Posts Tagged ‘Perennials’

Perennials – Rudbeckia Fulgida (Orange Coneflower)

Tuesday, July 21st, 2009

Rudbeckia fulgida has several common names; Black-eyed Susan, Orange Coneflower, Brilliant Coneflower and Eastern Coneflower. It bears large, yellow, daisy-like flowers with a black-brown centre cone from August through to October and they can grow up to 5in (12cm) across. During late spring and summer, its dark green foliage provides an effective backdrop for earlier flowering plants.
orange coneflower
This is a plant that is naturally at home in moist, though well-drained meadows. The flowers will last longer if the soil retains moisture, so add some organic matter to soils that have a tendency to dry out in the summer. For the best production of flowers, grow in a sunny position, although light shade will be tolerated.

The orange coneflower is fully hardy, but prefers a sheltered spot in gardens exposed to the wind, where a shorter variety could be grown or the plants staked. A lightweight mulch of heather or bracken can be used in periods of prolonged cold over the winter.

The flowers are long lasting when cut. After flowering, remove the dead heads, unless you are going to collect the seed. Plants should be divided every four to five years. Rudbeckia fulgida can become invasive when grown in good soil, so root pruning in spring is recommended to keep it in check.

Growing Requirements

Soil
Rudbeckia fulgida will thrive in any type of soil but well-rotted organic matter should be added to the site before planting.

Size
Plants will grow to around 3ft (1m) high and spread about 2ft (60cm) depending on which cultivar is chosen.
Propagation
The plants may be propagated by division in spring. but can also be grown from seed. Sow the seed into a prepared seedbed during March/April. An early sowing should produce flowers in the first year.

Family: Asteraceae
Genus: Rudbeckia


Grasses – Blue Fescue (Festuca Glauca)

Wednesday, June 10th, 2009

Festuca Glauca is a fabulous dwarf grass, and very popular in modern garden design, that exhibits one of the best blues of all grasses and grows in dense, rounded tussocks. It has stiff, ribbon-like leaves with flower spikes that appear in summer.
blue fescue
Blue fescue can be grown for foliage interest in amongst rock garden plants, as a container plant or as ground cover in the front of a well-drained border. If several plants are put close together they can be mown and used as a lawn. The plants will complement a wide variety of colours, but looks especially good with purple-leaved plants.

Like most grasses, Festuca glauca prefers full sun. If grown in the shade, it will lose its lovely blue colour and revert to green. This plant should need no watering, except when first planting out, as it can tolerate lengthy dry spells. Blue fescue should be planted out in the spring. Groups of plants should be set about 9in (23cm) apart.

This is a hardy plant and needs no protection during the winter. It is not so happy under wetter conditions and could well die out if not divided regularly or given a free draining or drier situation.

Cut back the foliage in early spring to 4in (10cm) to tidy up the plants and to encourage new leaf growth, which will be the bluest. The clumps have a tendency to die out in the centre and will need to be divided and replanted or replaced every two to three years.

Growing Requirements

Soil
Festuca glauca will grow in most types of soil, but it does best on light, sandier ones. It has a tendency to be short-lived when grown on heavier soils.

Size
Blue fescue will grow to around 10in (25cm) high and spread about 8in (20cm).

Propagation
The easiest method of propagation is by dividing well-established clumps in spring, but plants may also be grown from seed.

Family: Poaceae
Genus: Festuca


Perennials – Chinese Lantern (Physalis Alkekengi)

Friday, April 10th, 2009

This European plant has a long history of garden use, first appearing in texts of the sixth century. Its other common names are bladder cherry, Japanese lantern and winter cherry. It is often grown for its autumn fruits, which are much used by flower arrangers.
chinese lantern
Physalis alkekengi has, for most of the year, a fairly uninteresting appearance. From August onwards however, the calyces, which surround the fruit and give the appearance of lanterns, start to take on their stunning red-orange colour and grow up to 2in (5cm) long. Cutting for flower arranging should be done as the colour of the calyces changes but if left on the plant they can become skeletonized.

Physalis can be sown under glass, in early spring, and used as an annual, being discarded after the lanterns are cut. When grown as a perennial, plants will die down after the first frost, and emerge early the following summer. The plant tends to have weak stems and can benefit from a few support stakes.

