A comprehensive guide to orchids
Orchids come in all shapes, sizes and colours and are grown for their bold and usually long-lasting flowers. Use these plants to brighten both indoor and outdoor spaces and add an exotic touch.
There are orchids that flower throughout the year and others that only flower at certain times of the year. Some are for experienced gardeners while others are ideal for beginners or those without much time. Easy-care orchids make welcome gifts and any orchid can be the beginning of a hobby or collection.
Despite the huge variety in colour and flower shape along with growing conditions, most orchids grow best in a container such as a pot or hanging basket with good quality, free-draining orchid potting mix made from composted bark. Some can also be grown mounted on boards or grown on tree trunks (trees that don’t shed bark) or on tree ferns.
Water occasionally and feed with a specialist orchid plant food when the orchid is actively growing (usually in spring). Repot when the plant outgrows its space (usually only every two to three years). This is also a good time to propagate orchids by division of an existing clump.
Pests can include orchid beetle, which can leave chewed and ragged leaves (remove by hand) and mealy bug, scale or two-spotted mite which may attack foliage and indicate that the plants are not growing in ideal conditions (may be lacking light or too dry). Apply a registered chemical control or a diluted oil spray to remove pests. Also protect plants from snails and slugs, especially when buds are forming. Regularly remove discoloured leaves.
Here’s a guide to some of the huge variety of orchids available and their best uses and features.
Brassia spp. and Hybrids (spider orchid)
These are tropical orchids that are adaptable to sheltered positions in warm climates. Grow outdoors in a frost-free position attached to a tree fern or tree trunk or mounted on a board or in a basket. You can also grow spider orchids in a hanging basket in a sheltered spot in a fernery. The flowers have long thin petals that resemble spider legs. Flower colours are mainly green and cream, often with contrasting patterns in a dark colour such as burgundy, with many hybrids available. Flowers are produced mainly in spring and summer. Good for beginner to experienced growers. Height: 20-30cm; width: 20-40cm.
Brassidium Hybrids (brassidium)
This is a hybrid between the spider orchid (Brassia spp.) and dancing lady orchid (Oncidium spp.) characterised by lots of long-lasting and colourful flowers including combinations of green, white and burgundy. Some varieties have a spidery look. Grow in pots or hanging baskets in a warm, brightly lit spot such as a fernery, conservatory or sheltered veranda. Brassidiums may bloom throughout the year with a flush of blooms in spring and summer. Best for experienced growers. Height: 20-30cm; width: 20-60cm.
Cattleya spp. (cattleyas)
The popular and colourful cattleya orchids originated in tropical America. Flowers are large (5-10cm across depending on species or variety) with many colourful combinations including pinks, white, cream, greens and yellows. The flowers have a distinctive orchid shape with five large outer petals and a central small trumpet (known as the labellum) often in a contrasting colour. Flowers are produced year round. Provide a spot that’s warm in winter, sheltered from wind and brightly lit all year such as a glasshouse, conservatory or fernery. Allow orchid mix to dry out between waterings, especially in winter. Best for experienced growers. Height: 10-60cm; width: 20-80cm.
Cymbidium spp. and cultivars (cymbidiums)
These are among the most popular orchids to grow in gardens and are usually grown in large pots positioned outdoors. Cymbidium orchids have large, robust stems of flowers in winter and early spring amid light green, strappy leaves. Flower colours include green, pink, magenta, yellow, cream, white and brown tones and the blooms may have distinctively marked patterns on the labellum. The flowers last for many weeks and can be used as an indoor potted decoration for up to six weeks while the orchids are in bloom. Keep outdoors in a brightly lit spot such as under the dappled shade of a tree. Lack of bright light especially in summer may hinder flowering. Cymbidiums come from the tropics, subtropics and even warm temperate zones with some species native to Australia. Repot every three years or when the plant has outgrown its container. Remove non-flowering sections (known as back bulbs) when repotting. Fertilise in spring and late summer. Ideal for beginners. Height: 30-120cm; width: 20-90cm.
Dendrobium spp. (rock lily)
There are many species of dendrobiums but the best known in gardens is the rock lily (Dendrobium speciosum), which is native to the east coast of Australia where specimens grow in large clumps on rocky outcrops in the bush. These orchids are adapted to growing on rocks but can also be mounted on boards or grown in pots or hanging baskets. Common flower colours are yellow or white with massed displays occurring in late winter and spring. There are also dendrobiums from tropical climates including the Cooktown orchid (D. bigibbum), which is the floral emblem of Queensland, and D. kingianum also from north Queensland. As well there are species from New Guinea and parts of Asia and many hybrids. Rock lily is ideal for beginners who want to grow a garden orchid. Tropical species are best for experienced orchid growers or those in a tropical location. The rock lily can grow to form clumps up to 1m high and 3m wide.
This orchid is a hybrid between Laelia spp. and Cattleya spp. with large, often flat flowers or with a distinct trumpet-shaped labellum in bold colours including bright pink and orange. This is a very showy plant for the experienced grower and may flower throughout the year. Grow in a well-drained pot such as a terracotta pot as for cattleya orchids. Height: 20-30cm; width: 20-30cm.
Oncidium spp. and Hybrids (dancing lady orchid)
This is a dainty orchid with long sprays of small orchid flowers often in yellow and brown produced throughout the year but usually in the warmer months. The dancing lady is often mounted on a board but can also be grown in a hanging basket. Best with shelter so grow in a glasshouse or other protected spot. Experienced growers. Height: 20-120cm; width: 20-90cm.
Phalaenopsis spp. and Hybrids (moth orchid)
This is one of the most popular gift and decorative orchids to grow indoors in a brightly lit room. Moth orchids should be sheltered from drying conditions (such as heaters or air conditioners) and misted occasionally in addition to watering when dry. Plants produce sprays with several blooms to a stem often in white, purple or pink but also yellows and creams. Some may have a chequerboard pattern. Once the flowers are finished cut back the stem to just below the last bloom and the stem will re-flower. Flowers can be produced throughout the year. Most commonly available moth orchids are compact in size. Suited to beginners. Height: 20-90cm; width: 10-60cm.
This orchid is a hybrid between Cattleya spp. and other orchids with large flowers, with narrow petals and a distinct trumpet-shaped labellum in bold colours including yellow and orange often with contrasting spots or other markings. This is a very showy plant for the experienced grower and may flower throughout the year. Grow in a well-drained pot such as a terracotta pot as for cattleya orchids. Height: 20-30cm; width: 20-30cm.
Sarcochilus spp. (fairy orchid)
This orchid grows in trees or on rocks and is native to parts of eastern Australia. It can be grown mounted on boards. You can also grow many fairy orchids in hanging baskets or pots in very free-draining mix. Grow in a shaded but humid position sheltered from frost, cold and excessive heat. Produces sprays of small colourful orchid flowers throughout the year in colours that include white, terracotta, purple and pink. Best for experienced growers. Height: 10-40cm; width: 10-40cm.
Native to South and Central America, this is an orchid grown for its large and cattleya-like flowers usually in pink or white with a distinctive labellum. Flowers can be 15cm across but are short lived. The flowers appear among large ribbed leaves. Grow in bright light indoors or, in a warm climate, outdoors in a sheltered but well-lit spot. Keep moist and provide increased humidity through summer (for example stand pots on pebbles in a tray of water). This is an orchid for experienced growers and collectors. Height: 30-120cm; width: 30-120cm+.