Cortaderia Selloana, commonly known as pampas grass, is a tall grass native to southern South America, including the pampas after which it is known in Patagonia. Here it is the premier wild grass. It is very tough and adaptable, but prefers a sunny spot, with good air circulation and a reasonably fertile well-drained soil.

Pampas grass adds interest to the garden from September to February, as this is when its feathery plumes grow high above the dense clump of foliage. The grassy leaves are evergreen, coarse and edged with sharp teeth, which are capable of inflicting a nasty cut. This feature makes it suitable for planting as an intruder deterrent along a boundary. The leaves are usually bluish green, but can also be silvery grey.

The plant forms a dense clump of foliage, from which the flower spikes begin to form in midsummer. The plumes eventually open completely when the stems are almost fully extended, and range in colour from silvery white to buff depending on the cultivar.


Growing Requirements

Soil
Cortaderia Selloana prefers fertile well-drained soil. It does not like to be too wet and is incredibly drought tolerant.

Size
Pampas grass forms a large mass of foliage 3 to 4ft (90 to 120cm) high and around 5 to 6ft (150 to 180cm) across. The long, slender leaves are 3 to 6.5ft (1 to 2m) long and the flower plumes grow to 8 to 16in (20 to 40cm) on top of a 6.5 to 10ft (2 to 3m) tall stem.

Propagation
Divide a section of the plant from the parent, using a sharp spade, in either spring or autumn. Then put into a pot or plant directly into prepared garden soil.

Family: Poaceae
Genus: Cortaderia

Dicksonia Antarctica is the best known of all tree ferns originating in Australia and Tasmania. It has been grown in Britain for many years for its ease of cultivation, great beauty and hardiness. It is named after James Dickson, 1738-1822, a Scottish nurseryman and botanist.

It will tolerate some degree of exposure to sun, but dislikes very strong winds. Pick a sheltered spot in the semi-shade for optimal, maximum growth. Whilst this tree fern is hardy to around -10°C, winter protection is recommended by covering the crown with straw or leaves. The trunk should be watered frequently during dry weather because the roots of tree ferns actually travel down the inside of the trunks of the plants. The foliage appears at the top of the trunk in spring, and unfurls from the centre into large, dark green fronds.

Growing Requirements

Soil
Dicksonia Antarctica thrives in filtered sunlight and well-drained, aerated soils with lots of organic matter and water and prefers damp sheltered woodland. It will withstand some drying out and can survive in dry conditions.

Size
These ferns can grow to 50ft (15m) in height, but more typically will reach about 15 to 17ft (4.5 to 5m) in the UK with a growth rate of about 2in (5cm) per year.

Propagation
Propagation is mainly from spores, but plants can also be grown from plantlets occurring around the base of the rhizome. The spores can be sown at any time on the surface of a finely-sifted loam and peat mix in well-drained pots which need to be kept moist and covered with a sheet of glass.

Family: Dicksoniaceae
Genus: Dicksonia

The Gazania is native of South Africa and is sometimes known as the Treasure Flower. They are half-hardy perennials but seldom survive a British winter and are best grown as annuals. They make useful summer bedding plants or they can be grown in patio containers or hanging baskets. Wherever you plant them, they will provide a superb splash of colour on sunny days.

Gazanias have a daisy-like flower and come in lots of brilliant colours, pinks, yellows, oranges and reds, and often a mixture of these and sometimes have a metallic sheen. The vivid flowers close up on an afternoon and remain shut until the following morning. If the weather is overcast, they do not open at all. The leaves are lobed, dark green, and grow in compact clumps. Each clump supports a number of flowers.

Growing Requirements

Soil
Water freely when in growth but keep plants just moist in winter outdoors. They like sandy well-drained soil in full sun and will tolerate coastal conditions. Deadhead to prolong the flowering period.

Size
Gazanias will grow to a height of around 10 in (25cm) and spread about 13in (33cm). The flowers can reach a diameter of 10cm and bloom from June until the end of September.

Propagation
Treasure flowers are very easy to grow and are normally grown from seed in a loam-based compost with added sharp sand, under glass, in late winter or early spring at 18 to 20°C although they can be grown from basal cuttings.