The Chinese lantern will grow in sun or shade, but the best crop of lanterns is obtained on plants in full sun, where the fruits will have formed early. Restrict the spread of this plant by cutting back any roots, which have spread further than 12 in (30cm) from the main plant. Cut deep into the soil with a sharp spade, then dig up and burn the roots.

Growing Requirements

Soil
This plant really will grow in any soil, but grow Physalis in a free draining soil, rich in organic matter for best results. Although established root systems will survive in the driest of conditions, growth is most rampant in moist soil.

Size
Physalis alkekengi can reach a height of 18in (45cm) with a spread of 2ft (60cm).

Propagation
The easiest method of propagation is to lift and replant a handful of roots in the spring or autumn. Chinese lanterns may also be grown from seed sown in the spring.

Family: Solanaceae
Genus: Physalis

Ferns – Hart’s Tongue Fern (Asplenium Scolopendrium)

Tuesday, March 31st, 2009

The Hart’s Tongue fern is a quite distinct form of fern, in that it has broad, strap-like fronds, quite unlike the delicately cut types of more familiar varieties. They have a short stem and can grow to any length from 4 to 24in (10 to 60cm) depending on where you plant them. The shorter ones are usually found growing in walls or crevices. They are also known under the name Phyllitis scolopendrium.
hart's tongue fern
The leather-like, bright green fronds make this a good foliage plant. It is a woodland plant and will always look good in a shady position, especially on banks, walls, or fallen trees. It is a British native plant and can often be seen growing under hedges or outcrops of rock. There are several varieties that have either wavy or crimped edges to their fronds, while others have a crested tuft at the top of the blade.

In spring, young plants can be planted out and if you want to plant them as a group, set them about 12in (30cm) apart. When the fronds first unfurl, they are covered with glistening white scales. These will turn brown and disappear as the fronds age. These are extremely hardy ferns and will grow in most climatic conditions, except where it is very hot and dry. They need very little attention apart from the tidying up of any dead leaves.

Growing Requirements

Soil
These plants are very accommodating and they will grow in either acid or chalky soils and will tolerate fairly dry conditions, but they are most at home in a moist, humus-rich, woodland type of soil.

Size
Asplenium scolopendrium can reach a height of 2ft (60cm) with a spread of 12in (30cm).

Propagation
The easiest method of increasing these ferns is by division in the spring. Sowing from spores in the autumn is possible, but it is a slow and complex method.

Family: Aspleniaceae
Genus: Asplenium

Shrubs – Buxus Sempervirens (Common Box)

Tuesday, March 24th, 2009

Common Box is a vigorous, evergreen, bushy, upright shrub or small tree and in many ways, is very uninspiring, producing green leaves and insignificant flowers, yet it is a very popular, widespread plant. The reason that it is so popular is that it makes excellent hedges, especially dwarf ones, and is superb for creating topiary specimens.
common box
As a free growing bush or tree, Buxus Sempervirens will not need pruning, but if used as a hedge or topiary shape, it will need trimming once or twice a year. The slowness and evenness of growth means that the shape of the plant is maintained for a long time without any maintenance.

Bare-rooted specimens can be planted out during the winter, as long as the weather is not too extreme. Container grown plants can be planted out at any time, but will need to be kept watered in hot weather. Once plants become established, there is no need for any extra watering. Box will grow well in sun or partial shade but can become drawn if there is too much shade.

As well as the main species, there are a large number of varieties. The main one of interest is Buxus sempervirens ‘Suffruticosa’, which is a dwarf form that is ideal for creating low hedges, which is excellent for outlining paths or beds. A lot of the others are variations in leaf colour, including variegated and golden ones, which can be useful for winter interest. The wood from Box is extremely hard and is sought after for making artists’ tools and for wood engraving.

Growing Requirements

Soil
Common Box will grow in most types of soil, including chalky ones, but will do best where the soil has had plenty of well-rotted organic matter added. It is quite a hungry plant and will need regular, annual mulches of compost or organic material to keep it healthy and vigorous.

Size
Plants, if left unclipped, can eventually reach a height of 12ft (3.5m) and spread up to 10ft (3m).

Propagation
To increase the number of plants, take semi-ripe cuttings in the summer and root them in a propagator or cold frame.

