Trying semi-hydroponic medium/technique

[xscd]

I've grown a few orchids for 10 years or so here in the arid eastern plains of New Mexico, US. The cattleya alliance and phalaenopsis seem to like me. I generally do very well with them. My one paphiopedilum grows like crazy with new plantlets but never blooms. The dendrobiums that I have bought or were given to me, with one lone and spectacular exception, have all developed dendrobium leaf spot and died.

(Is it just me, or do all the dendrobiums sold in popular stores like Wal-Mart look great right from the grower in Hawaii or elsewhere, but quickly develop leaf-spot and drop their leaves once they are at home. It makes me think that the commercial dendrobium growers are spraying anti-fungals all the time to keep the leaf-spot at bay and keep the plants looking good up until the time they are sold, knowing well that the greatest percent of them will succumb to leaf-spot soon after they are bought.)

I recently learned about semi-hydroponic techniques and medium (PrimeAgra "leca" (lightweight expanded clay aggregate)), and although I have a few apprehensions I am interested in the technique. I have repotted my paph. into a semi-hydro translucent pot with PrimeAgra, and plan to place more of my orchids into s-h conditions when I repot them, just to see what happens and how they grow.

Until now, my standard orchid medium has been fir bark that I bought as large chunks sold in large bags locally as "decorative mulch" and which I ran through my chipper shredder to get down to size (1/4 - 3/4 inch) then washed and screened to get rid of the powdered bark and smallest particles. For the pahiopedilum, I mixed about 4 parts of this bark with 1 part sphagnum peat moss and 1 part vermiculite, and over these last 2 years while the paph. has been in this mix and a generous sized pot, it has grown like a weed with numerous side shoots, but not a single bloom. Paphs are still a mystery to me, although I like them very much and would enjoy growing them as well as I do my phals and cats.

Anyway, I'm curious as to how the semi-hydroponic technique and the very interesting inorganic planting medium will work. I have read various posts on the subject, not all of them favorable to the technique, so I'm just going to see how things go and adjust my technique/medium from there.


Best wishes all,
Steve / xscd
New Mexico, US

[Cynthia, Prescott, AZ]

I'm not into S/H, so can't comment on it. However, a couple of comments.

I would make it a point to stop using vermiculite, and start using perlite as a substitute. I used to use vermiculite (50%) in my mix for the last 20 years. However, the current mineral for making vermiculite comes from Africa, instead of Utah, where infinitesmal amounts of asbestos were sometimes found. The stuff from Africa, or where ever it is coming from now, has proved deadly to my plants, and I think it is the very rapid break down that is the problem.

Most Dendrobiums, and almost always the ones from home centers and the like, should be allowed to get very dry in winter before watering when not in growth or bloom. If in doubt, add a few extra days dry. The leaf drop may be natural, and should not be considered a problem. If one of your Dens is doing fine, don't change anything for that plant, it probbaly has very different parents from the run of the mill Dens. All Dens while growing should be watered very liberally.

For the Paph, you could try more light, or, and this is the time of year for it, cool the plant down an extra 10 to 15 degrees for a few weeks.

[xscd]

Thank you Cynthia. I actually intended to say perlite (because that's what I used in the paph. mix), but thank you for the information and warning about vermiculite. I had no idea, and will avoid it.


Thanks also for your advice to keep dendrobiums on the dry side when not actively growing or blooming. I'll make sure to remember that.

I'm great with cats and phals, but my latest challenge (and interest) is in paphiopedilums. I really love these plants, but although mine grows vigorously, it never blooms (in the 6-7 years I have had it). It's a mystery to me, and I wonder what I need to provide to encourage it to bloom, or what I'm doing wrong to prevent its blooming. The leaves, new growths and roots are all very numerous and healthy-looking, so I'm not sure what might be the problem.

[gerneveyn]

I have a couple phalaenopsis and a cymbidium orchid in s/h. I like it. It's best to repot into s/h when there is active root growth.