Family: Asteraceae
Genus: Gazania

The silver birch is a genuine, native deciduous tree of the British countryside. Sometimes known as “Lady of the Woods” due to its graceful appearance, it is not a long-lived tree as most specimens become diseased or die by the age of 70. In the wild, it is a pioneer species, and will take over open areas or newly disturbed ground.

It has papery-white bark, which darkens and cracks as the tree ages, which leaves it prone to attack by the birch polypore fungus Piptoporus betulinus. The leaves of the silver birch are small, toothed and roughly diamond-shaped. Betula Pendula bears male catkins in early spring that can be as long as 4in (10cm) and their pollen is released in clouds during April. The emerald green leaves emerge shortly after and turn a golden colour before falling in the autumn.

Silver birch is ideal where only dappled shade is required as it has an open habit, allowing a range of plants to be grown underneath it – ferns look rather attractive in this position. The twigs can be bound together to make traditional brooms called besoms and are reputedly flown by witches!

Growing Requirements

Soil
The silver birch tolerates a wide range of habitats, but grows best on dry sandy soils and does well in higher altitudes than most other broadleaved species.

Size
Betula Pendula is relatively fast growing and it can reach a height of 82ft (25m) with a spread of around 32ft (10m) at maturity which it will reach in about 40 years.

Propagation
Plants are normally grown from seed although they can be grown from cuttings. The seeds are brown and yellow flake-like and are wind dispersed.

Family: Betulaceae
Genus: Betula

Garrya Elliptica, commonly known as the silk-tassel bush, is an evergreen shrub with dark green, leathery leaves. In late winter through to early spring, it bears long, greyish-green catkins that can cover the whole shrub. Male and female catkins are on separate plants – the male catkins have pollen while the female plant has little brown berries.

The Garrya genus is native along North America’s western coastlands, from Mexico to Oregon. Garrya Elliptica is the hardiest species and the one best-suited to the British climate. They do not like having their roots disturbed, and will often die if moved too many times.

A commonly grown cultivar is ‘James Roof’ which is a strong, vigorous male variety and has large, leathery leaves with catkins up to 8in (20cm) long.


Growing Requirements

Position
It does well in shade against walls or fences, but is also suitable for the open garden in mild locations.

Soil
Garryas will flourish in most garden soils even dry or infertile soils. It needs well-drained conditions, and can be grown in coastal areas as it is tolerant of salt spray.

Size
Garrya Elliptica is relatively fast growing and it can reach a height of 13ft (4m) with a spread of around 10ft (3m).

Pruning
Plants can be trimmed to shape in late spring, after the catkins have fallen off.

Propagation
The plant can be easily propagated by taking 4inch semi-ripe cuttings in late summer and placing them in a sandy rooting compost.
Plants can also be raised from seed, which will need to be planted in a sandy loam during late autumn or winter, and will require three months of cold stratification for them to germinate. The seedlings will grow rapidly and should be pricked out into individual pots when they are sturdy enough to handle.

Family: Garryaceae
Genus: Garrya

Washingtonia Robusta is a very fast growing, architectural fan palm tree with a trunk that is swollen at the base, tapering to the top. It is the tree often seen in Hollywood movies and goes under the common names of Petticoat Palm, Mexican Fan Palm or Skyduster. They have large, green, fan-shaped leaves, which thrive in full sun and can grow as large as six feet long.

The Washington Palm can be planted close to the sea, because of its salt-tolerance, but it is only hardy down to about -5°C with some protection. They will not tolerate being planted in very cold or exposed sites.

The small fleshy flowers are produced in the late spring, followed by black-brown, small fruits. Each fruit contains a single seed with a thin, sweet pulp that tastes like butterscotch or dates. The lower leaves remain on the tree after they die, and create a brown, straggly covering beneath the living green leaves.

There is a hybrid called Washingtonia Fillibusta [Fillifera x Robusta] which has the best qualities of both parents. It has the cold tolerance of Filifera and the wet tolerance of Robusta.

