show. Propagate from seed or by division.


Top Tip


Sparaxis species are suitable for the front of borders or in raised beds. In cold areas they may need to be placed in a greenhouse, or planted against a sunny wall, protected from wind.

SOLIDAGO

Although a few species are dotted in other temperate regions, this daisy family (Asteraceae) genus of around 100 specie of perennials is primarily North American. They form clumps of upright, sometimes branching stems, the upper half of which bear panicles of tiny golden yellow flowers; these have earned the plant the common name of goldenrod. The leaves may be lance-shaped, linear, or a pointed oval shape, and often have toothed edges. By the time flowering starts in late summer many of the lower leaves have withered somewhat. Native Americans used this lateflowering habit as a guide to when the corn would ripen. Solidago altissima is the state flower of Kentucky, and S.gigantea is the state flower of Nebraska.


CULTIVATION


Solidago plants are hardy and easily grown in full or half sun in any position with reasonably fertile, moit, well-drained soil. They will grow in poor soil and withstand drought but will not flower well or reach their maximum size with such conditions. Propagate by division, or from seed or basal cuttings. They may self-sow.


Top Tip


When selecting a Solidago plant for the garden, the named cultivars are preferable to the species because they are sturdier and less invasive.

SOLANUM

Famous for the humble potato (Solanum tuberosum) in its myriad forms, this genus includes some 1,400 species of often tuberous-rooted herbs, vines, shrubs, and trees that have a cosmopolitan distribution, with many from tropical America. The trees and shrubs may be evegreen or deciduous and many are armed with thorns. They are a variable lot but their flowers are all remarkably similar, being simple, small, 5-petalled structures carried singly or in clusters with a central cone of yellow stamens. Fleshy berries follow the flowers and are often the most brightly colored part of the plant. Some species have spherical fruit, while others have elongated fruit shaped like chilies. The berries are usually somewhat poisonous and, because of their conspicuous color, may be attractive to children.


CULTIVATION


These plants vary in hardiness, though few are really frost tolerant and most are quite tender. They are generally easily grown in any well-aerated well-drained soil. Most species prefer sun or partial shade. Propagate from seed or cuttings, or in a few cases by division.


Top Tip


The climing Solanum species can be trained to grow over atall trees, pergolas, and eaves, or against a sunny wall.

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.

Sunday, October 23, 2011

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.

Wednesday, October 19, 2011

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.

Tuesday, October 18, 2011

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.

Monday, October 17, 2011

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.

Thursday, October 13, 2011

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.