Phalaenopsis are among the most popular orchids in the trade, loved for their ability to flower under artificial conditions, and their ease of care.
Species of this genus are epiphytic : they usually grow anchored to other plants and absorb their water and nutrients from the rain and humidity. They're not to be confused with terrestrial orchids from temperate regions, those grow in open soil.
Common name : Moth orchid
Scientific name : Phalaenopsis
Family : Orchidaceae
Category : Indoor
Type of plant : Perennial
This description is for indoor orchids, especially moth orchids, that are the easiest to grow and the most common. If your orchid is rare, you might need to follow instructions from the reseller. That being said, moth orchids aren't very difficult to grow : just a bit of light, the right temperature, some humidity, and love.
In the wild, Phalaenopsis species are typically fond of warm temperatures, thriving in temperatures around 20 to 35 °C (68–95 °F). They adapt well to conditions more comfortable for human habitation in temperate zones (15 to 30 °C or 59 to 86 °F), though at temperatures below 18 °C (64.4 °F) overwatering might cause root rot. Phalaenopsis requires high humidity (60–70%) and low light of 12,000 to 20,000 lux, but can adapt to the lower humidity found in our homes.
Did you know? Studies have shown that daytime temperatures declining below 27 °C (81 °F) initiate flowering, while temperatures above 29 °C (84 °F) inhibit it.
Orchids form a large family of monocotyledon plants. It's one of the most diverse plant families, counting more than 25,000 species, spread among 850 genera.
With neither pseudobulbs nor rhizome, Phalaenopsis show what is called a monopodial growth habit: a single growing stem produces generally two thick, fleshy, alternate leaves a year from the top, while the older, basal (at the base) leaves drop off at the same rate. A very healthy Phalaenopsis can have up to ten leaves. The inflorescence, either a raceme or panicle, appears from the stem between the leaves, and bloom for several weeks, after which the plant will need to regain energy for further leaf, bud and root development.
Plant my moth orchid
Plant your orchid in a medium prepared for moth orchids : 5 parts fresh fir bark, 1 part horticultural charcoal and 1 part sponge rock such as perlite. Avoid using garden mulch in lieu of fir bark, or charcoal for barbecue instead of horticultural charcoal. Orchids are more likely to flower well if kept moderately pot-bound : choose a container which will just accommodate the root system, with sufficient drainage holes. To finish off, water your orchid thoroughly, by simply soaking the plant in a bucket of tepid water for an hour or so, then allow it to drain completely.
Water my moth orchid
Moth orchids dislike overwatering, and they loathe hard water even more. if your tap water is hard and you can't use rain water you can always rely on distilled water, but keep in mind that distilled water - and to a lesser extent rain water - lack some of the minerals that orchids need, so you might need to supplement with fertilizers a little more often. Use room temperature water, in the mornings, to allow the pot to dry all day. Always let the water drain through, because the roots of your orchid won’t like to sit in water. Remember they are epiphytes and as such they grow on other plants, not in soil, so most of their water needs are actually fulfilled by the humidity in the tropical air.
How much should you water? Don’t splash in a bit of water every other day – on the contrary, water your Phalaenopsis thoroughly when you do. If your orchid has gone bone dry, you can even soak it for 10 minutes.
How often? Every week or so from spring to autumn. In the winter the routine should drop to watering every 15 days. Of course, the humidity in your home makes a difference, and whether your beloved orchid is in bark or moss too. You might need to water more often in bark than in moss - as moss holds moisture and bark doesn't.
Fertilize my moth orchid
From March to October, add special liquid orchid fertilizer twice a month.
Repot my moth orchid
When should you repot your moth orchid? Easy : either when the lower leaves die and the stem goes weak, or when the chunks of bark in the potting mix have decomposed, becoming too fine and soil-like. A good rule of thumb is to repot plants every two years after flowering when new growth appears, spring through fall. In any case, never repot orchids that are in bloom or they will lose their flowers.
What medium should you use? The perfect mix is 5 parts fresh fir bark, medium grade, from ¼ to ½ inch chunks - and not garden mulch! - 1 part horticultural charcoal (and not BBQ charcoal) and 1 part sponge rock such as perlite. Remember, better done than perfect : if you can’t make it perfect just do your best. Quick note : the charcoal is quite important, especially if you use fertilizer as it will neutralize fertilizer salts.
What pot? Most orchids are more likely to flower well if kept moderately pot-bound. Choose a container which will just accommodate the root system, and if the pot is too large for the plant, the roots might rot because the excess medium retains too much water for them. Oh, of course, choose a pot with sufficient drainage holes. Plastic or clay is up to you - but we prefer clay because your orchid might need the weight of clay to prevent toppling and also because clay allows more air into the root area, preventing root rot.
Now, how? Just grasp the plant by the stem and gently work it out of the pot. Remove as much of the old potting medium as you can. Gently peel off dead or dying leaves, and any dead tissue on the stem left behind after you removed the leaves. Using a sharp and clean razor blade, cut off any dead tissue from the roots. If in doubt, gently squeeze the roots : dead tissue is hollow when squeezed or looks wiry, while live tissue is solid. When you’re happy with it, proceed with the repotting itself : gently place the roots in the pot and slide them down until the base of the bottom leaf is slightly above the rim of the pot. Push potting medium into the air spaces around the roots, making sure not to leave any air pockets, until the level of the potting medium is just below the base of the lower leaves, and press gently. Breathe, we’re almost there.
Wait, it’s not finished? Now you just need to water your orchid thoroughly. Simply soak the plant, pot and all, in a bucket of tepid water for an hour or so, then let it dry thoroughly, allowing it to drain completely. One last thing : discard any water left in the drip pan. You did a fantastic job.
Check on my moth orchid
Watch out for spider mites, aphids and scale insects!
First, those infamous spiders! They're actually not spiders, but a type of mite. They suck the sap, causing the leaves to turn a marbled yellow-white-silver, and the mites sometimes spin tiny webs. These mites mainly attack the back of the leaves : moisten a cotton pad and swab underneath the leaves — if you notice tiny little red marks, someone's home. To get rid of them, here's a simple trick: these spiders hate water! Spray a fine mist of water on your leaves to get rid of them. You can add dish soap, vegetable oil, o rubbing alcohol into the water for extra effect. If you have more than one plants, isolate any web-infested plant, as spider mites breed quickly from pot to pot.
For aphids and scale insects, it's a little easier as those are usually detectable with the naked eye. Should you spot an aphid - recognizable by its pear-shaped body - or scale insects, spraying the soap and water should take care of the problem if the infestation is relatively new. If the insects have established their headquarters on your beloved orchid, the next level of treatment is probably a chemical insecticide.
As a general rule, you should always check your orchid regularly for signs of infestation and remove potential problems as quickly as possible : the sooner the better. Also, most infestations spread from one plant to the other : always give extra attention when introducing a new plant in your collection. And the final word is : don't give up. If you are battling an infestation, repeat treatments every ten days or so : persistance is the key.