Few houseplants can match the stunning flowers and dazzling colours of orchids. Orchids have a reputation as difficult or fussy plants, but they can be easy to care for if you follow some simple rules. In this comprehensive guide, we’ll talk all about how to care for orchids.
What are Orchids?
Orchids are flowering houseplants prized for their incredibly colourful flowers. Orchids come from the Orchidaceae family, which contains as many as 28,000 species. Of course, not all of these species are cultivated as houseplants. Most indoor orchids come from a few specific genera such as Phalaenopsis, Cattleya, Dendrobium, or Vanda.
Orchids form an extensive family of flowering plants called Orchidaceae. There are approximately 28,000 recognized species of orchids across at least 760 genera. Orchids can be found in various climates around the world. Most orchids come from tropical rainforests but there are some temperate species as well.
Appearance and Characteristics
Orchids are perennial herbs that grow as epiphytes or from rhizomes or tubers. Orchids are divided into two main groups – monopodial and sympodial. Monopodial orchids emerge from a single vertical main stem, while sympodial orchids grow from multiple stems or pseudo-bulbs.
Orchid flowers have a symmetrical construction with three petals and three sepals. One of the petals forms a lower lip known as a labellum which attracts pollinating insects. The flowers often have intricate patterns and come in a wide range of colours. Orchid flowers can last for months and many species also have strong scents.
Common Orchid Types
Also known as moth orchids, Phalaenopsis orchids are the most widespread species on the market. Phalaenopsis orchids are monopodial and are native to Australia and Southeastern Asia. Most Phalaenopsis species are epiphytes.
Cattleya orchids are large, showy orchids with stunning flowers. Cattleya orchids come from South America and are sympodial orchids. The labellums of Cattleya orchids are usually a different colour and shape than the other sections of the flower.
Cymbidium orchids are sympodial orchids that are usually epiphytes or lithophytes (which grow on rocks). Often known as ‘boat orchids’, Cymbidium species are found across Southeast Asia and Australia. Like Cattleya species, the labellums of Cymbidium orchids are different to the other petals.
The Dendrobium genus is one of the largest groups of orchids. These orchids are sympodial and are native to Southeast Asia and Australia. Dendrobium orchids tend to be epiphytes and have egg-like labellums.
Vanda orchids have large, exquisite flowers with strong fragrances. These orchids are monopodial and are indigenous to Southeast Asia and the Pacific. Vanda orchid flowers can last for a few weeks and typically bloom every few months.
Quick Care Summary
- Care Level – Easy to Moderate
- Sunlight – Bright, indirect light
- Watering – Approximately once per week
- Humidity – Moderate to high
- Temperature – Approximately 15 to 29ºC
- Soil – Specialised orchid mixes
- Soil pH – Slightly acidic (5.5 to 6.5 pH)
- Fertiliser – Once per month during the growing season
- Repotting – Every two or three years
- Pruning – Prune back after flowering
How to Care for Orchids
Most orchid species need bright, indirect sunlight. East-facing windows are ideal for many orchid species. Orchids that grow in clear pots, like Phalaenopsis orchids, need bright indirect light to allow their aerial roots to carry out photosynthesis. Vanda orchids are one species that requires full sun.
Correct watering is one of the most important things when caring for orchids. Orchids can easily suffer from overwatering, which causes root rot and other problems. Most orchids should be watered once every 7 to 10 days if most of their soil feels dry.
When watering orchids, allow the soil to dry out almost completely before watering deeply. This gives the orchid enough time to dry out, which helps prevent root rot. Test the growing medium with your finger or a hygrometer to check how dry or wet the medium is. Always use a pot with drainage holes to allow excess water to escape.
Humidity & Temperature
Most orchids require warm, humid environments to thrive. Daytime temperatures for orchids should range from approximately 15 to 29ºC, depending on the species. Avoid placing orchids in locations where they’re exposed to dry or cold drafts from windows or radiators.
