Issues with Mexipedium

[Skoester]

Hi all,

I acquired a couple of great Mexipediums several weeks ago. About a week ago, seemingly overnight, one developed some large areas of brownish-red discoloration on the top of a few leaves and the underneath has smaller, brown, dryish looking lesions. The top discoloration reminds me of succulent plants that have been cold damaged.

I’m a bit stumped at this point on what is going on. The plant is in bloom and has put on a new bud. It has three stolons that continue to grow. The leaves that are damaged are not the lowest or inner leaves, which I would expect if due to watering. I’m super careful about not getting or leaving water on the leaves. And the second Mexipedium has received the same care in the same location and appears fine - watering about every 3-4 days, RO with K-Lite.

Sorry about the photos of the undersides of the leaves- will try to capture some with better light.

Any thoughts on what i might have done would be appreciated.

 

[SelectOrchids]

Potassium deficiency, typical, exacerbated by an excess of nitrates as nitrogen source... Usea 20-20-20 with urea and the problem is solved within a couple days, though it won't green again, it will stop that problem.

The symptoms are even more typical as one plant is affected ( and spiking/blooming will drain potassium from the leaves), and another one not. That only depends on the initial contents of potassium in the plant...

 

[Skoester]

Thanks for the quick response! I didn’t realize a potassium deficiency would show up that quickly and to that extent - sorry to have damaged the plant but sounds like a fairly easy fix- and nothing contagious which I had feared.

 

[merc]

Shipping stress maybe?

 

[Ray]

Nutrient deficiencies don't show up that quickly.

 

[SelectOrchids]

Nutrient deficiencies don't show up that quickly.

They do when you reach the deficiency level, it can appear 2-3 days after watering...

 

[Skoester]

Hi everyone, I took Roth’s advice and fertilized with 20-20-20 and at this point I’m no longer seeing additional damage. I noticed another new bud on it this evening.

While I’ve been growing plants for 50+ years I’m fairly new to orchids and appreciate the input on this- definitely had me stumped. Photos are of plant currently.

 

[Skoester]

Shipping stress maybe?

I don’t think so. The weather was still fairly cool when they were delivered and there were no signs of damage - the plants were beautiful and in great condition - came from Marilyn at Windy Hill. I felt sure it was something I had done incorrectly. What had me stumped, besides the fact that not all leaves were affected, was that the other mexipedium, receiving the same care, shows no issues.

 

[Heather]

Interesting…the one I got from her recently has had no issues. Flowering at the moment.

 

[Skoester]

Interesting…the one I got from her recently has had no issues. Flowering at the moment.

Beautiful! Love the foliage and the blooms. Looks like a large plant - did you purchase a division?

Marilyn has gorgeous plants. Some of the cleanest and best-rooted I’ve received (I’ve ordered Phrags and Paphs as well from her). I’m sure it’s something I’ve done on my end. The second one I purchased from her is showing no issues. Are you using MSU on yours? I thought I read that on one of your posts.

Love the bonsai pots with it - was planning on replanting into one when it’s done blooming.

 

[Ray]

I think this is a case in which nobody has enough information to go on, so pretty much ANY answer could be dead on or way off base.

The plant was acquired a short time ago. What was the feeding history? If it was fed adequately prior to acquisition, it is highly unlikely a deficiency occurred in a matter of weeks. If it was on the verge of a deficiency, a lot will depend upon what "K-Lite in RO every 3-4 days" means in terms of concentration.

A potassium deficiency being more common in plants that just bloomed might be correct (personally, I don't know that, one way or the other), but wouldn't that be more likely to appear in the lowest leaves?

To what might it have been exposed?

If feeding with a urea-based 20-20-20, I would think the urea would have muck quicker impact, as that is what is used in "green up" products, as urea is the favored nitrogen form for foliar uptake.

 

[Skoester]

I think this is a case in which nobody has enough information to go on, so pretty much ANY answer could be dead on or way off base.

The plant was acquired a short time ago. What was the feeding history? If it was fed adequately prior to acquisition, it is highly unlikely a deficiency occurred in a matter of weeks. If it was on the verge of a deficiency, a lot will depend upon what "K-Lite in RO every 3-4 days" means in terms of concentration.

A potassium deficiency being more common in plants that just bloomed might be correct (personally, I don't know that, one way or the other), but wouldn't that be more likely to appear in the lowest leaves?

To what might it have been exposed?

If feeding with a urea-based 20-20-20, I would think the urea would have muck quicker impact, as that is what is used in "green up" products, as urea is the favored nitrogen form for foliar uptake.

Ray,

Since I have some smaller plants that need watering every couple of days and many Phrags that are in LECA/Grodan (which to my understanding need a less concentrated solution of fertilizer even under traditional culture) I’ve been using a concentration of 1/8 teaspoon per gallon of the K-Lite.

