NOTE: I recommend reading my updated post about how to fertilize orchids.
Like all living things, orchids need nutrition. Feeding (fertilizing) your orchid is an important part of caring for it and making sure that it lives a long and healthy life. This post about how to fertilize an orchid is waaaaayyy overdue…but better late than never, right? I’m going to talk specifically about fertilizing Phalaenopsis (moth) orchids because Phals are the most common orchids for beginners, available everywhere from corner delis to Home Depot, Ikea, and Trader Joe’s.
How Orchids Grow in the Wild
Before I get into the actual process of how to fertilize your orchid (which is actually not difficult), it’s important to understand how Phalaenopsis orchids grow in the wild. Phals are epiphytes, which essentially means they are air plants—they grow off of tree trunks, branches, rocks, and other items in nature. Their roots are mostly, if not entirely, exposed to the air; Phals do not grow up out of the soil like a typical terrestrial plant. The roots collect moisture and nutrients from the surrounding environment; basically, organic materials like rotten leaves, bird droppings, and minerals in rainwater serve as orchid food.
A Basic Discussion of Orchids’ Chemical Needs
I’m still very new to this stuff, so trying to explain it in understandable terms is a great exercise for me! Bear with me here. Okay, so the three most important nutrients for orchids are nitrogen (N)*, phosphorus (P), and potassium (K). Each of these elements is responsible for a different aspect of the orchid’s growth:
- N: Leaf and stem growth
- P: Root growth and flower production
- K: Overall health and growth
When you are looking to purchase an orchid fertilizer, you’ll want to check out the ratio printed on the label. You’ll see something like “30-10-10” or “20-20-20.” This ratio refers to the percentage of N-P-K in the fertilizer. When selecting your fertilizer, the simplest guideline is to use a higher nitrogen proportion (30-10-10) for Phals planted in bark, and a balanced proportion (20-20-20) for those planted in other types of potting medium. Why the higher nitrogen for bark mix? Over time bark starts to break down, and in the process of breaking down it uses up lots of nitrogen—leaving less for the plant to absorb. Orchid geeks more knowledgeable than myself could explain which types of fertilizer are recommended for use during each season, but I’m not there just yet. And I’m not even getting into a discussion of how to feed orchid species other than Phalaenopsis…I’m sticking with the basics here.
When and How to Fertilize Phalaenopsis Orchids
Now we’re ready to talk about when and how to feed your orchid. There are two suggested fertilizing schedules. You can take your pick:
- Once per month—feed orchid with full strength fertilizer (follow the directions exactly on the package)
- “Weakly, weekly”—feed orchid with a weaker strength fertilizer than what’s recommended on the package. One-quarter strength is a good rule to follow.
And now we’ve arrived at what you’ve been waiting for…instructions on HOW to fertilize a Phalaenopsis orchid. Follow these easy steps:
- Mix your fertilizer according to the directions on the package in a concentration based on which of the two above feeding schedules you’ve chosen.
- Before you apply any of the fertilizer, water your orchid THOROUGHLY. When dry roots are exposed to fertilizer they can burn and become damaged, so you want to make sure the roots are wet before you feed the plant.
- Pour the fertilizer mixture into the pot and let drain as per usual.
That’s it! Just make sure not to overfertilize, because doing so can stunt your orchid’s growth. Either stick with a lower concentration of fertilizer or only feed once a month.
Some Good Fertilizer Brands**
- Grow More: this brand offers a number of different proportions; I’m currently using their 20-10-20 (greenish-aqua) concentration, seen to the right.
- MSU Feed Me!: Available at Repotme.com, this fertilizer was developed at Michigan State University and is often recommended by orchid growers over at orchidboard.com. I haven’t personally used it yet but would like to give it a try.
- Dyna-Gro Orchid Pro: Another recommendation from the smart folks at orchidboard.com that I have yet to try.
As I mentioned, I’m still very much in the process of learning how to care for orchids. My own collection is doing quite well overall but I’m sure there are things I could be doing better. If you have any advice about orchid fertilizing for people new to growing these lovely plants, I’d love to hear your comments below!
*Nitrogen can either be derived from urea, ammonia, or nitrates. In natural settings, nitrogen derived from urea is not readily available to orchids, so you need to look for a “urea free” fertilizer.
