How to care for orchids: and a big watering mistake to avoid

Our expert pruning and watering hacks include a top tip to keep them flowering from Alan Titchmarsh

If you’ve ever tried to research how to care for orchids, you’ve probably been met with a lot of contradictory information.  

That’s not surprising. According to Kew, there are nearly three times as many orchid species as there are species of bird alive on Earth today (around 28,000). Considering you can find them on every continent, in all types of growing habitat, there will be many different ways to help any species that can survive indoors thrive. 

Hands and orchid flowers on windowsill close upCredit: Shutterstock / Serhii Ivashchuk
Moth orchids are often found on sale in supermarkets

Orchids are incredibly delicate and sought-after plants. With so many different types available, it’s no wonder that people assume they’re going to be too difficult to look after. This can put us off from buying and caring for them. 

You may be familiar with the moth orchid (also known as phalaenopsis). This the pretty variety usually on sale in supermarkets, generalist garden centres and DIY stores.  

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Though native to parts of Australia and southeast Asia, the moth orchid has become a UK houseplant favourite. It has been cultivated commercially as it’s relatively easy to look after. While shops may sell many types of hybrid orchids, it’s the moth orchid you’re most likely to come across. 

couple are choosing potted orchidat garden centreCredit: Shuttestock / adriaticfoto
There are things to watch out for when you’re choosing an orchid

How to care for moth orchids – before you buy

Avoid these tell-tale signs of neglect

Often, we see moth orchids bearing delicate flowers on display near the till at a supermarket or DIY store. Their petals, which can be gently speckled or blotched, are hard to resist. 

But knowing what to look for (and what to avoid) before you buy an orchid can really make a difference when it comes to keeping them alive and flowering for as long as possible at home. 

Moth orchid leaves turning yellow due to root rotCredit: Shutterstock / Nadya So
Yellow leaves are a sign of root rot

Zane Rappa, of the Orchid Society of Great Britain, explains what to look out for:

These tropical orchids need temperatures between 15-35°C (59-95°F). If it’s a chilly autumn day, and the orchids are placed outside or near the door, it’s likely they are already going to be quite damaged.

Don’t choose a plant that has yellow leaves. It doesn’t matter how beautiful the blooms are – it means the plant has started to rot. 

The perfect time to buy an orchid is when half of the spike (stem) is still in bud and half of the flowers are open. Plants like this can continue to bloom for up to three months. 

You want to see robust, sturdy roots – take one between your finger and gently squeeze it. If it feels mushy and is brownish in colour, cut it off with sterilised scissors when you’re home. Tidy the whole root ball, rinse it off in the sink or hose it down in the garden. You might need to repot it, if necessary, as soon as the blooms fade. 

 

Check if the orchid is growing in a synthetic plug (or even full sphagnum moss), the Orchid Society of Great Britain advises. Though orchids can grow like this in a commercial greenhouse setting, it might suffer in general home conditions. 

How to care for orchids: the essentials

Create the right conditions for growth

While there are some specific care tips for moth orchids, here are some general rules that will apply for most common orchid houseplants: 

  • Grow in a bark/woodchip-based compost, rather than traditional compost. Westland Peat-free Orchid Compost, £3, from B&Q is perfect for the job. 
  • Place in bright, but not direct, sunlight. A north- or east-facing windowsill is ideal.  
  • Mist them regularly with collected rainwater. Cooled, boiled water is also useful. Avoid tap water if possible as it’s too high in salts, minerals and sometimes also chlorine.  
  • Water regularly but don’t let the orchid stand in undrained water. 
  • Don’t place near a cold draught. According to RHS this could cause the orchid’s flower buds to drop. 

How to care for orchids when watering

Why it’s crucial to avoid overwatering

Did you know that moth orchids differ to other orchids that grow in the ground, because they have ‘air roots’ (they’re also known as epiphyte orchids)? This means that in the wild they grow above ground, using their roots to hold onto treesalthough they’re not parasitic. These air roots are coated in velamen. This is an outer layer of empty cells that help the plant absorb light and water from the atmosphere. 