Many orchids require moderate to high humidity levels, usually ranging from 40 to 70%. It’s possible to boost humidity by misting the foliage every few days, using a humidifier, or placing the orchid’s pot on a pebble tray filled with water. When misting, take care not to get any water on the flowers as this can cause problems.
Soil & Orchid Mix
Orchids usually require a specialised soil mix that is usually quite loose. Orchids also require plenty of airflow around the roots as this helps prevent root rot. Orchid soil mixes tend to use bark because this dries out quickly and helps keep the soil aerated. Sphagnum moss is also used to help retain some moisture. Orchids also require slightly acidic soil with a pH range between 5.5 and 6.5
Orchids benefit from extra nutrition, but only require small doses of fertiliser. The American Orchid Society recommends feeding orchids weekly with a ¼ strength dose of fertiliser. However, you can feed every two to four weeks if that’s easier. Fertiliser should be applied from spring until autumn.
Use specialised orchid fertiliser wherever possible and keep an eye on the dose. Always water the orchid before applying fertiliser. If you apply too much fertiliser, the extra chemicals and salts can burn or damage your orchid.
Orchids prefer to be slightly rootbound in their pots, so don’t require frequent repotting. Orchids should be repotted every two or three years during the spring. If the roots have started spilling over the edge of the pot, the orchid should be repotted into a larger container. Only increase container size by one or two inches each time. Use fresh growing medium and avoid compacting the soil mix.
Growing in the garden
In some climates, it’s possible to grow orchids in the garden. Orchids cannot tolerate cold environments, so do best when planted underneath the shade of trees during the summer. In warmer areas, orchids can also be grown in outdoor pots in the winter.
Provide a sheltered spot to protect the orchid plants from strong winds. Don’t plant orchids outside when there is a risk of frost. Cattleya, Cymbidium, and Vanda orchids all perform well outside.
How and When to Prune Orchids
How and when to prune an orchid depends on the exact variety of orchid that you have. Phalaenopsis orchids can have a secondary bloom from old flower spikes. Deadhead these orchids during the growing season to encourage new flowers. In the autumn, prune back the flowering spikes to about an inch long. Always make the cut about half an inch above a node to allow new blooms to appear.
Dendrobium orchids produce flowers from old stems. With Dendrobium orchids, deadhead spent flowers. Generally, Dendrobium orchids won’t have a second bloom from the flower stems. Dendrobium orchids should not be pruned back hard after the flowering season – leave the stems in place.
Before pruning a flowering spike, make sure all the flowers have finished or fallen off. Most orchids will only need to be pruned once per year when flowering has finished. Remove any stems or roots that are brown or have started yellowing. Don’t prune any of the healthy white roots.
Trim off any diseased or damaged leaves and roots to maintain a healthy orchid plant. When removing leaves, cut right back to the base of the leaf where it joins the main stem.
Problems with Orchid Plants
Although they are fairly tough plants, orchids can still be vulnerable to a range of diseases and pests. Here are the main ones to look out for:
Also known as botrytis, orchid blight is a fungal issue that manifests as brown spots on flowers, leaves, or stems. Orchid blight is usually caused by overwatering. Use a baking soda solution or neem oil to combat the disease and only water the orchid when the soil is almost dry.
Root rot is a common problem for many houseplants, but orchids are particularly susceptible to it. Root rot is caused when there is too much moisture around the roots, often as a result of overwatering. Brown, smelly or mushy roots are the main symptoms, along with yellowing stems and foliage.
Allow the orchid to dry out more before trimming away the brown roots. Then water the plant and allow it to dry out in between watering.
Mealybugs are small white insects that often target houseplants like orchids. They feed on sap, which impairs the growth of an orchid plant. Use neem oil or a damp cloth to remove these pests.
Similar to mealybugs, scale insects suck sap from orchids, causing growth problems. Scale insects have hard shells and congregate in clusters. Neem oil can be used to remove infestations. Wiping the orchid with a damp cloth will also get rid of them.
Another common houseplant pest, spider mites leave behind sticky white webs on leaves and flowers. Affected orchids may also develop brown or yellow spots on the leaves. Spider mites may target your orchid if there isn’t enough humidity around the plant. A spray of water or a neem oil solution should remove them.