Family: Buxaceae
Genus: Buxus

Shrubs – Mahonia Japonica

Thursday, March 19th, 2009

Mahonia japonica is one of the most popular winter-flowering evergreen shrubs and originates in semi-woodland regions of China and Japan. It is closely related to berberis, but has larger, bolder leaves.
mahonia japonica
This evergreen Asian shrub has architecturally strong, angular leaves that are slightly spiny with the top surface a deep glossy green with a paler underside. Mahonia japonica will flower intermittently from late autumn through to early spring, providing 12in (30cm) long trails of blossom, which look splendid in floral arrangements. Once the worst of the winter weather has passed, its flower stems of primrose yellow blooms will continue to open, sending their strong scent into the air. It takes no more than one or two stems to fill a room with perfume. The blooms are followed by a display of blue-black fruits. It tolerates dappled sunshine, and even full sun in a north facing garden. In an area where summers are hot, plant out of the full sun.

Plant well rooted specimens at any time of the year, but not when in very dry, wet or frosty. While fully frost tolerant, Mahonia japonica should be planted in a sheltered spot out of the wind. The flowers are tough, but liable to be damaged if exposed to strong winds and the leaves will become scorched.

Pruning can help stop Mahonia from getting leggy and developing a less erect habit. Remove any thin and straggly growth in spring. When buying a new plant, select one with plenty of bud breaks from the base.

Growing Requirements

Soil
Grow on slightly acidic to neutral soil and include some well-rotted organic matter and some horticultural grit on heavier soils. The plants will tolerate chalky soils. Moist soil conditions, but not overly wet in winter, will provide this shrub with the best growing conditions.

Size
Plants can reach a height of 8ft (2.2m) and spread up to 10ft (3m).

Propagation
Mahonia japonica can be propagated by taking semi-ripe cuttings in midsummer.

Family: Berberidaceae
Genus: Mahonia

Climbers – Humulus Lupulus (Hop)

Wednesday, March 4th, 2009

Hops are normally associated with commercial growing for beer making but they are also grown in many gardens as attractive climbing plants. The most popular is the golden hop, Humulus lupulus aureus that has attractive golden-green leaves.
humulus lupulus
Humulus lupulus is an easy-to-grow, hardy, native climber with lobed leaves that bear clusters of fragrant, green female flowers from July to September. Make sure you buy a female plant, as male and females grow on separate plants. The leaves on the main stem are around 4 to 5in (10-15cm) long.

Plant out in spring to the same depth as it was in its pot. It may be a bit slow to get started, taking two or more years to reach its full potential. Once settled, it will set out from the ground each spring, and by midsummer will have put on 15ft (4.5m) or more of leafy growth. These plants prefer a deep, well-fed soil and don’t like to become too dry. Keep them watered in excessively dry periods.

Hops have very rough stems and leaves, which can cause painful weals, so avoid pushing through or against the plant unless your skin is covered.

Growing Requirements

Position
Although hops will accept a little light shade, they’re best to grown in full sun, especially the golden variety, as the golden colour of the foliage will turn green. They can be planted in various positions; against walls, draped over a fence or through an old shrub or tree. A tripod of poles makes an ideal support in a border setting.

Size
Hops will grow to around 20ft (6m) and spread 13ft (4m).

Propagation
Hops can be increased by taking runners that arise from the crown just below the soil surface or by dividing the roots in the spring.

Family: Cannabaceae
Genus: Humulus

Shrubs – Buddleja Davidii (Butterfly Bush, Buddleia)

Monday, March 2nd, 2009

Buddleja davidii is a favourite, fast-growing shrub from China. They not only make beautiful shrubs, but they also attract large quantities of butterflies to their nectar-rich flowers, which is how they derive their common name.
buddleia
The fragrant flowers are borne in long spires in the late summer and early autumn, after most other shrubs have finished flowering. The most typical colour of the flowers is lilac, but there are lots of shades, varying from white to pink to deep purple. The flowers can look a little unsightly once they begin to fade and turn brown.

Buddleja are best planted out in spring, although container-grown plants can be planted out at any time, as long as the weather is not too hot or too dry. They are relatively hardy plants and will withstand most winters, although an occasional harsh one may cut them back.

