A guide to growing orchids, with tips on how to pick the best varieties for most parts of Australia
A Cymbidium orchid flowering during autumn and winter
Orchid flowers look delicate and magical but the plants naturally occur in some pretty tough environments, which makes many of them surprisingly hardy.
Different orchids have different growing needs. In the tropics, moth, slipper, cattleya and vanda orchids all thrive. Most of these will also grow further south as indoor plants or in a greenhouse.
Although they’re mostly found in temperate regions, dendrobiums and cymbidiums will do well anywhere frost-free, and you can try them in frosty areas if you have a greenhouse.
Landscape architect and TV host Brendan Moar says orchids are one of his all-time favourite plants.
‘They’re an amazing flower and I’m constantly asking myself what can I do with them,’ says Brendan.
‘Orchids are one of those plants you become captivated by and you try your hardest with, but you might fail spectacularly if they’re not the right ones for your area.’
Luckily, there are so many varieties, you can make the right choice for practically anywhere.
Potting up orchids
Containers with side drainage holes work well for orchids, as do plastic pots. All orchids like to sit tightly in their pots and prefer to not be disturbed, so let them become quite crowded before you repot.
Tropical orchids do well in hanging baskets. Cattleyas prefer pots that are wider than they are deep. Vanda orchids like timber baskets and clay pots, as they have roots that prefer to climb outside their container.
All orchids need a free-draining specialist potting mix, with most based on bark chips. Moth orchids like a richer mix. If the mix has added fertiliser, reduce additional feeding for the first year.
If you make your own mix, soak the bark chips in hot water for a day first to leach excess tannins, and talk to your local orchid club about the best mix for each type.
TIP Label each plant pot and if you’re repotting, include the date.
Orchids like to sit tightly in their pots
Care and maintenance
Orchids love humidity and most have similar basic needs but check the plant label for specific requirements.
Water as needed in hot dry weather and up to daily in summer, depending on the variety, and mist regularly. Part-fill a bucket then immerse the pot to brim level for 15 minutes. Most like their mix to just dry out between waterings but some, like cymbidiums, can dry out entirely. Slippers prefer constant moisture.
Fertilise according to orchid type. Mix the food with the water in the bucket you use to water the plant.
Position in filtered light, about 50%, in summer and full sun in winter, moving as necessary. All orchids need freely circulating air, without strong winds or constant draughts.
Zap aphids, scale and mealy bug by spraying with pest oil or remove by hand, and protect from slugs and snails. Good positioning helps prevent pest and disease problems.
To grow orchids indoors choose a well-lit spot, out of direct sunlight, as it can scorch the leaves. Stand the pots on a tray of gravel and water into the tray to create humidity, making sure the roots don’t touch the gravel.
Choosing the right orchid
There are thousands of orchid varieties available in Australia so we’ve listed the six most common to help you choose a type to suit your zone conditions.
TIP In Tasmania and the mountains, you’ll need a greenhouse even for cymbidiums.
Super easy to grow in most regions, cymbidium flowers range in colour from deep chocolate to citrus yellow. Feed weekly with high-potassium, full-strength fertiliser from August to December and a high-nitrogen fertiliser the rest of the year.
TIP Move to a higher, lighter position if the plant is not flowering.
Pink cymbidium orchid
Dendrobium orchids are top picks for temperate regions. There is a huge range of species and cultivars, so check the specific light and growing needs of your particular dendrobium. Feed fortnightly from October to April with half-strength orchid fertiliser, and protect from excess water in winter as buds form.
Temperate-growing dendrobium orchids
At home in a tropical shadehouse, moth orchids are more often found in bathrooms and living rooms around the country, and the blooms can last for up to three months. Feed fortnightly year-round and ensure they have rich, moist potting mix and warm, humid conditions in filtered light, away from direct sun.
Tropical white moth orchid
Shade-loving slipper orchids prefer low to medium light, though some varieties can handle more. These tropical plants love humidity and don’t cope well without water. Feed fortnightly except when dormant with half-strength fertiliser.
TIP Too much sun causes yellow leaves, too much shade causes no flowers.
A slipper orchid with petals unfurled
Happiest in the tropics, vandas can grow further south if kept dry over winter. They have air-loving roots that roam outside their pots and need protection from damage. Feed weekly using high-potassium fertiliser from September to March.
TIP Partner with Spanish moss and bromeliads to keep the humidity high.
Vanda orchid thriving in tropical conditions
Truly tropical, these orchids won’t grow below about 10°C. If your area drops a degree or two below this, try them indoors. They like bright filtered light, but leaves yellow and growth slows if they get too much. Feed weekly with quarter-strength fertiliser when the plant is in active growth and showing green tips.
Cattleya orchid blooming in the tropics