In terms of exposure, the plant hasn’t been exposed to anything unusual under my care (that I’m aware of) and the 60+ other orchids I have aren’t exhibiting any similar or unusual symptoms. The plant was in wonderful condition when it arrived- as have been all the plants I’ve received from Marilyn.

 

[Ray]

FWIW, Since moving my plants out of a greenhouse into seasonal outdoors/windowsill culture, I feed once a week with about a 100 ppm N solution, no matter how it’s being grown - S/H, traditional LECA/cubes, or mounted. If it needs water more than that, water is all it gets in between.

 

[Heather]

Beautiful! Love the foliage and the blooms. Looks like a large plant - did you purchase a division?

Marilyn has gorgeous plants. Some of the cleanest and best-rooted I’ve received (I’ve ordered Phrags and Paphs as well from her). I’m sure it’s something I’ve done on my end. The second one I purchased from her is showing no issues. Are you using MSU on yours? I thought I read that on one of your posts.

Love the bonsai pots with it - was planning on replanting into one when it’s done blooming.

I did not get a division this time, though I’ve had two from her in the past. It’s the ‘Windy Hill’ x ‘Oaxaca’ of course. The other two I got from Sam. The larger of the two is the ‘April Fool’s’ but he sent me a free smaller one that is the same as the one from Marilyn but I just stuck both in the same pot. Both of those had some shipping damage but recovered fine.

Yes, I use MSU for tap (I use fridge filtered water) and Kelpak from Ray is my latest thing to try…

Speaking of that, @Ray since I put everything I own in clear pots again and started the Kelpak a month ago, everything has new root growth. Thanks for the tip!

 

[Skoester]

FWIW, Since moving my plants out of a greenhouse into seasonal outdoors/windowsill culture, I feed once a week with about a 100 ppm N solution, no matter how it’s being grown - S/H, traditional LECA/cubes, or mounted. If it needs water more than that, water is all it gets in between.

Good to know, Ray. That certainly makes the feeding more ideal for each plant- the only reason I’ve been using the weaker solution is because I’ve heard some on the forum caution use of plain R/O water. While I’ve used it occasionally to flush the plants, I’ve been concerned about using it as frequently as would be needed for some of my plants that require frequent watering. I’m assuming your using R/O for all waterings?

 

[Skoester]

I did not get a division this time, though I’ve had two from her in the past. It’s the ‘Windy Hill’ x ‘Oaxaca’ of course. The other two I got from Sam. The larger of the two is the ‘April Fool’s’ but he sent me a free smaller one that is the same as the one from Marilyn but I just stuck both in the same pot. Both of those had some shipping damage but recovered fine.

Yes, I use MSU for tap (I use fridge filtered water) and Kelpak from Ray is my latest thing to try…

Speaking of that, @Ray since I put everything I own in clear pots again and started the Kelpak a month ago, everything has new root growth. Thanks for the tip!

Ah, now the size of your planting makes more sense. Didn’t realize it was three plants together. I will probably plant both cultivars I received from Marilyn together as well.

Yes, love the Kelpak. Been using it on all my new plants and then monthly. I grow most of my plants in Rand’s Aircone pots mostly because of a fear of over/under watering but also because I really enjoy being able to check for new root growth. It’s the simple pleasures

 

[Silverwhisp]

I don’t think so. The weather was still fairly cool when they were delivered and there were no signs of damage - the plants were beautiful and in great condition - came from Marilyn at Windy Hill. I felt sure it was something I had done incorrectly. What had me stumped, besides the fact that not all leaves were affected, was that the other mexipedium, receiving the same care, shows no issues.

Have you asked Marilyn for her opinion?

 

[Ray]

Good to know, Ray. That certainly makes the feeding more ideal for each plant- the only reason I’ve been using the weaker solution is because I’ve heard some on the forum caution use of plain R/O water. While I’ve used it occasionally to flush the plants, I’ve been concerned about using it as frequently as would be needed for some of my plants that require frequent watering. I’m assuming your using R/O for all waterings?

The "word on the street" is that using straight RO or distilled water "sucks" nutrients out of the plants, which is unadulterated BS. What it DOES do is contribute essentially nothing to the plant except water, meaning that you need to apply a complete fertilizer, including magnesium and calcium.

I do have an RO system, but more often than not, I use my tap water which is quite pure to start with.

 

[Skoester]

Have you asked Marilyn for her opinion?

No, not yet. I just recently discovered her through this forum and didn’t want her to think I was going to pester her with a question every time one of her plants developed a brown leaf - plus I feel like a poor custodian of her hard work. Thought I’d check here first to see if it was something obvious before asking her. She’s currently pulling another order for me though, so I’ll see what her thoughts are. As many years as she’s grown Mexipediums she’s probably seen it all.

 

[eds]

The "word on the street" is that using straight RO or distilled water "sucks" nutrients out of the plants, which is unadulterated BS.

Similar things are said about using pure RO in aquaria and it is similar rubbish! I have used pure RO in soft water set ups with fish and plants that are from very soft water habitats and they love it.