** I’m solely listing these brands because I’ve either used them or have read that they are good for orchids. I have never received any free samples or products from any of these brands. Just want to be clear that I’m not shilling for anyone.
I prefer the weakly weekly method. I also flush with plain water once every 4 – 6 weeks. Don’t want salt build up. 🙂
That’s a good point, Bob. Thanks for the tip!
Good advice. Have been doing weakly weekly and water with plain water before applying fertilizer. Wondering about putting the fertilizer mix in the spray bottle to use on roots in between watering.
Probably not great to spray the roots with fertilizer in between watering, unless you wet them with plain water first. Otherwise you could damage them.
Many thanks for this article – I’ve been scratching my head lately – trying to figure out what fertilizer to use for my orchid!
You’re welcome — thanks for reading!
This is very useful ! I usually fertilize my phalaenopsis orchids once at every two weeks.
THANK YOU! I was watering my orchid everyday. Now I know why it was dying.
Hi, I am new to taking care of Orchids, Your blog is really good, I have done a lot of research and your blog is very detailed, I did not even think about watering the roots with plain water first, Great Tip Thanks:) I received a beautiful basket from my husband on our anniversary, it had the most beautiful Orchid and I killed It in 2 weeks, It was expensive, so I was very upset, I wish I knew then what I know now! Thanks again for your great blog, I look forward to reading more about what you have to say about Orchids.
Thanks for your comment and for reading!
I have 2 questions.
After I cut my Orchids Stem from one node above the base( because It was growing a new leaf and I was told to cut it from there), one big leaf has started to become soft and darker. now almost all of the leaf surface is dark green and soft. What do you think the reason could be?
My other question is, How can I breed/reproduce/pollinate(I don’t know which word is the right one!) my orchid?
thanks in advance
Hi Ria, is the big leaf wrinkly as well as soft? It might be due to dehydration. It could also be that the orchid’s root system is not healthy. You might want to take the plant out of the pot, take a look at its roots, and trim away any dead or rotting roots.
With regard to reproduction, it’s very hard to do this at home — especially if you’re talking about actually pollinating and then growing new orchids from seeds, because they need a sterile environment. However, you could try some Keiki Grow Paste, which I’ve experimented with. This sometimes results in a baby plant growing off of the mother plant, which can eventually be removed and potted on its own. Check out my posts about growing keikis:
when my phalaenopsis is finished blooming do i cut that stem back and if so how far back do i cut it , , how big of a pot do i put it in when i repot this plant. do the roots need to be bound
thank you [email protected]
Hi Flora, thanks for your questions. I’ve written a blog post about how to cut a Phalaenopsis orchid spike, which you can take a look at here: http://bklynorchids.com/2012/04/06/how-to-cut-a-phalaenopsis-orchid-spike/
If the root system is completely taking over your orchid’s current pot, then it’d be good to move your orchid into a pot 1 or 2 inches bigger, depending on just how large the root system has become. If there’s still plenty of room for potting medium in the current pot, I’d say leave it there for now. Happy growing!
Thank you for the information on cutting and fertelizeing the plant i will give it a try
I have my phals potted in bark, and I understood that for this medium the best fertilizer would be a 30-10-10 one. In my region I didn’t find such a fertilizer, but I know a person which makes custom fertilizers.
My question would be: For this fertilizer ratio, can you please tell me what should be the amount of fertilizer to be used? The fertilizer is liquid.
Are there any phal growers that are using Grow More 30-10-10 or Miracle Grow 30-10-10? Can you please tell me how much fertilizer says the producer that has to be used?
Thank you a lot!!
After 5-1/2 years of almost continuous blooming with nothing but weekly watering–no fertilizing–my phael was looking a bit peaked, so I raced for the internet to find a fertilizer suggestion. Clearly I’ve been starving the poor baby. Worse, she’s been in a solid pot–no drainage. Still she blooms. She does love the light she’s exposed to, but I’m beginning to think I’ve got a miracle on my hands. I’m awed and grateful, because she has chosen to continue to give me incredible joy and patience for so long. On my way to the nursery to find a great fertilizer. . .thanks, folks!
Hi there and thanks for your comment. That really does sound like a miracle orchid! Fertilizer should help keep her going for a nice long life. I would definitely recommend repotting the orchid into a pot with drainage holes, though. No drainage allows water to stand in the bottom of the pot, which can lead to root rot. Happy growing!
