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.