[Cynthia, Prescott, AZ]

xscd, do you have a name on that Paph? It may have a recent ancester with special needs to initiate blooming. If not, at least try the month or so of lower temps. I recall a story about one Paph species that you had a hard time giving away for many years (don't remember which it was), until it was discovered that the plant needed a chill to trigger blooms. Thereafter the plant went at very high prices.

[Daniel S. Barrett]

i know from blooming my own paphs, that the paphs with a patterned leaf needs a night temp of 60-65 degrees, and the solid green leaf ones need a night time temp of 55-60 degrees to bloom. so, if you can get your night temps to at least 60 degrees, both should bloom with no problem, mine do.

[xscd]

Originally Posted by Cynthia, Prescott, AZ

xscd, do you have a name on that Paph? It may have a recent ancester with special needs to initiate blooming. If not, at least try the month or so of lower temps. I recall a story about one Paph species that you had a hard time giving away for many years (don't remember which it was), until it was discovered that the plant needed a chill to trigger blooms. Thereafter the plant went at very high prices.

Thank you very much for your response, Cynthia. Unfortunately, the paph is untagged and I have no idea what it is. Regarding the lower temperatures, up until this winter I have kept it in the greenhouse during the cold part of the year with my dormant carnivorous plants (Venus Flytraps, pitcher plants), with the thermostat set at 55 degrees. My dormant plants were on the floor where it was usually considerably cooler, and the paph was on a bench where the temperature didn't get below 55, and usually warmed up during the day into the 60s-70s Fahrenheit.

I have just repotted this very large clump with dozens of mature plants all from the original single paph into a semi-hydroponic pot with PrimeAgra expanded clay aggregate pellets (coarse 8-16 milimeter size) and brought the pot inside the house for the winter, to see if precisely the opposite of what you mentioned--a warmer winter temperature instead of the colder one it has received these last 4-5 years--might encourage it to bloom.

I'm also going to do some research into specific fertilizers. I tend to like and use Miracle Grow and Miracid, with additions such as fish emulsion, epsom salt (magnesium sulfate) and powdered kelp extract (for a wide range of micronutrients). I'm going to see if I can find a local source for a few pounds of calcium nitrate also, to add to my usual weak fertilizer mix.


Thanks again for your comments, ideas and suggestions.

best wishes,

Steve / xscd
New Mexico, US

[Cynthia, Prescott, AZ]

Steve, with Daniel's comments on leaf pattern, I'd like to hear from you what what kind yours has. Here ia an interesting site, check out the articles under 'Questions':
http://www.ladyslipper.com/index.html
Esspecially this stuff about supplimenting with oyster shells:
http://ladyslipper.com/calsub.htm

[xscd]

Originally Posted by Cynthia, Prescott, AZ

Steve, with Daniel's comments on leaf pattern, I'd like to hear from you what what kind yours has.

Thank you Cynthia, and thank you also Daniel for your comments. My paph is one of the mottled-leaf (usually warmer loving) varieties. The leaf span on each individual plantlet is only 4-7 inches. I would post a photo of it except that I am a new member and am evidently not allowed to post pictures until I have written at least 15 messages to the forum.


Once I reach that limit, I'll post a photo in the gallery, or a link to a photo at my website. In fact, perhaps I can do that now--

No, although I took a photo, the forum won't let me post a URL (link) yet, until I have posted 10 messages to the forum.

Steve / xscd

[mayres]

So far my mottled leaved paphs rebloom twice with no special attention to temperature or other issues - maybe I'm just plain lucky or have the "easy" ones? :-)

[mayres]

I have one that bloomed about four months ago and now its blooming again - my first to bloom more than once in the same year!

[Cynthia, Prescott, AZ]

Well Steve, if the warmer temps work, revive this post and let us know. Mean while, good luck. By the way, check your # of posts in your profile later today. Sometimes it mysteriously bumps up to 10, the number needed to post pictures.

