"What do Orchids Eat?" Experiment

[Rick]

Well I did add 1 TBSP/gallon of Epson Salts.

As a single shot for an entire summer that's OK, but I wouldn't do more than 1/8 tsp/gallon on a weekly basis in low hardness water. Magnesium concentration should stay below calcium concentration.

 

[shadytrake]

As a single shot for an entire summer that's OK, but I wouldn't do more than 1/8 tsp/gallon on a weekly basis in low hardness water. Magnesium concentration should stay below calcium concentration.

Good to know.

 

[shadytrake]

I did a quick check of the orchids this am and I see new growth on 2 Phrags that were droopy before. I'm hoping that is a good sign.

I got my KLite today but I'm not doing a feeding until I filter the kelp liquid. I think I will start with a very diluted mixture.

Edit to add: checked the Den lindleyi tonight and I counted 7 new growths. 3 new growths are in the bare area showing in the most recent photograph so those are definitely new after the experiment started.

Also, I checked my Mc brysiana that has been in steady decline and pest ridden for the last 1 1/2 years and I find no evidence of new scale and oh my, a bloom spike is working. Now this might be the kiss of death, but I'm hoping not. I'm kind of a species nut so I get really attached to them.

 

[shadytrake]

Wow what a heat wave! I haven't fertilized because the temps hit 100 twice this week. I still see crazy new growth with just plain Memphis water. I'm going to fertilize late tonight when the temp drops.

Will take pictures too. The bloom spike on Mc brysiana is confirmed. It is 1/2" long and growing. Would also like to report that our Aerides multiflora is putting out new fans that are strong and not weepy and the Vandopsis parishii var mariottiana is growing roots as thick as my thumb. These are exciting results!

 

[shadytrake]

Okay it has still been so hot that I am afraid to fertilize. I did take the opportunity today to re-pot some of the Paphs.

After doing some more research about the natural habitats, I tried to create a better media.

For example, most of these paphs grow in a limestone area so I dissolved some lime in the sphag moss and added some regular gravel and crushed oyster shells.

You can see the new leaf on Phrag Wossen. I am happy with the new root growth but I suspected that our heat was stressing it so I transferred it from plastic to a "cool pot."

You can really see the difference in the original growth vs the high K growth on the Paph delenatii. The leaves are not only 1/2 the size, but they turned a sickly yellow. The good news is that upon inspection, I see a fat new root (not pictured) and new leaf growth (pictured).

The Paph vietnamense has new root growth and a new leaf starting. The Paph Emma Decker and Becky Fouke both have new fat roots.

The most striking is the Mexipedium xerophyticum. You can see the new leaf is almost double the size of the old growth.

Order of pictures:
Phrag Wossen
Paph delenatii var vini x sib (dunkel)
Paph vietnamense
Paph Becky Fouke
Paph Emma Decker
Mexipedium xerophyticum

 

[Rick]

The use of oyster shell amendments with K lite is a bad idea.

The high bicarbonate (not calcium) increases pH and interferes with photosynthesis, impedes root uptake of CO2, and reduces nitrate reduction to ammonia. It is also a phosphate sponge that (initially until saturated) will keep the plants from uptake of phosphate.

These are things I used to do in the old days that never worked using MSU.

Also delenatii come from low pH sandstone areas (not limestone).

I'd get rid of the oyster shell.

Are your plants outside without cooling? I'm feeding almost every 2-3 days at 10-20ppm N.

 

[shadytrake]

Oh that is interesting. I didn't know that. I'll brush it off then. I read a lot about top dressing with oyster.

That's the difference between us lay people and you chemistry experts!

 

[Rick]

Are your plants outside without cooling?

If they are experiencing 100 F in the shade, they are probably going to 110 with sunlight hitting them. You need to worry about some serious shading and misting instead of feeding for sure.

My GH has been hitting the mid to high 80's (even with mid 90's outside). I'm feeding every 2-3 days at 10-30ppm N.

 

[shadytrake]

Also delenatii isn't found over limestone, but over granite and sandstone (acidic).

Are your plants outside without cooling?

If they are experiencing 100 F in the shade, they are probably going to 110 with sunlight hitting them. You need to worry about some serious shading and misting instead of feeding for sure.

My GH has been hitting the mid to high 80's (even with mid 90's outside). I'm feeding every 2-3 days at 10-30ppm N.

