Full Water Culture for Orchids: An Experiment

I’m back! I know, it’s been awhile since my last post (as usual). My orchids are still adjusting to our new apartment, and though I’ve lost a couple that were doing poorly even before our move, most of them seem to be pretty happy here. I’ve also achieved my first African violet bloom in about two years!

Lately, I’ve been attempting to revive my Mule Ear Oncidium, which I grew mounted on a slab of tree fern for years. After our move I un-mounted it from the slab, which was beginning to disintegrate, and cut off a whole hell of a lot of rotten roots. The plant has put out many new growths over the years but it has never really thrived or bloomed, and it had become clear to me that it was time for a change. I mean, look at the base of this poor thing:

Not to quote our president, but…Sad!

A reader named Lois recently commented that sometimes growing a sick orchid bare root and misting it can help, so after I cut the rotten roots off of this plant I decided to try the bare root-and-mist method. Though the orchid is in pretty dire shape, you can see in the above photo that it now has a few roots beginning to grow off of some tiny new pseudobulbs. So that’s promising! (Thanks, Lois!)

Then this week, I remembered something that a commenter on my Facebook page brought up: water culture for orchids (thanks, Teresa, for bringing it to my attention!). I started Googling and found a ton of YouTube videos on full water culture (FWC)* for orchids. Seriously, if you search “full water culture orchids” you’ll get about 32,500 results. From what I can tell, a woman named Samantha (see her feed here) has had a lot of success growing her orchids using full water culture, and she’s inspired a lot of others to do the same. She also started the Facebook group (Water Culture Orchids & General Care) that Teresa had mentioned on my page, so I joined it this week to learn more.

So, what exactly is full water culture for orchids? All it is is growing an orchid bare root in a container with a bit of water. That means you won’t use any potting medium! I know, it sounds a little crazy (honestly, my first thought was “that cannot be good for orchids”). But when you think about it, most common household orchids are epiphytes, which are plants that, in the wild, grow attached to tree trunks, logs, rocks, and other natural features. So in the wild, epiphytes grow at least somewhat if not entirely bare root. They don’t usually grow with their roots immersed in water, either, so that’s why I was a little suspicious of FWC. From what I’ve watched and read online, FWC can be good for orchids that have a poor root system by drastically increasing the humidity around the base of the plant. Maintaining a high humidity level can sometimes encourage an orchid to put out new roots (remember the sphag & bag method that I never actually had any luck with?). I can imagine that long term immersion in water might lead to root rot, but it seems like an interesting method to try on orchids that need a little healing.

Bit of a side note: there’s also a growing method called semi-water culture (SWC), which more closely mimics the way orchids grow in the wild. With SWC, you soak the orchid’s bare roots in water for two days, then let it sit bare root for five days. This method is more natural for orchids, but requires more effort on the grower’s part. SWC differs from the semi-hydroponic growing method (I know, SO MANY GROWING METHODS!), another orchid tactic I’ve tried with little success. Do you see a pattern here?  😛

Anyway! After watching a bunch of videos about growing orchids in FWC, I decided to conduct a little experiment on a few of my own orchids and see if it really works! Of course, it made sense to use the Mule Ear Oncidium as my first test subject, because its root system is currently in the toilet (not literally; then it would already be growing in FWC, haha). I washed a clear plastic hummus container and sterilized it with rubbing alcohol, then added a bit of tap water and unceremoniously plopped my horribly depressed orchid into it. Ta-da!

A couple leaves are bleached due to my putting it by a window with too much light. Oops.

One key to growing orchids in water, according to YouTube videos, is not to submerge the plant too much. With a Phalaenopsis, you should only add water to the container up to the base of the plant—you don’t want the water reaching the level of the bottom leaves. Otherwise you will likely cause the leaves to rot. It sounds like some folks have luck merely suspending their plant over a bit of water rather than allowing the roots to soak in water. Whatever you do, you want at least some of the roots to have exposure to oxygen (and air circulation, which is important for orchids no matter your growing method).

I decided to try full water culture on two other orchids that aren’t super happy right now. One of them is the Dendrobium kingianum that I bought during the Orchid Show at the New York Botanical Garden a couple years ago. This lovely orchid was doing so well for some time after I brought it home, but it has deteriorated.

Most of the roots you see were hollow and rotten.

As I found out yesterday when I unpotted it, it barely has any viable roots left. There are a few tiny new growths with some nice new roots coming out of them, so that’s good, at least.

 

This orchid definitely seems like a good candidate for a water culture revival!

The third orchid I selected for my water culture experiment is a NOID Phal that has also gone downhill over the years, though it actually has a few decent roots left:

Here’s the Phal in a glass vase with water.

A few additional details I’ve read regarding FWC maintenance:

  • •  Add water as needed to maintain the starting level.
  • •  If the water starts to get murky or green, wash the container, rise the roots, then add fresh water.
  • •  Hard water is not recommended! Soft water is better.
  • •  Fertilize lightly once or twice a week by mixing a very weak orchid food, letting the plant soak in it for 10-15 minutes, then changing out the fertilizer water with fresh water.

From what I’ve read, it can take months for an orchid to adjust to FWC and start putting out new roots, so patience is paramount. I’ve only just placed these three orchids in FWC in the past 24 hours, but I’ll update you on their progress here (also on Instagram, Facebook, and Twitter)!

*Another term for this growing method is orchid hydroponics.

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