Phrag. Growing Medium?

[e-spice]

Hi,

For 20+ years I've grown phrags very well in LECA and semi-hydro (S/H) culture. Now though, getting good quality LECA seems impossible. The previous brand I used, Hydrofarm's Grow!t, has changed to a junk source to save a penny or two a bag and I can't find any of the old product anywhere. Seems like to some degree it has always been difficult to find good LECA and it is always expensive.

I know most people are accustomed to growing in bark. I'm toying with trying that out but am just so used to S/H culture. Just curious, what do you grow your phrags in?

Thanks for any input.

 

[mrhappyrotter]

I grow and have grown a lot of Phrags in a rockwool based media for over 20 years now (though don't quote me on the exact start of my rockwool experiment). I tend to add additional "stuff" to it, like LECA or slate chunks, large grades of perlite, small chunks of lava rock, and sometimes I even mix in organic components. It hardly seems to matter what I combine with it. I have less luck with 100% rockwool, but many folks grow Phrags in pure rockwool with nothing else mixed in.

Rockwool has an additional advantage if you have to have it shipped (which I do), it's lightweight so shipping charges are generally a bit less.

You will need to rinse and soak it outdoors or in a well ventilated area. Many resources suggest that you need to pre-treat it to stabilize the pH and add some nutrients, though I haven't seen a huge difference either way as long as I rinse it well and soak it before use.

Of course, bark based mixes work well, too. Most Phrags are not terribly picky about the media, at least by orchid standards.

Another option is to switch to a cocopeat based media. Cocopeat typically gets sold as dry bricks that you soak and rehydrate for use. It's widely available -- you can order it online and many pet/department stores carry it because its a common thing to use for reptile enclosures. It also requires some rinsing & soaking before using it for plants, and you really need to use an EC/TDS meter to test it first since sometimes the stuff can be full of salts/minerals which must be leached out first. You might consider adding some perlite or other chunky, inert additives to it for additional air capacity, but similar to rockwool, some growers use 100% cocopeat for Phrags and other orchids (even epiphytic orchids like Phals).

Coconut husk chunks are another option, which I use and have used from time to time. The issue I have with that stuff is similar to the issue you had with LECA, the quality of what's available is highly variable. One time you get really good stuff, next it's total crap. Another concern I had is that a lot of my Phrags did really well in it initially, but over time they appeared to develop some nutrient related issues. Coconut husk doesn't break down quickly, so you might think to avoid repotting yearly/regularly, but perhaps that is what's needed to overcome the nutrient issues?

Good luck!

 

[Heather]

I’m experimenting! I have my kovachii hybrids in rockwool/ chunky perlite mix. Mostly because the first one came in that from Orchids Ltd. I have limited humidity and a warmish growing area and I find it keeps the roots cooler. I have several besseae hybrids in bark mix (fine bark, charcoal, perlite) and I’m now adding a little of the rockwool cubes to that. It’s great to put over a new root and they are excellent to strategically insulate new stolons on my mexipediums.

I recently got a second Fritz Schomburg in bark and decided to keep it in that to compare to my older one in rockwool. Will see if either makes a difference.

 

[big923cattleya]

This is an image of my general orchid media mix. I use this for everything!
If I am growing small besseae type Phrags, I use the smaller elements of my mix selecting seedling bark, seedling orchiata, charcoal and perlite. If I want them to grow wetter, I increase my water frequency OR I could add a little chopped up sphagnum.
When I am potting a kovachii hybrid or something larger like a Sorcerer’s Apprentice, I grab handfuls of my mix that favor medium bark, Leca pellets, charcoal and perlite. I generally water them a little less frequent.

If I have a bunch of kovachii type things to repot, I’ll add more Leca and medium bark as I begin knowing it is going to be more of a temporary thing.
This container is like 4” deep x 10” wide by 16” long. It has a snap on lid. I use it both inside or out depending upon season.
Like I said, I use this for Cattleyas, Oncidiums, Phalaenopsis and more recently Zygopetalum intergenerics. Their mix might be 33-50% chopped sphagnum. I have been growing those four 4 months and they are growing like weeds!!!

 

[Ray]

Most of my phrags are still in S/H culture, although following Tony’s lead, have begun experimenting with rockwool cubes and LECA, rockwool and perlite, and all three.

There is no treatment that will have a lasting effect that “changes” the properties of the glass…

 

[terryros]

I’m experimenting! I have my kovachii hybrids in rockwool/ chunky perlite mix. Mostly because the first one came in that from Orchids Ltd. I have limited humidity and a warmish growing area and I find it keeps the roots cooler. I have several besseae hybrids in bark mix (fine bark, charcoal, perlite) and I’m now adding a little of the rockwool cubes to that. It’s great to put over a new root and they are excellent to strategically insulate new stolons on my mexipediums.

