I have had a number of phalaenopsis orchids with good roots but eventually the plants had stopped growing and their leaves had become limp.
Warming Up Your Phalaenopsis
After pruning away dead roots, I repot the phalaenopsis in a clear plastic pot with good drainage, air holes on the pot’s side, and either fresh (coarse) fir bark or fresh sphagnum moss. Then, and this is the key, I place the pot on a heating pad set to 100 degrees Fahrenheit. (I have been using K&H heating pads for dogs, the one’s encased in hard, ABS plastic. By the way, I often keep rocks at the bottom of pots to promote pot stability and store heat.)
To make sure the roots warm up, I capture the heat rising from the pad by placing the orchid pot in a heat trap. If you don’t do this then the plant does not well warm during winter here in Milwaukee, Wisconsin.
Above you can see a phalaenopsis resting in moss, in a clear plastic pot. (For illustrative purposes, the pot is resting on an angle.) Supporting the pot is an inverted green pot whose bottom was removed and whose holes had been covered with duct tape. This inverted pot is the heat trap. The trap is resting on the gray heating pad.
I have 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 pot’s top. With these dimensions the trap well captures heat and is removable.
When to Water Your Phalaenopsis
Orchids with roots adapted to growing in water or light expanded clay aggregate (LECA) can 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. With roots adapted to these media, beginners most likely kill their orchids by watering too frequently and so keeping roots wet for too long.
If you are ever in doubt about watering, don’t water! Phalaenopsis kept in water for several weeks (along with bark, moss, etc.) will likely not recover; their roots will rot! But phalaenopsis not watered for several weeks will recover!
To assess whether my phalaenopsis needs watering, I always keep a wooden skewer deep in the center of the medium. From time to time, I withdraw this “dipstick” to assess the moisture level. If the tip of the stick is approaching dryness, as revealed by placing the tip of the stick on my upper lip, then most likely my orchid needs water.
Another clue is available if you keep your orchids in translucent pots. Inspect the roots. Dry roots are gray; moist roots are green. Of course, visual inspection cannot reveal the moisture level in the pot’s center as does the wooden skewer.
Watering and Fertilizing Your Phalaenopsis
I use two watering containers because I water my orchids twice. Initially, 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 deadly fungal infection! If water enters the crown I use a napkin to absorb the water or a small fan to evaporate the water.
Immediately after the initial watering, I water again using tap water because it contains important minerals. To the water I have added fertilizer that has been diluted to 1/4 the recommended level.
Which fertilizer to use? They all seem to work, even inexpensive Stern’s Miracle Grow. If you don’t want to use an inexpensive fertilizer there are special ones for orchids with balanced formulations like 10-10-10 or 20-20-20.
You can find valuable information about caring for phalaenopsis and other orchid species at the websites of the American Orchid Society and the St. Augustine Orchid Society. Carefully read the advice regarding when to water for over watering or over potting orchids is the most frequent mistake of beginners!
Let me know how this works for you.
–Marshall Lev Dermer
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