Has your phalaenopsis apparently stopped growing? Are its leaves drooping? I hope my advice will help you. For some 20 years, in my home, in Milwaukee, Wisconsin, I have been growing phalaenopsis.
Could sucking insects be feeding on the leaves? Check this by using a jewelers loupe to inspect the top and particularly the underside of the leaves. If you see “critters” then check the American Orchid Society’s advice.
If you are new to phalaenopsis, the most likely cause for drooping is under hydration. Remove your orchid from its container and inspect its roots. If they’re firm, then you’ve likely been under watering. If they’re mushy then you’ve either been watering your orchid too frequently or you’ve kept it in too big a container.
Inspect and Possibly Repot
I remove mushy roots with a pruner that I’ve either heated with a flame or on which I’ve sprayed 91% isopropyl alcohol. I do this to control possible plant viruses.
After pruning, I repot the phalaenopsis in a clear-plastic container. Most of my containers are repurposed for which I have fashioned drainage holes on their bottoms and ventilation holes on their sides. To do this, I use a rotary tool and cutting blades. But for less money and probably with greater safety you can form holes by melting the plastic with an inexpensive soldiering iron. Do check out “My Cheap Orchid Pots.”
Container size and ventilation are very important. You want your orchid to cycle through wet, and nearly dry phases. I’ve found that phalaenopsis grow best when their container somewhat confines their roots. Just check the young plants from professional nurseries which arrive with their roots well filling their containers.
If your orchids roots are sprawling then imagine them balled up. You can render deep containers functionally shallower by placing pieces of Styrofoam, an inverted plastic cup (requires space but does not store water), or small rocks at the container’s bottom. By the way, the rocks enhance the container’s stability.
I keep my phalaenopsis in either fresh (but not fine) fir bark, sphagnum moss, or a mixture of the two. Importantly, I make sure the juncture of the lowest leaf with the orchid’s body is at least 1/4 inch above the medium’s surface. This way water will not collect between the leaf and the orchid’s body if you water carefully!
By the way, these days, in the US, Lowe’s charges about $8 for 8 quarts of “Better-Gro Special Orchid Mix.” I’ve also found “Better-Gro Premium Grade Orchid Moss” to work well. Note that I don’t work for Better-Gro.
Below, I describe how you can use heat to stimulate root growth., But if you don’t have the resources to add heat then a repot can be sufficient. This is particularly true if you keep your orchid in a humid environment. Nevertheless, after say six or eight weeks, if your your orchid does not look better than remove it and inspect its roots. If roots are growing but some are rotting then perhaps you should have used a smaller container or have added more ventilation holes to shorten the wet phase. With experience you will come to best estimate appropriate container size.
Stimulating Growth with Heat
The key for promoting growth is heat. I place the container on a heat mat. Currently, I use an inexpensive AC Infinity SUNCORE A5, Waterproof Seedling Heat Mat. They’re available in various sizes. To adjust the heat level, I keep a thermometer on the mat and set the control to achieve a temperature between 80 and 85 degrees Fahrenheit.
To make sure the roots warm up, I capture the heat rising from the mat by placing the container in a heat trap. If you don’t do this then the plant does not well warm during winter here in Milwaukee.
Above you can see a phalaenopsis resting in moss, in a clear plastic container. (For illustrative purposes, the container is set on an angle.) Supporting the container is an inverted green container whose bottom was removed and whose holes had been covered with duct tape. This inverted container is the heat trap. The trap is resting on a gray heating mat.
I’ve also made heat traps by removing the bottom of plastic containers salvaged from recycling bins. Ideally when inverted the diameter of the trap’s bottom should be greater than the diameter of the orchid pot’s bottom. Also, when inverted the diameter of the trap’s top should be about the diameter of the orchid container’s top. With these dimensions the trap well captures heat and is removable.
Before moving on it, note well, that it is possible to provide too much heat. This has happened to me while using a shallow plastic container. I had followed the instructions above but had kept the heat at 100 degrees Fahrenheit. After about a month on the mat I did not see any new growth. So I checked the roots and discovered that the bottom-most roots were dead. The high temperature had worked in the past, but in the past the container’s bottom had not trapped as much heat as did these shallow containers. Given this lesson, the most cautious approach is to place a thermometer on the mat and verify that the temperature is between 80 and 85 degrees Fahrenheit. (You could place the thermometer in the container but I’ve had success by just setting the thermometer on the mat.)
When to Water
Orchids with roots adapted to growing in water or light expanded clay aggregate (LECA) can certainly thrive. That said, I rarely grow orchids in water or LECA. Instead, I use media such as fir bark, sphagnum moss, coco coir, or perlite.
To assess whether my phalaenopsis needs watering, I always keep a wooden skewer poked deep into the center of the medium. From time to time, I withdraw this “dipstick” to assess moisture level. If the skewer’s end is approaching dryness, as revealed by placing the end on my upper lip, then most likely my phalaenopsis needs water.
Another clue is available if you keep your orchids in transparent containers. Inspect the roots. Dry roots are gray; moist roots are green. Of course, visual inspection cannot reveal the moisture level in the container’s center as can the wooden skewer!
If you are ever in doubt about watering, don’t water! Phalaenopsis kept soaking wet for several weeks (planted in bark, moss, etc.) will likely not recover; their roots will rot! But phalaenopsis not watered for several weeks will recover!
How I Water and Fertilize My Phalaenopsis
I use two watering containers because I water my orchids twice. First, I very thoroughly water the medium with tap or rain water, at room temperature, to wash away salt accumulations. I am very careful to not water the orchid’s crown to avoid promoting a fungal infection. If water enters the crown I use a napkin to absorb the water, a small fan to evaporate the water, or my breath to blow the water away.
Immediately after the initial watering, I water again using tap water because it contains beneficial minerals. To the water I have added fertilizer that has been diluted to about 1/4 the recommended level.
Which fertilizer to use? They all seem to work, even inexpensive Stern’s Miracle Grow with an analysis whose nitrogen-phosphorus-potassium designation is 24-8-16. Often recommended are fertilizers with balanced designations such as 10-10-10 or 20-20-20.
More Information
You can find valuable information about caring for phalaenopsis and other orchid species at the websites of the American Orchid Society, the St. Augustine Orchid Society, and if you live in the Midwest The Orchid Growers Guild.
Carefully read the advice regarding when to water for over watering or over potting orchids is the most frequent mistake of folks who have just fallen in love with growing orchids!
Please let me know how this page worked for you.
–Marshall Lev Dermer
Send mail to: marshall@dermer.com
1/20/2025