Growing Requirements

Soil
Washingtonia Robusta will grow in most soil types, even in quite poor soils. Grow in full sun, though young plants will tolerate partial shade.

Size
It will ultimately reach 80 to 100ft (24 to 30m) in height and 10 to 15ft (3 to 4.5m) depending on the climate.

Propagation
The Mexican Fan Palm is one of the easiest palms to grow from seed and the seeds can germinate in as little as two weeks, but this would be reliant on a high germination temperature, maybe as high as 40°C. Decent germination is achievable at 25°C to 35°C. Soak the dry seeds for 2 to 3 days in warm water before sowing.

Family: Arecaceae
Subfamily: Coryphoideae
Genus: Washingtonia

This is the second part of the article describing the various ornamental plant groups.

Orchids
All orchids belong to the Orchidaceae family comprising around 25,000 species and more than 70,000 hybrids. Most orchid species come from tropical rainforests and often have fleshy, aerial roots. The most popular come from Asia, though there are many wild orchids in South America. The flowers often have fantastic colour combinations.

Bromeliads
Bromeliads are mainly rainforest plants, originating from the southern states of the USA down through to South America. Their structure is usually a rosette shape, with long, stiff (often variegated) leaves and striking blooms. They can be grown outdoors in warmer climes but are more often grown as an indoor plant.

Cacti and Succulents
Cacti and succulents come a fascinating variety of shapes and this is a result of them living in adverse conditions, often prolonged periods of drought. They range from small pincushion shapes to the familiar tall branching desert cacti. They will thrive in desert gardens but are mostly grown indoors in greenhouses or as houseplants.

Palms and Cycads
Palms are evergreen trees or shrubs often with big spiky leaves and bold foliage. They range in size from dwarf shrubs to tall, unbranched trees and mainly originate from tropical and sub-tropical regions. Cycads resemble palms or tree ferns in appearance but they are not related and are primitive seed plants.

Ferns
Ferns are primitive plants that produce evergreen or deciduous fronds. They like damp, shady places and can provide elegant symmetry and texture in a garden. Tropical ferns can be grown in a greenhouse or conservatory and make great specimens. Ferns do not flower and reproduce by spores rather than seeds.

Aquatic Plants
Aquatic plants are those that grow submerged, rooted or floating in water. Many aquatic plants are both functional and ornamental. They can suppress the growth of algae and provide a habitat for microorganisms while providing attractive foliage and flowers. A wide variety of plants can be used around small ponds, natural water features or boggy habitats.

Grasses and Bamboos
Grasses and bamboos are members of a vast family of plants that grow throughout the world. A few of the grasses are commonly grown as lawns, whilst others are grown in clumps for their height and wonderful flowering spikes. Bamboos are woody-caned, perennial grasses most of which originate in tropical and sub-tropical climates. There are a few hardy varieties from more temperate regions.

The Leyland Cypress tree is an accidental Victorian hybrid of the Nootka Cypress and the Monterey Cypress, first discovered and grown by C.J. Leyland in England, and is a very fast growing evergreen conifer. It makes a splendid dense hedge or an equally fine specimen tree and are among the most widely used hedge plants throughout the world.

The growth rate of Leylandii can be as much as 2.5-3ft (75-90cm) a year and if grown as a hedge or windbreak, it will need to be regularly clipped to keep it relatively low and narrow. To grow as a 6ft (1.8m) hedge, the planting distance should be about 2ft (60cm) apart. A rough guide for growing taller hedges would be to plant about a quarter of the proposed height apart.

Leylandii hedges are grown as either the common green variety or the golden Leylandii Castlewellan Gold. The golden variety grows slightly slower than the green one but will bush out more as it grows upwards so will still form a dense evergreen hedge quickly.

A scientific study to find the tree that was most effective at absorbing air pollution discovered that it was the Leylandii. It can absorb several times as much dust, smoke, and carbon dioxide as the average oak!

Growing Requirements

Soil
Leylandii will grow in most soil types, even in quite poor soils, as long as the soil is well-drained but it will not tolerate chalky soils. Grow in full sun or partial shade.

