LECA & S/H: good or evil?

[TyroneGenade]

Hi all,

Continuing my exploration of bark alternatives for slipper orchid growing I have decided to explore LECA next. One post from 2006 said:

I've been using the new prime-agra* for quite some time now... and have come to one final conclusion... slippers friggin hate it. Almost every paph and phrag (except the wet loving phrags) rotted like crazy... Use the new stuff with extreme caution.

*I understand there was some acrimony around the issue of the new prime-agra and would appreciate it if we could have a friendly discussion and focus on LECA in general instead of opening old wounds.

Agra, hydroton etc... they are just LECA: light expanded clay aggregate. I can see, from http://www.slippertalk.com/forum/showthread.php?t=17757, that success is possible. Reading the older, first few threads on this subject there seems to be only problems and no real solutions.

So, what I would like to know is the following:
1. how was the mystery of the dying Paphs solved? (Lance you seem to have chased the problem from what I can tell from the various threads, what did you conclude?)
2. water retention: how frequently do you water?
3. fertilization: what ferts work well, which don't?
4. how often do you need to repot?
5. are you mixing anything else into the LECA?
6. is any pretreatment needed?

 

[bullsie]

I use leca alot. Except for a few plants, like Phals and Paphs. I have put Paphs in it and they did well, but if I missed watering (as in a not too long ago illness) I had really dead Paphs. I am just now contemplating going from sphag to leca for my Phals. But I will tell you one thing:

ALL LECA IS NOT THE SAME!

You may have success with one variety and total failure from another. I tried one brand and had total disaster. Tried another with wonderful success. Recently tried a third brand with good success also. To a great degree it will depend on what fits your needs or what you are able to give it.

For your questions:

1. I don't know
2. depends on the orchid species
3. I use Dyna grow, Neptune, a home made one, a little MSU once in a while
4. when the plants grow out of the pot and that usually depends on maturity level.
5. just leca
6. I just rinse and plant. No rooting hormone, no pretreatment.

My two cents.

 

[gonewild]

So, what I would like to know is the following:
1. how was the mystery of the dying Paphs solved? (Lance you seem to have chased the problem from what I can tell from the various threads, what did you conclude?)

I concluded that when they produced the "new" PrimeAgra it had a pH problem and residual salt excess that leached out. I stopped using it. Ray can address this better maybe they got the problems resolved.

2. water retention: how frequently do you water?

The s/h watering method works just as Ray says it does in his method instructions. But I found that the plants grew better if I ignored the s/h concept and watered the Hell out of them overhead. I think the s/h concept is great for small indoor collections or growing areas where it is not easy to water with overhead applications as frequently as needed.

The best thing about leca is that you can't overwater with it. I like to water a lot... like several times per day.... so leca is wonderful!

3. fertilization: what ferts work well, which don't?

I used MSU at the time at 125ppm N and it worked very well. I also alternated with applications of Calcium Nitrate/Mag. But I did not rely on only the wicking from the s/h method I overhead irrigated as if the s/h did not exist so I had extra "flushing". The s/h concept of side holes and wicking works great along with normal water practices and you have the added benefit that if you leave them unattended for a week or so they get wick watered.

Now I would use K-lite. Basically the leca is just another form of media so the fertilizer remains basically the same.

4. how often do you need to repot?

Never. Only when the roots get too crowded. The media does not break down and if you maintain the nutrient regime correctly the salt never get out of balance.

5. are you mixing anything else into the LECA?

Limestone for lime loving plants.

6. is any pretreatment needed?

Rinse out any fine dust.

 

[Hera]

Don't let the plants get too cool. I lost a few plants after a show where someone had put them in a cool green house and the roots rotted. Personal opinion is keep them over 60.

 

[keithrs]

Hydroton is getting hard to find... I think Ray had said that he has not had problem getting his product. Hydro guys have been switching to growstones. I have no personal experience with growstones or with s/h. I do use leca in almost all my potting mixes to add air movement to the mix.

 

[cnycharles]

ditto to the 'keep things warm', especially if you have phals that like to be warm, because water evaporation will cool the base of the plant, which will make them sick and die (experience)

if you want something to be cool, or cooler, then this is great

 

[Rick]

I have a handfull of plants (I think all phrags) in hydroton in SH. I just remembered I put a paph tigrinum in it for a couple of years SH and it did good (but never bloomed), and then I switched it to basket a couple of years ago (its doing even better, but still blasting).

I recently posted a pic of a large Phrag longifolilum.

The pot is split on that plant, so I'm thinking about repotting. Otherwise its been in it for several years.

I think there is enough of a CEC to this material to worry about K accumulation over time. The big plants have done fine from the start, but I've had several failures when trying to do the same thing with a single division in its own pot (Until recently with low K).

With SH its pretty much continuous water, but if it sits around for more than a few days, I usually dump it out and replace with fresh (unfertilized water).

I can think of a couple of plants that have or have had hydroton or some other brand of clay balls mixed with bark or sphag. Only one of those is still set up that way. A Paph barbatum. Its been in it for a few years and bloomed last year. It went into the system just before low K and its done very good. I water/feed it about the same rate as the rest of the potted collection. But I do keep the humidity >70%.

My low end temps for the last few years have stayed right at 60. But in the past I'd go to 55-58, and the Phrags were just fine.

 

[DavidCampen]

Hydroton is getting hard to find... I think Ray had said that he has not had problem getting his product. Hydro guys have been switching to growstones. I have no personal experience with growstones or with s/h. I do use leca in almost all my potting mixes to add air movement to the mix.

Hydroton is no longer manufactured but the hydro shops are selling a replacement product, brand name Hydrocorn:

http://www.horticulturesource.com/product_info.php?products_id=10087

 

[TyroneGenade]

Thanks for the info.

