Help with Phalaenopsis gigantea

[jpyerry]

I have a small collection of species Phalaenopsis orchids. All of my species phals are doing well with one exception, my gigantea. I have had my gigantea for about 2 months now, its largest leaf is about 3 inches long. All of my species have shown signs of growth, new leaves, new roots, etc. However, since acquiring the gigantea, it has shown absolutely no growth and I am starting to get quite worried about. I have it potted in a net pot with sphagnum moss. I keep my collection in a grow tent that has a 4 foot 4 bulb T5HO 6500K grow light system with photoperiod set for 18 hours, the orchid is set about 8" away from the light (I do not know luminosity because I still have not purchased a light meter). The temperature is a fairly consistent 72F with a humidity of approximately 75% and two small fans to circulate the air. I water it when the moss feels fairly dry and crunchy, with a regime of MSU fertilizer (45mL per gallon of water), Physan 20, a few drops of SuperThrive, 2mL ProTekt, and every 4 weeks 15mL KLN rooting concentrate, every other watering is plain water. I adjust pH to 6.2 to 6.6 using citric acid crystals and I use distilled water or RO water when possible, if I must use tap water, I dechlorinate it first (my city water has a fairly low TDS, but I don't have specific figures right now). I keep the plant at about a 30 degree angle to prevent water from pooling in the crown. If anybody has any suggestions on how I can get things moving in the right direction, I would be very grateful. I do know that giganteas are on the slower side of growth, but I just keep worrying about this plant, I really want it to do well. Thanks in advance.

[orchids4me]

I like the regimine you have going on I may take your advice here. To my knowledge these guys are sloooooow growers. I have 3 seedlings right now. And one I had lost didn't grow much at all in a year I had it. So I thing it ranks with the cornu-cervi as a sloooooow grower I've gotten new roots and one leaf that it and its taking its sweet time to grow out.
I'm sure other members will have advice or correct me if it not a slow grower but I read somwhere on here they were and from my own experience with seedlings it has been the case.
Hope this helps
Emmaye

[Ron]

Hi Very interest in all the work you are doing to keep it going.
I will be getting a flask of them in a few months time so will keep an eye on how your responds.
Personally in my climate spag moss is a phallie killer, it would not hurt too pull of the moss off and have a look at the roots, replace the moss with fresh moss.
Personally I would also back off on the fertilizer until I see signs of new growths.
Treat it like any other Phal species, warmth and humidity.

[psyc1210]

I don't know about growing under lights at all, but I keep my gigantea in the brightest light I can give in my ESE facing window. I also have it in an 8 inch net pot with coconut fiber. From what I understand, they don't like to have "wet feet". Mine gets watered every day, as it dries out fairly quickly in the net pot with coco fiber. It is definitely a very slow grower. I have had mine for 3 years, and it has grown 3 leaves since I've had it, and some nice roots, but still definitely slower growing than any other Phals that I have. How often does your gigantea get watered. I know you said when the moss is crunchy, but approximately how often is that?

[jpyerry]

Because I have such a high humidity in my grow area, the media takes a while to dry out. As such, this particular plants ends up getting watered about once every two weeks.

As for lighting, most of my windows are small and not much light gets through, so I am forced to grow under lights. I also own an HPS HID 1000W light that I grow vegetables under. It might be possible to move it to this light, I worry it might be too much though and I keep that area at 40% humidity so the pollen of my tomato plants does not become inactivated due to high humidity. But it might be possible to provide additional humidity for the one plant, just have to get creative. There seems to be quite a lot of conflicting information on light for Phalaenopsis gigantea, some say as much light as possible and others say give them normal Phalaenopsis light, not sure who is right and I don't want to kill the plant by giving it too much light.

Rambling aside, if more light is the ticket, I can give it more light. And if sphagnum moss is not the way to go, that can be changed as well. I am hoping that those that are experienced can tell me what is best, though I am sure there are many ways to successfully grow this plant.

Anyways, I always appreciate everybody's help.

[psyc1210]

Peter Lin had told me to grow the Phal gigantea in as much light as I could provide indoors. From what I understand they are normally found in nature higher up in the trees where there is much less shade. Here is a link to my Phal gigantea... not sure if it will help you or not. How to pot Phal gigantea?

I haven't bloomed mine yet, but I haven't killed it either. It is growing, just slowly, so I guess I'm doing something right.

[Brooke]

Slow doesn't come close to describing the growth habit of a gigantea

First this isn't the typical leaf growing season of the gig, for me that comes in the middle of summer so yours should be about the same, I'm zone 6a. I only get two leaves a year on a mature plant and on my seedling last year I only got one. Did I mention they are slow?

If it is in a net pot with sphag and it doesn't dry out for a couple of weeks, either increase the air movement or reduce the amount of sphag in the pot. Could the net pot be too big for the roots? Under high output T5's 8" from the light you should have faster drying than you are getting.