Butterfly bushes must be pruned regularly, otherwise the flowers will decrease in size and the plant will tire and die. Each spring, cut back the previous year’s growth to within 3 to 4in (7.5 to 10cm) of where it started. This may seem rather drastic, but the bush will soon recover and start sprouting new growth.

Growing Requirements

Soil
The butterfly bush is an undemanding plant and will grow on a wide range of soils, including quite dry ones, as long as it is planted in a sunny position, though a little light shade will be tolerated.

Size
Buddleja will grow to a height of 13ft (4m) and spread to a similar size.

Propagation
Buddleja will self-seed and the resulting seedlings can be transplanted and used as new plants. To propagate favourite colour forms, it is essential to take cuttings from existing plants. These are best taken as hard wood cuttings in the early winter months but summer cuttings from soft, new growth can also be used.

Family: Scrophulariaceae
Genus: Buddleja

Perennials – Bergamot (Monarda)

Saturday, February 28th, 2009

A mass planting of Bergamot can’t fail to impress. They bear curious, striking flowers in strong colours and have fragrant foliage. The leaves, when crushed, produce a wonderful aromatic perfume unlike anything else.
bergamot
Although the most popular flower colour is scarlet, Bergamot comes in a wide range of colours, including pink, purple, mauve and white. The flowers are hook-shaped and appear in whorls around a dome shaped head while the leaves are oval shaped. It is quite difficult to weed around the plants, as the roots grow close to the surface.

Bergamot looks best in a herbaceous border and goes well with other plants. ‘Cambridge Scarlet’ is one of the most popular varieties and has, unsurprisingly, scarlet flowers. A similar pink-flowered plant is ‘Croftway Pink’. There is a also pure white form known as ‘Snow Maiden’.

In the winter, Monarda will be just present above the soil as a mass of small leaves. They are to be immune to frosts and require no special care. In exposed areas, the plants may need to be supported by stakes. The plants should be cut down to the ground after flowering, and mulched with manure each winter.

The leaves can be simmered in water to make a refreshing bergamot tea. The flowers have a similar scent to that of the bergamot orange (which is used to flavour Earl Grey tea), hence the plant’s common name.

Growing Requirements

Soil
These plants like full sun or very light shade and will thrive in most types of soil, except in clay or where the soil is very dry. They will need to be kept well-watered over the summer.

Size
Bergamot can range in height from 3ft to 5ft (90cm to 1.5m) with a spread of around 18in (45cm).

Propagation
Monarda can be divided in the spring, as they start growing. This will rejuvinate old clumps and provide new, vigorous plants. Cuttings can also be taken when the plant is producing fresh and vigorous growth.

Family: Lamiaceae
Genus: Monarda

Perennials – Yucca Gloriosa

Sunday, February 22nd, 2009

Yucca Gloriosa delights in having several descriptive common names - Spanish dagger, Adam’s needle, palm lily and Roman candle. It is an evergreen shrub, but is often considered to be a hardy perennial by gardeners. In colder districts, they will need be grown in tubs and over wintered under cool glass.
yucca gloriosa
The plants have an exotic appearance, a tall, conical flowering spike, erupting from a base of sword-like grayish, green leaves, which immediately catches the eye. They make excellent plants where a focal point is needed or they can be used as an accent plant in a border. The flower spike appears in late summer, and carries an abundance of creamy-white, cup-shaped flowers, sometimes edged with crimson.

Apart from cutting off any dead foliage, or fading flower stems, Yucca Gloriosa needs little attention. Young plants, or offsets, should be planted out in spring, so that they have a full growing season before facing a cold winter. The ends of the leaves have very sharp spines so this needs to be considered if children play in the garden.

Growing Requirements

Soil
Well-drained soil is required but it does not need to be rich, as palm lilies will grow in quite poor conditions. They can withstand drought, so there should be no need to water after the plant is established.

Size
Yucca Gloriosa will grow to a height of around 6.5ft (2m) with a spread of 4ft (1.2m). The leaves are around 2.5ft (75cm) long and 2in to 3in (5cm to 8cm) wide.

Propagation
Sow seed in spring under gentle heat. Root cuttings can also be taken in winter, by cutting one or more of the thick roots into 2in (5cm) sections and placing them in compost. Another method is to remove some of the offsets from around the edge of the plant and pot them up.

Family: Agavaceae
Genus: Yucca