@Lance: do you fertilize with every watering or on a schedule?

Anyone have any photos of plants grown in LECA?

 

[Tom499]

I use S/H for all my paphs and phrags, which is maybe 30-40 plants.

I use rain water, I forget the ppm, but it is good enough for Sarracenia.
I either drill holes into plastic containers, or use regular pots with a saucer. The latter does give you more control and makes it easier to flush the pots.

I water often, and fertilise weakly every so often. For warmer growing paphs I use a windowsill heat mat as a cheap way to stop the roots getting too cold.

Transitioning plants from the bark mixes I often buy them in, into the S/H is the crucial stage. Very important to time it with root growth timing to ensure a swift establishment.

Here are:
Phrag. schlimii
Phrag. Lemoinierianum (Calurum (longifolium x Sedenii) x Sedenii)

Paph. Magic Lantern

 

[gonewild]

Thanks for the info.

@Lance: do you fertilize with every watering or on a schedule?

Anyone have any photos of plants grown in LECA?

Every watering fertilizer.

Sometimes, but not on a plan or schedule I will water heavy to flush out the media. I do this no matter what media I have and I do it when I feel like watering a lot not because i think it needs it on a schedule. But this is also followed soon with more nutrient solution.

Leca is a good media if you like to water and I like to water! If I have a situation where I can do it I run mist/foggers intermittently all day long. Orchids like to be wet but they need drainage.... and leca provides this situation.

 

[Ray]

Medium or culture technique as good or evil? I view that as a silly question, as there is SO MUCH MORE to "orchid culture" than that, and so much variability in each individual's conditions and mannerisms, that one cannot generalize.

I have about 100 slippers, both paphs and phrags, in LECA medium in S/H pots. I have not had issues with any plants that were not caused by me screwing something up.

Kept warm and wet, I view the combo as making it really easy to grow the plants.

Now that I am back to commuting 50 miles every morning, it also allows me to automate my watering, with a controller giving the greenhouse a 45-minute drenching and then shutting off. Right now it's a manual start (via an RF transmitter in my office), but it can also be done on a timer, for times when I'm travelling.

 

[TyroneGenade]

Medium or culture technique as good or evil?

Thanks for joining the conversation, Ray. Technically, good and evil are just the words we use for things which work and things which don't. Also, it is eye-catching.

Are you also fertilizing with each watering? And if so, how much? Have you experiments with other fertilizing regimes?

The issue of warmth keeps coming up. What seems to be the best temperature range?

I'm still interested in seeing some pictures of healthy plants/roots growing in the stuff. No picture, no sale... at least that's how it seems to work if you want to be believed.

 

[Ray]

Eye catching it is!

I feed at every watering; currently 50 ppm N using K-Lite. I have done so for close to 20 years. Dyna-Gro "Grow" at 15 ppm N, followed by MSU RO at 125, followed by the current K-Lite.

Like everything else, I don't think there is an ideal temperature range. I think the "warmth" is utilized to overcome the potential for evaporative cooling of the root system from the open, airy medium. If your environment favors rapid evaporation, the heat is critical. In my greenhouse, where I keep a minimum of 60F and the RH is high, it's not. In my case, I use the bottom heat to accelerate root growth in new transplants.

Look HERE for a few photos.

 

[cnycharles]

ah, a point I hadn't thought about... I had some problems with 'too cool' and some rot, but my humidity was always very low at the time, so that would 'drive' more evaporative cooling. if the humidity was higher it may not have been as much of a problem

 

[couscous74]

I've had good success with S/H and LECA. I've used Ray's PrimeAgra (old and new), hydroton, and aliflor. And it all gets mixed up as I repot and re-use media. Growing in an apartment under lights and on windowsills, I had a hard time figuring out when to water when I used organic media. S/H made it easy. I could water every day, or when the pots ran out. My paphs and phrags all had happy roots. The first time you repot a transplant from another media, you usually have a ton of soggy old dead roots.
I used RO water, and tried to only repot when I saw new roots poking out.

 

[The Orchid Boy]

Recently moved a Phrag. pearcei into S/H. It's putting out new roots and seems to be doing well. I use distilled water and K-lite. I'm thinking about experimenting with African violets and Venus fly traps in S/H since I have a lot of extra plants of each.

Phragmipedium pearcei in S/H

 

[TyroneGenade]

Eye catching it is!

The only thing useful I have got from news paper is the lesson of the value of headlines.

I feed at every watering; currently 50 ppm N using K-Lite. I have done so for close to 20 years. Dyna-Gro "Grow" at 15 ppm N, followed by MSU RO at 125, followed by the current K-Lite.

Is this full strength or is the strength further watered down for continual watering?

@couscous74: do you imply that you don't always water, but simply let the plants rest in the reservoir? How does your fertilizer regime compare to Ray and Lance's?

Look HERE for a few photos.

Thanks! I don't suppose you have higher resolution images? Would it be OK for me to use them in the talk (properly referenced)? You can PM me.

Thanks for all the answers and insight into the subject. I can see this would work very well in a well with good planning.

 

[Hera]

The comment about dead roots is also something that I noticed. New roots grow to take over for the old, but the old can't seem to adapt to the new environment. It dosen't seem to affect the plants adversely, but be aware of this and don't think you've failed to make a good transition the first time you repot. Wet adapted roots usually adapt to drier conditions, but dry adapted roots usually rot in wetter conditions. IMO.

 

[The Orchid Boy]

I also have my Phrag. pearcei sitting in water. I flush it every week or so and fertilize twice a month, flushing style using 1/8-1/4 tsp. a gallon.