Size
If left untrimmed a Leylandii will ultimately reach 100ft (35m) and spread about 32ft (10m) by the time it is mature (10-20 years).

Pruning
The hedge will need to be trimmed a minimum of twice a year to keep it in shape. Make the last cut in either late summer or early autumn and wear gloves whilst cutting the hedge as the leaves can cause skin irritation.

Genus: Cupressaceae
Family: Cupressus

Lithops are remarkable little plants that are native to Namaqualand, a small area of South Africa. They grow in very dry desert areas, with their stems buried in the stony earth and only the tips of the stems visible. Lithops are commonly known as living stones, and they are capable of fooling humans and animals alike that they are real stones!

Lithops make an ideal plant for a collector. Because they are small and have a slow, compact growth habit, a large collection can be grown in a relatively small space. The main fascination provided by Lithops is the variety of colours and patterns of the plant bodies, although they will produce flowers under favourable conditions. There are around 200 varieties and cultivars known.


Growing Requirements

Temperature
As Lithops originate in a very dry, hot desert area, the temperature needs to be 25 – 35c during the summer and 10c or above over the winter. They can be kept cooler so long as they have plenty of light and the compost is dry but they will not tolerate frost.

Compost
Lithops are best grown in a terracotta type pot or bowl. General-purpose compost with some grit added to help drainage is suitable or any proprietary cactus compost. An occasional feed, as you would for a houseplant, is allowed but mustn’t be overdone, as Lithops require very little in the way of nutrients.

Watering
During the winter months, the plants only need water to prevent the roots from drying out completely – once a month should be fine. Watering should be increased gradually from March until late May when the plant should be in full growth. You can safely at least once a week during the summer so long as the pot is not allowed to sit in a tray of water. From late September, you should reduce watering to make the plant to go into a semi-dormant state and by November you should be back in to the winter watering regime.

Genus: Lithops
Family: Aizoaceae

Ornamental garden plants can be broken down into several different groups. Some of the groups overlap, for example, most trees and shrubs will also fall into the perennial group.

Trees
Trees are usually the largest and most prominent plants in a garden and form the backdrop that will influence the selection of other plants. Trees are perennial, usually having a single woody stem, and may be evergreen or deciduous. They are found in most parts of the world and so there is a huge variety of ornamental trees and plenty of choice for most types of garden.

Shrubs
Shrubs are woody-stemmed perennial plants, usually free-branching from the base rather than the single stem of a tree. As with trees, shrubs can be deciduous or evergreen, but they have a breathtaking variety of ornamental features such as shape, growing habits, striking flowers, eye-catching fruit and beautiful foliage.

Climbers
Climbing plants use other plants, rocks or man-made structures for support. These valuable deciduous or evergreen plants can be used to cover-up wall or fences or to provide ornamental screening. Some will have a self-clinging or twining habit whilst others will require ties or some sort of additional support.

Perennials
Perennials are plants that live for two years or longer and they will flower once they are mature. The term is most commonly used to describe garden plants that die back each year after flowering and seeding, issuing new growth in the spring. They can be grown in herbaceous borders, as specimen plants or in containers.

Rock Plants
Rock plants are a mixture of shrubs, bulbs and hardy perennials originating from mountainous regions. They grow on or among rocks and are suitable for a rock gardens. Rock plants are adapted to growing in thin, well-drained soil and at altitude. They can survive temperature extremes but not excessive wet conditions. Alpines are included in this group.

Annuals and Biennials
An annual plant is, as the name suggests, one with a lifespan of within one year. A biennial will normally only sport foliage in its first year, going on to flower, set seed and die the following year. These plants are free-flowering and are easy to grow from seed. They can be used as bedding plants, grown in containers or hanging baskets, or used amongst shrubs and perennials.

Bulbous Plants
Bulbous plants, more commonly know as bulbs, are grown chiefly for their beautiful flowers. They originate from all parts of the world and this group also covers plants with tubers, corms and rhizomes. Bulbs usually have a long dormant period that is often spent underground. Some bulbs can provide an early splash of colour in spring, some thrive in borders whilst others make great container plants.