The gig can grow with your other Phals but to get them to spike at maturity they need higher light. They do grow in the tops of trees but receive constant air movement so the leaves don't burn. It also has a wax coating to protect it from the heat.

You possibly could back off the chemicals. If you can drink your water you don't have to dechlorinate it. Only use Physan if you have a problem. A little fertilizer each watering with a good flush every couple of weeks should be sufficient. A little Superthrive is fine and the rooting hormone on occasion might help but if it is not the root growing season, you aren't going to force them to grow roots or leaves. Each Phal species is genetically programed to grow and bloom on their specific timetable, not ours.

Did I mention they are slow?

Brooke

[jpyerry]

Well, I just couldn't hold back anymore, so I decided to repot my gigantea. Since moisture retention seems to be of utmost importance with this particular plant, I decided to change the sphagnum moss to medium bark. When I unpotted the plant, I found about half of the roots had died off since the last repot when I got it. This would explain its lack of growth. With hope this will breathe some new life into it, if it doesn't kill it.

[Brooke]

I'll keep my fingers crossed for you because the growing season is approaching.

Brooke

[catasetum-ian]

Originally Posted by jpyerry

Well, I just couldn't hold back anymore, so I decided to repot my gigantea. Since moisture retention seems to be of utmost importance with this particular plant, I decided to change the sphagnum moss to medium bark. When I unpotted the plant, I found about half of the roots had died off since the last repot when I got it. This would explain its lack of growth. With hope this will breathe some new life into it, if it doesn't kill it.

the phal gigantea word caught my attention,i rescued several phals before and also one gigantea. usually i will discard all the shag moss, trimmed all the black or rotten roots, then dip them in antifungal solution of your choice then i would just mount them on fern slat without moss but u had to water them about 2-3 x per day (that is for my local climate here) and temporary keep them in shady area so that you will lower the transpiration rate in order to balance for the reduce workload capacity of the injured rooting system.
good luck.......

[jpyerry]

Unfortunately for my gigantea, it has indeed died.

I bought a new one from the same vendor, so hopefully it is from the same batch of plants.

I potted it in a net pot (that has even larger holes than the last one) in medium fir bark and I have hung it about 2" away from my T5HO light. It dries out in about a day, so I have to keep up with the watering.

Fingers crossed, I hope this one will do better.

[psyc1210]

Originally Posted by jpyerry

Unfortunately for my gigantea, it has indeed died.

I bought a new one from the same vendor, so hopefully it is from the same batch of plants.

I potted it in a net pot (that has even larger holes than the last one) in medium fir bark and I have hung it about 2" away from my T5HO light. It dries out in about a day, so I have to keep up with the watering.

Fingers crossed, I hope this one will do better.

you are saying 2 inches away from t5 high output bulbs?

[jpyerry]

Yes, it is about 2 inches from my 4 bulb 4 foot T5HO fixture.

[psyc1210]

Originally Posted by jpyerry

Yes, it is about 2 inches from my 4 bulb 4 foot T5HO fixture.

I will let someone else with t5 experience help you with this, but I was under the assumption with t5HO bulbs, the plants should be placed back further than that.

[jpyerry]

Yeah, I have most of the phals two to three feet from the lamp. But, I was told that Phal gigantea should receive as much light as possible. So, I put it as close to the lamp as I could get it. I also have a 1000 Watt HPS fixture, but I thought that might be overkill.

[psyc1210]

Originally Posted by jpyerry

Yeah, I have most of the phals two to three feet from the lamp. But, I was told that Phal gigantea should receive as much light as possible. So, I put it as close to the lamp as I could get it. I also have a 1000 Watt HPS fixture, but I thought that might be overkill.

Yes, Phal gigantea should get more light than other Phals, but I am not sure that being that close to t5HO bulbs is necessarily a good idea. Hopefully someone else that uses t5 bulbs will chime in.

[psyc1210]

Forgot to ask, how long have you had the gigantea in the current setup?

[jpyerry]

About one week so far.

[Ron]

Hi, perhaps also it would pay to check out how hot it is growing them so close to the lights.
While I have not received my flask of P. gigantea yet, i will be growing it in the same conditions as most of my species phallies. Hot humid and under 70% shade cloth out in the greenhouse.

One thing you should never ever forget is Phalaenopsis are tropical plants from tropics.
They love heat of 87 to 90+F in their growing season.
I have for example Phal schilleriana 9 months out of flasks mounted and hanging on the wall in the greenhouse and despite the fact we are slap bang in the middle of winter most are have good flower spikes on them some as many a 3 spikes.
Get the culture right and they will respond quickly with good growth.
Do a Google search for Phalaenopsis gigantea and it will bring up some amazing photos on other sites.
Leaves over 3 feet long and 18 inches wide, covered in flower spikes.