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man repotting moth orchid with damaged rootsCredit: Shutterstock / olenaa
If overwatered, moth orchid roots can rot, like this

This means moth orchid roots can easily rot if they’re overwatered or left to sit in water. It’s also why they’re often sold in transparent plastic pots. It might be useful to repot your moth orchid every couple of years. 

How to water an orchid the right way 

While there are some rules of thumb to follow, as with all plant care, it helps to develop your own watering routine based on your observations of your orchid’s likes and dislikes. 

There are sources that suggest putting ice cubes on an orchid’s root ball every few days, but moth orchids don’t like cold temperatures so you should avoid this.

The Orchid Society of Great Britain advises that you want your orchid to have a perfect balance between being wet and dry.  

“What usually works best it to wait until the [bark-based compost] becomes dry and you can clearly see roots are silvery-white in colour,” the organisation says. “You can then take your orchid to a sink to flush through with water, or if you have it in a decorative pot without holes, fill it up to the top and let it soak for a while. Drain it, shake gently, blow off any water that could have gathered on or between the leaves and put it back in its usual spot.” 

To keep your orchid as healthy as possible, wait until the plant has dried out again, then repeat this process. 

Woman looks closely at white moth orchid growing on her windowsillCredit: Shutterstock / Ragemax
Pruning your orchid properly will make it more likely for more blooms to grow

How to care for orchids after flowering

Top tips to encourage future blooms

Moth orchid flowers will hopefully last a few months, provided you’ve not purchased one that’s damaged, followed the correct watering rules and placed it in a spot that suits it in your house. 

But what happens when the flowers fade? Thankfully, there’s a pruning trick from Alan Titchmarsh which might help your moth orchid bloom once again. You just need to wait until the stalks have nothing left to show. 

“The temptation is to whip the stems off now that the flowers are gone, right at the bottom,” he says in a video on Gardener’s World. “Don’t you dare! If you look down the stem, you’ll see scales [or nodules] every so often. They’re surrounding buds, and if you only cut back to where the stem has died as little, without going any further than that, then other stems can grow.” 

If a whole stem (or ‘spike’) has turned yellow, however, you won’t get flowers from this part of the plant again.  

Alan Titchmarsh isn’t the only fan of a low-maintenance orchid. Gardener and presenter Carol Klein was speaking from the RHS Hampton Court Palace Garden Festival in 2022 on BBC2, where she singled out the Vanda coerulescens orchid called ‘Exotic Purple’. 

This “straightforward” orchid, she said, “doesn’t even need any soil at all. All it needs is for you to occasionally spray it”. 

Temperature can affect re-flowering

The Orchid Society of Great Britain says you can expect your moth orchid to spike again when you notice the temperature drop. This tends to be in early autumn. The plant will then bloom in winter or spring. Blooms can potentially be induced by moving the plant to a colder place in your house regardless of season – for around two to three weeks – then pop it back in its usual, warmer spot. 

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Rosanna Spence

Written by Rosanna Spence she/her

Updated:

Rosanna Spence has been a journalist for nearly 10 years, reporting on a huge array of topics – from microwaves to cocktails, sustainable buildings, the Caribbean islands and beyond. She’s interviewed chefs at the helm of Michelin-starred restaurants and chatted to countless CEOs about their businesses, as well as created travel guides for experienced travellers seeking life-changing adventures.

Rosanna loves nothing better than getting under the skin of a topic and is led by an unwavering curiosity to share information and stories that inform and inspire her readers – a mission that has taken her around the world. Throughout her career, she has created content for Business Traveller, i-escape.com, Pub & Bar, BRITA, Dine Out and many more leading titles and brands.

She turned her attention to the Homes sector as a result of an ongoing renovation and improvement project, which takes up a fair amount of her time outside of work. When she’s not comparing carpet samples or debating the pros and cons of induction hobs, you’ll find Rosanna exploring Bristol’s food and drink scene, obsessively watching horror films, or donning some walking boots and heading for the hills.

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