Why Your Moth Orchid is Dying and How to Save It
Our favourite orchid hands-down is the Phalaenopsis, commonly known as the moth orchid. You've almost certainly seen them — lining the shelves at Bunnings or sitting pretty in the gifting section at the front of your local supermarket, available in an impressive array of colours.
Sadly, most people treat them as disposable. They look stunning in bloom, but the moment the flowers drop, they get pushed to the back of the bench and left to fend for themselves. The truth is, with just a little know-how, a Phalaenopsis can rebloom regularly and thrive for years — and it's really not as hard as you might think.
It's Not Always Your Fault
The trouble often starts long before the plant reaches your hands though. Commercially grown Phalaenopsis are produced as cheaply as possible — basic pots, basic media, and kept that way until severely root bound. Repotting costs time and money, and besides, a stressed, cramped orchid is a flowering orchid — which is the whole point when you're trying to sell plants in bulk.
Then imagine going from a perfectly controlled greenhouse to the fluorescent glare of a supermarket aisle or the concrete chill of a hardware warehouse. That's a serious shock, and because retailers clear shelves within 48 hours, there's no recovery time built in.
The staff doing the watering are usually generalists with no specialist knowledge, looking after everything from herbs to succulents in one quick sweep. So by the time that beautiful plant catches your eye, it may already be stressed, waterlogged, and quietly struggling — and that's before it's even made it to your home.
First Things First — Don't Touch Those Spikes
After your plant has completely finished flowering, resist the urge to cut off the green spikes. Phalaenopsis can rebloom from these, so removing them means the plant has to produce an entirely new spike from scratch — which can delay your next flowering by a year or more. Leave them alone until they've completely died back on their own.
Inspecting the Roots and Repotting
Once flowering has finished and there are no new spikes in sight, it's time to take a look at the roots. If the plant is root bound, it's time to repot. We highly recommend clear pots, as Phalaenopsis roots actually photosynthesise light — something a solid pot will interfere with. Good drainage is equally important, so make sure your pot has plenty of holes.
Go up no more than one or two pot sizes — for example, from a 50mm to a 70mm, or a 70mm to a 90mm. You want enough room for the roots to stretch out but still hug the sides of the pot. Standard clear pots, spiral pots, and basket pots all work well. Basket pots allow the roots to grow freely outside the pot, embracing the plant's epiphyte nature — but more on that later. This is a personal choice rather than a necessity.
To remove the plant, either dislodge it gently from the pot or, if it's in one of those soft clear pots, carefully cut down the centre with sharp scissors and peel it away. Remove as much of the old media from the roots as possible and dispose of it — reusing old media can reintroduce fungus and bacteria into your fresh mix. Trim any soft or rotted roots while you're at it, this won't harm the plant and actually encourages new healthy growth.
Conditioning and Fungicide Treatment
Repotting is stressful for a plant, especially one that's already been through the wringer, so it's important to condition the roots beforehand. Water thoroughly with a weak dose of Seasol or Rootzone by Growth Technology — a brand we swear by and use religiously, available at most hydroponic stores. We also strongly recommend treating with a preventative fungicide such as Rid A Rot by Sharp Shooter, Anti Rot by Yates, or our personal go-to, PureCrop1 — not the cheapest option, but worth every cent. Phalaenopsis are notoriously prone to crown and root rot, but a preventative fungicide applied every two weeks goes a long way in keeping this at bay. As orchids are classed as ornamentals, follow the ornamental guidelines on the label if specified.
Finding the Right Spot
Now that your orchid has been repotted, where you put it matters just as much as how you care for it. Phalaenopsis love a warm spot with bright filtered light and high humidity — most bathrooms tick all of these boxes, and as a bonus, you're far more likely to remember to water it when it's somewhere you visit every day. As epiphytes, humidity is crucial for these plants, with levels between 70% and 80% providing the moisture they need while reducing how often you need to water.
Getting Watering Right
Watering is where most people come unstuck, and getting it wrong in either direction — too much or too little — can cause serious problems. The good news is that Phalaenopsis actually make it fairly easy to get right, as long as you know how to read the roots. Healthy, well-hydrated roots are green. Silver roots are telling you it's time for a drink. Water thoroughly until you see that silver coating turn green — it can be stubborn to penetrate, so don't be shy with it.
In summer, particularly when temperatures are pushing into the high 30s, we recommend watering twice a week and misting daily to mimic their natural humid environment. Keep in mind that misting only temporarily boosts local humidity — it doesn't replace a proper watering. The media should stay moist, not saturated.
In winter, most Phalaenopsis slow right down and go semi-dormant, so pull back watering to once a fortnight. You can still mist daily. The key thing to watch in cooler months is stagnant water — because moisture evaporates much more slowly in the cold, leaving your orchid sitting in cold, wet media for extended periods is a fast track to rot and fungal issues. If you suspect you've overwatered, place the plant near a heater to help it dry out, or remove it from the pot entirely for 24 hours until the roots have dried out a little before repotting in fresh media.
Bringing It All Together
Caring for a Phalaenopsis is far more achievable than most people think, and hopefully this has given you the confidence to give it a go. Yes, the odds may have been stacked against your plant from the moment it left the greenhouse — but that doesn't mean it's a lost cause.
The key takeaways are simple — don't cut the spikes, repot into a clear pot with good drainage, use a preventative fungicide, and find a warm, humid spot with bright filtered light. Learning to read your roots will take the guesswork out of watering, and adjusting your routine between summer and winter will keep your plant healthy year round.
These orchids have a reputation for being difficult, but as you now know, that reputation has more to do with how they're grown and sold than with the plant itself. With a little attention and the right conditions, your Phalaenopsis won't just survive — it'll reward you with blooms again and again.