Thank you for your posts. I would like to know if it is OK or even advisable to fertilize at repotting or is it better not to and wait some time? How long?
Hi Virginia, You can fertilize when you repot, but just make sure you only do so when the roots and potting medium is already wet. You don’t want to burn the roots!
what can I do????my phal is dying, I take out my phal to cheke and the root looked so bad, and cut a lot bad root (brown color), I need to know what fertilizer is good to make grow up the roots again, where can I get? I mean what store? thank you
sorry, I forget to say I live in philadelphia, PA..thank you again
I got my 1st phalanx Fm my son 1.5yrs ago. Grows plenty of leaves & roots, but no stem. I have never fertilized! It came in a pot with no drainage holes. I water about once every 7-10 days. I want to mount on wood, but have no idea how or when. I live in SW Missouri & my window faces north. I have a grow lite suspended above plants on a timer. They get lite Fm 5:30am till 8pm. Got my 2nd phalanx a month ago, in bloom. It has 4 flowering stems. Pot is clear w/drainage holes & doesn’t appear to need reporting yet. My question is how to transfer a potted phal to wood, & when is the best time. Thc for your site – it’s extremely helpful!
I’m very new to the world or orchids and fertilizing in general, so I have a question. I’m going to try using the Grow More fertilizer and it calls for 1 tsp of fertilizer per gallon of water. Now, I’d like to try the weakly, weekly schedule, so that would make it 1/4 tsp of fertilizer per gallon of water. My question is, after I mix the 1/4 tsp in a gallon of water, I’m supposed to give that entire gallon of water to my one orchid each week? Or should I be giving only a part of that gallon? A gallon of water every week seems like a lot…
Hi there and good question! You don’t need to use the entire gallon to water your orchid; just use as much as you need to thoroughly drench the potting medium. When the water begins to run out through the drainage holes as fast as your pour the water in, you’re all set. Remember to use plain (not fertilized) water on your plant before pouring fertilizer into the pot, because fertilizer on dry roots can damage the plant. Happy growing!
Nitrogen (N): For green leafy growth
Phosphorus (P): For healthy root and shoot growth
Potassium (K): For flowering, fruiting and general hardiness
This differs slightly from the definition above, is this correct ?
If so, what should the N-P-K vlaues be for Orchid Fertiliser ?
I would like to know about fertilizing orchid especially phlaenpsis
Hi Sarah. love your site – so informative. just wanted to chime in since you mentioned a couple good options or orchid feeding. I subscribe to the weekly weakly feeding as well and found an organic product has really helped my orchids! this website https://earthwormtechnologies.com creates all-purpose plant food. I first bought some for my houseplant but tried their teadrops on my year and this year and they did really well. I make a bowl of water with the packet and then sit all my orchid pots in it, then let the water drain out. they seem s to love it, thought you might want to chec it out – especially since I personally hate high npk fertilizers (iv’e killed many orchids that way before) 🙂
I water my orchids with water filtered through a Brita filter with good results. My Question is, if I rinse my roots with tap water will the chlorine in the tap water hurt my plants. I am on a city water system. Thanks.
According to the American Orchid Society, chlorinated tap water can be used to water orchids. If you’re concerned about it, though, you can fill a bucket of water and let it sit uncovered for 24 hours before using it on your orchids. Letting the water sit uncovered allows some of the chlorine to evaporate. This link has some more detail: http://www.aos.org/orchids/orchid-pests-diseases/fertilizer-burn.aspx
I hope that helps!
I have yellow spots developing on the leaves of my orchids. I water with three ice cubes once a week. I fertilize once a month with Dyna-gro Orchid-pro, 7-8-6. Ant ideas what’s causing this ? They don’t get as much light as they should , but they are in a very bright sun room .
Hi Steve, I’m not sure what yellow spots might mean, but I don’t recommend the ice cube method of watering. Please check out my post on how to water orchids here: http://bklynorchids.com/2010/03/12/how-to-water-a-phalaenopsis-orchid/
Are you using full strength fertilizer once a month? If so, you might want to switch to the “weekly, weakly” fertilizing schedule that I’ve outlined here and see if that has any effect.
I hope that helps!