Right on the delenatii - chemo brain kicked in there while I was typing. I didn't add lime to it's moss but I did add the oyster shell (which I will remove tomorrow).

No, they are in a shade house with a 6 station Orbit mist system on a battery timer. It hits at 6 different times plus if I see the temp hit 90, I go out and manually start the sequence. Plus I have 3 fans circulating.

I have a 30% shade cloth over top of the roof and the paphs/phrags are in the coolest part. Unfortunately it is a hot summer.

My Catts are going to bloom like crazy for sure.

 

[Rick]

Oh that is interesting. I didn't know that. I'll brush it off then. I read a lot about top dressing with oyster.

That's the difference between us lay people and you chemistry experts!

I used to use a lot of oyster shell or aragonite sand with my mexipedium. The plant totally changed when reducing K with bigger leaves, fast growth and much reduced rot problems.

I recently got to compare my plant to Ed M's. My plant is a piece of his, but is now bigger. Ed made his own version of low K feed last year, but it has a bit more PO4 and a slightly higher percentage of ammonia. He also keeps a lot of oyster shell in his Mexi pot. His is growing at a very good rate, and is having a fantastic blooming, but it is yellower and has smaller leaves.

There could certainly be other factors causing the difference in growth, but since we live on opposite sides of Nashville, and are pretty diligent about temp and humidity issues, climate is probably not a significant difference.

Lots of folks (including myself) swore by calcareous pot amendments for Mexi and many other species, but I'm actually finding it to be a detriment with the present nutrient system I'm using now.

 

[Eric Muehlbauer]

I always stop feeding my paphs when temps are regularly in the 90's....and I generally avoid repotting until things cool in late August. Of course, that's not always possible...squirrels or wind knock pots over, a mix turns out to be rotten or packed, but if all is well I wait until cooler weather to repot paphs.

 

[shadytrake]

Oyster shell is 90% gone now. Good thing I went out there to do a last check as I found two slugs making their way up the newly repotted baskets...effers!

They are now squashed and I went ahead and quickly brushed off the shell and re-potted the Mexi into a stone/orchiata/hydroton mixture with a tiny bit of moss. Then I flushed it with water.

Good thing I didn't buy the 50# bag of shell. The feed store had opened it so they just sold me a scoop.

 

[shadytrake]

Well I'm doing pretty well with the plain water. I re-potted a bunch today with my new mixture and most of them look great. I also took the opportunity to kill the wayward slugs (man this is a bad year for them).

I definitely think I am on the right track.:clap:

These are:
Paph insigne forma sanderae
Paph glanduliferum
Paph primulinum
Paph concolor
Paph armeniacum
Paph Hawaiian Illusion

 

[Rick]

How long have the insigne and glanduliferum been in your collection?

 

[Eric Muehlbauer]

Sady, have you tried iron phosphate on your slugs? it's a bad year here too.

 

[shadytrake]

How long have the insigne and glanduliferum been in your collection?

2 or 3 years for the insigne, 1 year for the glanduliferum.

I believe the glanduliferum was a seedling leftover from Jo Levy because they are both tiny.

 

[Rick]

2 or 3 years for the insigne, 1 year for the glanduliferum.

I believe the glanduliferum was a seedling leftover from Jo Levy because they are both tiny.

Couldn't quite figure it out. The first 2 pics are the insigne, the second two pics are 2 different "glanduliferum" and the last pic on the top row is the primulinum.

I know Jo was pretty hard core about using Garay's taxonomy on that "glanduliferum" complex of PNG paphs. They may be gardneri or wilhelmineae (and then they are potentially mature growths). If they are praestens then they have a ways to go.

 

[Rick]

Sady, have you tried iron phosphate on your slugs? it's a bad year here too.

I use that too. Bad in Nashville too.

 

[shadytrake]

Couldn't quite figure it out. The first 2 pics are the insigne, the second two pics are 2 different "glanduliferum" and the last pic on the top row is the primulinum.

I know Jo was pretty hard core about using Garay's taxonomy on that "glanduliferum" complex of PNG paphs. They may be gardneri or wilhelmineae (and then they are potentially mature growths). If they are praestens then they have a ways to go.

Right and they were labelled gardneri originally, but didn't Kew combine them and now gardneri is glanduliferum? I keep an inventory with these notes so I don't forget plus I keep the original tags in a bag away from UV.

 

[shadytrake]

Sady, have you tried iron phosphate on your slugs? it's a bad year here too.

How is it applied?