Here we are again...Let's talk Rot

[emmajs243]

Excellent!! So this Toshie Aoki just keeps busting out growths. When she arrived she had tons of white new roots with green tips growing but they were all already a couple of inches long so i didn't know if it would be good to repot at this point or not. Then yesterday I noticed she is busting out more new root tips too.

Do we think I'm too late to repot her or since she still has new roots coming in still ok and just need to be very careful? I just wanted to get her into a nice basket with an airier mix then what she has now. Although, her bark is in good condition now it's just not quite as airy as what I like especially considering the C. dowiana background liking to dry quick.

And for fertilizer...since we last spoke on fertilizing, i have been trying to do the fertilizing equivalent PPMs of N as your K-lite instructions that you sent me with my last order! Thank you for that by the way...So helpful! So I've been wanting to 100% get on every other day or daily...as needed at the 20 ppm range but this doesn't always happen for various reasons but at the absolute least I'm doing weekly at the 50 ppm range.

While I got knowledgeable people here...I've been looking into calcium/magnesium/iron deficiencies in orchids. Many people mentioned this helped their C. dowianas prevent rot quite a bit. Because I'm on a well, the well water MSU formula doesn't have the same calcium/magnesium amounts as the regular MSU. But I also had read that hard water can affect whether or not the calcium can actually be absorbed by the orchid. Anyone know anything about this? I have hard water and am partially considering swapping to just watering with RO so I really have full control and knowledge of what they are and are not getting...

[Subrosa]

I have 3 individual dowiana seedlings, 2 sibs of an aurea selfing and a var rosita. I group all of my plants by the minimum temperatures I allow them to see outdoors, in 10° increments. The dowiana are in the 60° group, because due to my indoor winter conditions there is no 70° group. All three plants sat practically touching all season, and came in together after experiencing several nights in the low 60s. The rosita and one of the aurea took this much better the other aurea. A growth it was finishing up stalled and never really recovered, although it has started a new growth. The other 2 finished up the growths they were working on, and the rosita rather than resting then developed a second lead and matured 2 new growths indoors under the lights over the winter. Both of those have new growths as well. The point being that even within the species there's considerable individual variation in temperature tolerance.

[Ray]

As to the calcium and magnesium; both are essential nutrient minerals, but their mobility in plants is entirely different.

Calcium must be provided continuously to growing plants because - unlike most other minerals - once it has been absorbed and incorporated into plant tissues, it cannot be easily moved from there to the newly-forming ones. If a plant is calcium-deficient, the tips of new growths will die and blacken, appearing much like rot, which, of course, will happen later to the dead tissue. (Your losses were NOT from the tips of the growths; they looked to be quite healthy until they rotted off at their bases.)

Before you go crazy worrying about calcium (or any nutrient, for that matter), have your well water tested so you KNOW what you're dealing with. The J. R. Peters Lab is one of the best places to have that done. $40 well spent.

The MSU WW formula does have some calcium and magnesium in it, just not as much as the RO formula or its derivative, K-Lite.

Magnesium deficiencies are quite rare, primarily because it can be easily shared among all plant tissues. A deficiency usually shows up as pale leaf color known not to be caused by excess sunlight. If you have a known deficiency, throwing a teaspoon-per-gallon of Epsom Salts in your watering regimen monthly will fix it.

I am now stepping back and offering "fatherly" advice: It appears you are trying to find nutrient-based explanations for the issues you are having. Working in a lab, that is actually understandable - I spent my career in the chemical industry and I used to do the very same thing! However, it is very unlikely that any of the issues are nutrient-related, and throwing chemicals at them will not fix any shortcomings in the rest of your culture. Mask them a bit, possibly, but not cure them.

You seem to have jumped into orchid growing with a great deal of enthusiasm, and are trying to learn as much as you can to improve your growing, but I suggest that you slow down and be keenly observant of the basics - air/water/humidity/temperature/light - so you can get those right. Nutrients and additives are part of the "fine tuning" of your growing abilities.

[emmajs243]

Thank you Ray! I will always take some fatherly advice!! I knew this wasn't due to a calcium deficiency, as you said. I honestly haven't thought about nutrient deficiencies period until this week...that's only because when you search Rot in C. dowiana it's one of the main things always mentioned so it led me to investigate which led me to people discussing the addition of extra calcium has seemed to help reduce rot in their plants.
I am still trying to worrying about lights and repotting for crying out loud! And honestly, I just feel like as a beginner, any turn for the worse is due to me...but that mentality was ingrained in me at a very young age when I started riding and competing horses.