I recently got a second Fritz Schomburg in bark and decided to keep it in that to compare to my older one in rockwool. Will see if either makes a difference

I used a combination of LECA and rockwool for my Phrags and they grew acceptably, but they really facilitate cyanobacteria growth on the top layer and I think they compact and eventually reduce air space in the pot. I can’t immediately give you the source, but I think Orchids Limited has stopped using rockwool in their potting mixes. I am using LECA only with my Phrags and Paphs and I just adjust my watering to achieve the correct degree of moisture for the plants.

 

[BrucherT]

Well that’s that for me with LECA. How does anyone know if they have “good” LECA or “crap” LECA? It all looks the same. I can tell with bark at a glance.

 

[dmcmkl]

Orchids Ltd has for the most part stopped using rockwool for their phrags. Jason feels that rockwool stays too wet and this leads to it harboring more pathogens. I have found the same thing with my phrags. The grow pretty well for a couple of years and then start to decline. Root growth seems to be the problem. Old roots rotting with no new roots taking their place. I'm in the process of moving all of my phrags to semi hydro in LECA.

Of course as has been stated many times here on the forum everyone's growing conditions are different. What works for one person doesn't necessarily work for another.

 

[monocotman]

I’ve found the same thing with my more mature phrags. A decline in root growth. I just end up with a few surface roots. The only way I’ve found to use rockwool well is the tray method where the plants sit in a just an inch or so of wool with a covering of moss. It’s working well so far with the seedlings .

 

[big923cattleya]

Well I agree, you can pretty much look at bark and know right away if it is good or bad! I avoid bad sources or vendors.
I do not rely on Leca as the dominant part of my media. There by Leca can’t be good or bad. It plays a minor role in my mix. I know I have seen perfectly round little baked pellets or “beads” and some that are imperfect with pock marks or uneven surface to the individual pellets let’s say. But again, if it is 10-20% of my mix, it does not need to be perfect.

And I don’t use rock wool because when I first encountered it maybe 30 or so years ago, it always seemed to hold too much moisture under my conditions. Nowadays my media components leave me happy. I admit that a vendor of Phrags that I buy from on line uses it a lot. Things do arrive “quite damp”. But I don’t leave ANY NEW ARRIVAL in its media for very long.
I developed perhaps a nasty habit years ago!
A. I wanted simplicity and consistency in my media. An unobtainable dream? No, not really. But I did try to simplify as much as I could.
B. I adopted a universal policy of repotting all new arrivals ASAP. Why? To inspect the roots to see what was happening there. It avoids ‘surprises’ down the road. I had an idea to get them into my mix as quickly as I could. That gets me to consistency quicker.

When you inspect roots during repotting early on, you quickly learn who is, or is not, a reputable vendor!
But still the bottom line is, there is more then one way to skin a cat, or more appropriately to grow a Catt!!!!
( or any orchid) stick with what works for you.

 

[terryros]

Well that’s that for me with LECA. How does anyone know if they have “good” LECA or “crap” LECA? It all looks the same. I can tell with bark at a glance.

Hydroton is what is easiest for me to obtain and Ray has studied it and it has the correct properties. I believe the real Hydroton is made in Germany.

 

[terryros]

Orchids Ltd has for the most part stopped using rockwool for their phrags. Jason feels that rockwool stays too wet and this leads to it harboring more pathogens. I have found the same thing with my phrags. The grow pretty well for a couple of years and then start to decline. Root growth seems to be the problem. Old roots rotting with no new roots taking their place. I'm in the process of moving all of my phrags to semi hydro in LECA.

Of course as has been stated many times here on the forum everyone's growing conditions are different. What works for one person doesn't necessarily work for another.

I agree with you. The key thing is getting the right balance or air, moisture, and nutrition to the roots. Watering practices are key and they differ depending on the rest of our lives. FirstRay once said that you could grow in marbles but you would have to water frequently. Round size gives optimum aeration to the root zone. Hydroton is roughly, but not completely, round. It retains more moisture for a short while than marbles, but it still dries out over a few days.

 

[big923cattleya]

Out here in Michigan with weed being legal, numerous businesses have sprung up selling grow supplies. I am told many carry different grades of perlite and hydroton/Leca.

 

[terryros]

Out here in Michigan with weed being legal, numerous businesses have sprung up selling grow supplies. I am told many carry different grades of perlite and hydroton/Leca.