How to Propagate Orchid Plants
There’s no one-method-fits-all when it comes to propagating orchids. Sympodial species, like Cattleya and Dendrobium orchids, can be propagated by division. Monopodial orchids like Vanda orchids are better suited to cuttings.
Propagating by division
- Propagating an orchid by division is best performed when you’re repotting the plant.
- Water the orchid to make it easier to remove from the pot
- Gently extract the plant from the pot and clear away the soil from the roots. Look for sections that have at least three bulbs (also known as pseudo-bulbs).
- Once you’ve chosen where to divide the orchid, gently tease each section apart with your hands or cut them away from the plant with a sterile tool.
- Remove any bulbs that have dried up or are breaking down.
- Pot up each divided section into its own pot
Propagating by cuttings
- Choose a healthy stem between 10 and 12 inches long. Make sure the stem has several nodes and avoid using flower spikes.
- Using a sterile cutting tool, cut the stem where it joins the base of the parent plant
- Dip the end of the cutting in rooting hormone to help the process and protect against infections
- Wrap the end of the stem in some sphagnum moss. Water the moss to ensure that the cutting gets enough moisture
- Place the cutting in a vessel to allow roots to form under the moss.
- Enclose the cutting in a polythene bag to create a humid environment
- Keep the moss watered until roots have started to sprout
- Once the cutting has produced two or three inches of roots, pot the cutting up in some orchid mix.
Facts About Orchids
How big do orchids get?
The size of most orchid species varies between 8 and 36 inches. The exact size depends on each species.
What are orchids good for?
Orchids are fantastic ornamental houseplants due to their impressive flowers. Orchids can also have other benefits such as purifying the air, helping to reduce stress, or being great for feng shui.
Are orchids poisonous to pets?
Orchids are not poisonous to pets like cats and dogs. Orchids are also not considered to be toxic to humans.
How fast do orchids grow?
Most orchid species grow fairly slowly, sometimes only producing a few new leaves every year. This is due to orchids having a lower metabolic rate than many other plants.
Orchid flowers are simply breathtaking. Many orchids produce fairly large flowers with pungent scents. Orchid flowers are usually symmetrical, with three main petals and three sepals. The bottom petal is known as a labellum and helps attract pollinators.
Orchid flowers come in a huge range of colours including blue, green, pink, purple, red, white, and yellow.
Uses of Orchids
Aside from their ornamental beauty, orchids also have several other uses. Orchids are frequently used to make scented products and perfumes, especially species like Cattleya orchids. Vanilla plants are also members of the Orchid family and have several culinary uses.
Orchids have several benefits when used as houseplants. Studies have shown that plants like orchids can help reduce stress, boost productivity, and help us sleep. NASA’s Clean Air Study also shows that Dendrobium orchids could remove VOCs like formaldehyde, toluene, and xylene from the air.
How much light do orchid plants need?
Most orchid plants require bright, indirect light. Some species, like Vanda orchids, require more direct sunlight.
Where should I place my orchid plant in the house?
East or south-facing windows are ideal for orchid plants. Avoid placing orchids in draughty areas near radiators or air vents.
How do you transplant orchids?
Remove the orchid from its old pot and brush off the old soil. Trim away any dead roots and repot the orchid in a container that’s one or two inches bigger.
How do I keep my orchid blooming?
Phalaenopsis orchids are one of the only types that can flower again during the season. To keep blooming, these orchids need warm, humid temperatures and plenty of bright, indirect sunlight. Watering and fertilising correctly also help keep the orchid blooming.
When should you repot an orchid?
You should repot orchids every two or three years or if the roots have started growing over the edge of the pot.
Orchids are extremely beautiful houseplants that are believed to be difficult to care for. Thankfully, caring for orchids is fairly straightforward if some basic rules are followed. Avoid overwatering your orchid and provide plenty of bright, indirect light. Use a specialised orchid potting mix and enjoy your orchid for many years!