[xscd]

Originally Posted by Cynthia, Prescott, AZ

Well Steve, if the warmer temps work, revive this post and let us know. Mean while, good luck. By the way, check your # of posts in your profile later today. Sometimes it mysteriously bumps up to 10, the number needed to post pictures.

My gosh, you're right! My thanks to a certain super moderator.


So, here is the photo I took last night (in less than optimal light) of my non-blooming but otherwise apparently healthy paphiopedilum:



It hasn't bloomed in at least 5 years, probably 7.

Best wishes--

[Cynthia, Prescott, AZ]

I was told, can't remember if in person, or in his book, by Lance Birk that all mottled leaf Paph species could be identified solely by the pattern of the leaves. Now, this may be of no use, first because yours may be a hybrid, and second because, unless there is a specialist around who knows the patterns, we would need samples of all mottled leaf Paph species to compare to. I have only recently started to collect Paph species, and many don't appeal and will never be in my collection. So we need a joint effort of people who have Paphs to post pictures of any Paphs they think are close. Even if it is a hybrid, the is an outside chance we may be able to pick out one of the parents. Anyway, I will be checking the pattern against my plants.

[xscd]

Identification--
Thank you Cynthia for the information. I think I'll start to look at photos of paphs to see if the pattern looks similar to mine.

Semi-Hydroponic technique--
I ordered 2 pounds of calcium nitrate today to add to my fertilizer mix for this new semi-hydroponic orchid-potting experiment. I'm wondering if this paph might be one of the limestone-clinging, alkaline soil types. Perhaps it has a deficiency of calcium and needs more to bloom, although it grows just fine and had an extensive and very healthy root system with only one old and rotten root (that I trimmed off, of course) when I repotted the paph into a semi-hydro container a few days ago. A semi-hydro container is just any plastic container with holes on the side instead of in the bottom of the pot, in order to form a reservoir of some of the water/fertilizer that capillary action will draw upward through the leca (lightweight expanded clay aggregate, in this case, PrimeAgra brand).

Fertilizer mix--
My typical ingredients for my water soluble fertilizer mix are: Miracle Gro, Miracid, fish emulsion, powdered water-soluble kelp extract (Maxi-Crop brand) for a full range of trace minerals, and epsom salt (magnesium sulfate). Now I'll add calcium nitrate to that list and see what happens.

[daytriper]

There are so many mottled leaf paphs---has that "Maudiae" look to me.

[daytriper]

another close in both leaf shape and color is a Mark Hasegawa--but I still like the "Maudiae"--shape of the leaves and the color. It is hard to tell from a picture.

[daytriper]

Smiling---I have the answer--send me your paph and I will bloom it for you. It is a paph jungle here. You could not kill it here if you wanted to. I will send you my potted walkerianas---I can't pray a bloom on one of them.

[xscd]

Thanks daytriper for your offer-- --I think I'll see how the plant responds to its new semi-hydro, inorganic medium living situation. So far, after about a week, it looks good and is sucking up the nutrient solution at a fairly rapid rate. That's one thing I like about the semi-hydroponic technique so far. If one uses a translucent pot, one can see the root growth and see exactly the rate at which the plant is taking up water/nutrients.

This paph was my first experiment with semi-hydro. Since then (in the last few days, I have repotted an African violet and a Cape Sundew (a carnivorous plant) into semi-hydroponic conditions as well, using the finer grade of PrimeAgra leca (lightweight expanded clay aggregate), the 4-10 milimeter size.

One of the largest buyers of the PrimeAgra inorganic medium in the U.S. is a commercial African violet nursery.

I'm curious to see how the Cape Sundew (Drosera capensis) does in the PrimeAgra, since the plant normally grows in acid soil and the PrimeAgra is neutral in pH (and neutral and inert in just about every other way as well).