I guess there could be counterfeit Hydroton, but as a trade name, Hydroton should mean the real thing. I get mine from a local hydroponics store and it is labeled Hydroton original expanded clay aggregates, Mother Earth, and Made in Germany.

 

[Heather]

Interesting. I’ve been nervous about the rockwool from the start. It’s really dry here. So far so good, been using Kelpak pretty regularly and have good roots but will remember all this going forward.

The hydro stores near me only carry the 1”cubes.

 

[terryros]

Interesting. I’ve been nervous about the rockwool from the start. It’s really dry here. So far so good, been using Kelpak pretty regularly and have good roots but will remember all this going forward.

The hydro stores near me only carry the 1”cubes.

I think the problem comes as the cubes start to compact. This happens over some months. That’s when air flow in the root zone starts to be restricted.

 

[Ray]

I think the problem comes as the cubes start to compact. This happens over some months. That’s when air flow in the root zone starts to be restricted.

That's why you add a second phase! I treat rockwool cubes as a "known pocket of water", so add LECA or LECA and perlite to ensure air between them. The rockwool fibers are small enough that they are fully saturated right from the start.

 

[terryros]

That's why you add a second phase! I treat rockwool cubes as a "known pocket of water", so add LECA or LECA and perlite to ensure air between them. The rockwool fibers are small enough that they are fully saturated right from the start.

Since I have the ability to fertigate frequently and mist almost every day, I decided that I liked pure LECA conditions for the roots better. If life dictates that plant fertigation must be less frequent and daily heavy misting can’t be performed, then the mix of rockwool and LECA should be experimented with. I used your suggested layering method but I found that when I repotted, the middle layer of rockwool was pretty dense. I remembered you saying that your best orchid growth occurred that year you grew with semi-hydro with daily fertigation from the top. I am sort of doing that.

 

[big923cattleya]

So far, I have no idea what ‘good Leca’ is or what ‘bad Leca is??? I have no idea what either looks like.
I currently have 3 Leca-like products. One is the little terra cotta round or almost round pellets. If you break them open, they are terra cotta colored on the inside. A second one is also terra colored and round or almost round pellets. But when you break them open, the insides are light Gray.
The third, which I brought with me from Florida over five years ago is more of a mustard yellow color. The form is pellet like or pebble like but the outer surface is rough, not smooth like the other 2. It is not round!
A 20 pound bag of the terra cotta colored, gray inside stuff came with me. Since it is an additive I still have some. The bag said “Hydroton” on the outside. The other mustard colored stuff is loose so I do not have a trade name to share.

 

[Ray]

I don't know how accurate the info is, but I have been told (by the sole hydroponics store in Wilmington NC) that the original Hydroton is no longer manufactured. It may be that someone bought the name and is using it on a different manufacturer's product. The shop now carries CYCO Hydro Clay, which I find to be acceptable.

The only one I avoided like the plague was Aliflor, and that was because they used kerosene or diesel as the binder when making the pellets, anticipating it would burn off during firing, leaving extra porosity. Unfortunately, several container hit the US that were underfired, so reeked of fuel and killed anything planted in it.

The color of the clay is, to some degree, controlled by the raw materials, but might be a remnant of the firing schedule, as well. Terra cotta clays contain a lot of iron. If fully oxidized, they are beige to peachy to orange color. When the firing atmosphere is fuel-rich and a reducing environment, they will be gray. What often happens is the firing is a bit fuel-rich to drive off the additives used to form the pellets without oxidizing them, but when air hits the still-hot product after firing, the surface starts oxidizing.

There are a number of properties that may make one brand better for an individual than another:

►Particle shape - spheres offer the most fee void space, but easily move around in the pot, acting like a container of marbles, making it harder for the plant to stabilize itself.
►Particle size distribution - the narrower, the better.
►Average particle size - the larger the particle, the larger the pore size between them.
►Surface texture - smooth = better wicking.
►Degree of absorption of solutions - more = better wicking and duration between waterings.
►How much of the absorbed solutions are readily released again - more = slower mineral and waste buildup.
►Chemistry - I have left this for last, not because it's unimportant, but because I've learned something recently:
The LECA I have used over the past several decades have all been pretty much chemically neutral. I even left some sealed in a container of distilled water for a year, yet saw no rise or fall in pH. However, Miss Orchid Girl has moved away from S/H culture because the only locally-available LECA for her was formulated with an alkaline clay, so the rhizosphere pH climbed over time. COnsidering the low water solubility of these material, I'm not sure how you'd test that before use.