Enjoy the adventure into growing some different challenging Phall species
Cheerio

[katrina]

Originally Posted by jpyerry

Yes, it is about 2 inches from my 4 bulb 4 foot T5HO fixture.

Are they 54 watt bulbs? If so, JoBeth is right. I don't keep my catts that close to those bulbs. The light right at the bulb is over 3000fc and a couple of inches down it'll still be 2500 fc or greater. I don't grow gigantea but I do grow a gig cross and that's going to be too much light for it.

On top of the intensity at that closeness...you also have to watch the heat. This is probably an even bigger issue...especially for a phal. I've scorched a couple of catt leaf tips that got a little too close.

[jpyerry]

Well, I actually have some good news to post in this thread today. I got home after my weekend shift and performed my cursory examination of my collection. I took a look at my gigantea and despite the poor appearance of the rest of the plant, I saw the smallest little bump in the crown, and it looks like I might have the start of a new leaf growing! If this is the case, I will be so happy! If it gets a leaf, I will be sure to post a picture since I finally have a digital camera again.

I have been caring for the plant differently lately, since there were concerns about the plant being to close to my T5s, I moved it to about two feet from the lights, no results after a few weeks, so I moved it to about 4 feet from the lights for a few weeks now. I have seen some green return to the yellowed areas (still has a poor appearance though), and now possibly a new leaf.

I have a sneaking suspicion that the extremely high light recommendations must be for well established mature plants and that lower light conditions are probably better for smaller plants. It would make sense because in nature the plant probably starts out well shaded by its tree mount and as it grows more leaf area would be exposed to the sunlight.

I feel like a real nerd being this excited about such a small triumph. But, then again I have found orchid growing in general is a long series of very small triumphs.

It is a sad day to, for those of us that grow carnivorous plants, my struggling Cephalotus follicularis finally died this weekend after some extensive damage secondary to scale insects.

[koshki]

For the phal gigantea, OW recommends 800-1000 fc..."a very shady environment is recommended...". Which means that close under your T5s is way too close. I don't put my phals under any artificial light, in a north-facing window.

Plus, I wonder at your lighting for 18 hours. I think that is WAY too much time under lights. I only run mine 14-16 hours, and for some plants that is too much. Again, none of my phals are under these lights.

[psyc1210]

Originally Posted by koshki

For the phal gigantea, OW recommends 800-1000 fc..."a very shady environment is recommended...". Which means that close under your T5s is way too close. I don't put my phals under any artificial light, in a north-facing window.

Plus, I wonder at your lighting for 18 hours. I think that is WAY too much time under lights. I only run mine 14-16 hours, and for some plants that is too much. Again, none of my phals are under these lights.

Are you able to bloom your Phals in North facing windows?

OW may have the suggestion for 800-1000 fc for gigantea, however many other sources say higher light for gigantea if you want to get it to bloom. P. gigantea are found high up in the trees, and get more sunlight than other Phal species usually receive.

I do agree that the T5 lights sound like it is too much for the Phal.

[koshki]

Originally Posted by psyc1210

Are you able to bloom your Phals in North facing windows?

Yes, I am. They are in a sunroom, with three sides, the longest of which is northish facing (probably more like NNE), but the phals are toward the east side of the room, but not directly in the east-facing windows. (One has not rebloomed for me, and I've been thinking of "deacquistioning" it, but maybe it needs more light.) But they get a little boost of light early in the morning, although I'm careful to keep them out of direct sunlight.

I don't grow the gigantea, so I'm only quoting others, not speaking from experience!

[psyc1210]

Originally Posted by koshki

Yes, I am. They are in a sunroom, with three sides, the longest of which is northish facing (probably more like NNE), but the phals are toward the east side of the room, but not directly in the east-facing windows. (One has not rebloomed for me, and I've been thinking of "deacquistioning" it, but maybe it needs more light.) But they get a little boost of light early in the morning, although I'm careful to keep them out of direct sunlight.

I don't grow the gigantea, so I'm only quoting others, not speaking from experience!

Sounds like a nice setup!!

No worries, I was just providing the info I've read and noticed working with my P. gigantea

[jpyerry]

I try to run my plant lights to match the seasons, so I am soon going to start slowly cycling them to a 10-12 hour day. I wish I had a setup so that I did not need to use grow lights, but that is my situation at the moment and we all have to live with what we have. Another thing, I really need to get a light meter. It is on my wish list, but more orchids always seem to trump that list. Anyways, I am just ecstatic that things might be turning around for this plant. But I am still proceeding with cautious optimism.

[BGGraham1]

If you have a smart phOne, i.e. Droid or iPhone, there's a light meter application. Works pretty well.

[jpyerry]

It is confirmed, definitely a new leaf and two new roots forming!

[Ron]

Hi, it is looking good, definatly a healthy new roots starting to grow.
Best of luck with it
Cheerio