I did use to always do that though when I first started riding..me:."do you think maybe it's the bit? Or because he has been off for a few days?" Gruff German coach: "*Rolls eyes* No, the bit is fine. It's because YOU are not riding correctly and clearly communicating what you want, there is no one here to blame but yourself". That has been my riding coach for 17 years now and around the one year mark it was a constant sing song in my head "If your horse isn't listening, there's no one here to blame but yourself. 90% of the time they are just doing what you ask. If they aren't doing what you ask, well then you aren't asking correctly. No matter how much fancy tack you use or try to change, If you don't ride correctly and precisely your will not receive precise results..." I think it still took me until year 2 before I fully believed that statement but 17 years later and I still do and now pass it along to my students too.

The only reason nutrient deficiencies have stayed on my mind is less for my acclimated plants and more so due to a few plants I have recieved in recent orders...like the Catts that came with this Toshie Aoki...they have some purplish tinted markings...Definitely doesn't appear like any disease or infection or anything to necessarily be severely worried about, it's just a tad odd....so a small part of me was wondering if those purpilish markings they came with were a sign of something like that.

Water wise! That is SUPER helpful to know...I called a local water lab to see what a similar water analysis would cost and they quoted me $300. So I had completely given up on getting a water analysis!

I do know the water analysis results for a small section of our county including me...the averages for my precise area, pH is </=7.72. Alkalinity is >300mg/L. Hardness is >300 mg/L. TDS is 500-1000 mg/L.

The averages for this entire section of the county provide: all in (mg/L)
- Ca is 50-90 with 75 average.
- Mg is 20-37 with 30 average.
- Na is 30-80 with 40 average.
- K (potassium) is 5-8 with 6 average.
- HCO3 (bicarbonate) is 205-360 with 310 average.
- SO4 (sulfate) is 70-150 with 100 average
- Cl is 30-50 with 40 average
- F is 0.4-0.95 with 0.65 average.

Basically they said everyone's water is made up of calcium and magnesium as the cations and for anions, the majority (65%) had primarily bicarbonate but there was a good portion(30+%) with primarily chloride+sulfate instead. Then it just goes in to all the metals and nitrate results.

I just have somewhat given up on trying to understand how and what these numbers mean for me and my orchids....at first I thought well it's all calcium magnesium practically so I should be good! Then I found that hardness can cause issues in absorabance so even water with lots of Ca & Mg, that doesn't mean your Orchid is able to absorb it. And I felt like asking someone on here to intrepret my local water analysis results was far too much to ask of anyone!

[aliceinwl]

I’m not sure if this is the case for yours, but I have some temperature tolerant Cattleya that I grow outside. They all having varying degrees of purple tinting due to sun exposure. If you’re growing under high light conditions, I’d expect that what you’re seeing is normal.

Probably not much comfort to you, but I’m learning a lot about Cattleya culture from your posts!

[emmajs243]

Awww Aliceinwl! Thank you! That makes me feel ten million times better actually! I feel the whole, "when it rains it pours" quote definitely applies to orchids! I went quite sometime with no problems and no need to really post....after weeks of constant posting...and I thought sweet! Im figuring it out! Then my seedlings got rot and from there it feels like I've been constantly posting again!! I always feel so bad about constantly posting so It totally does make me feel so much better hearing its actually helping others too!

And Ya. I had heard people mention a "purple tinge" when growing under high light....I just felt like it would show on the top of the plants leaves and what not...where light hits...

I also have been wondering if Cattleyas can naturally have different pigments....my Toshie aoki arrived with this pretty nice, light/medium green color and some purple markings....that one I thought, ah! This must be what people mean when they mention purple due to too much light! Then I went to the next plant and she is a really dark green in comparison to any other Catt I've seen and she has purple on the underside of her leaves too! But I thought if they were dark green it meant they weren't getting enough sunlight which I wouldnt expect coming from Hawaii....and just being in bloom. the third is a medium color but she doesn't have any purple really except through her flower stem/spike...whichever it would be for a Cattleya? So I don't know...would the dark green Catt have the same purple rings if she isn't getting enough light? Unless maybe she just never really becomes the "apple green" no matter how much light...is this even possible though? That's why I was thinking it must not be due to too much light.

But! thank you for telling me that! Today I was thinking how I need to get an address list and send cookies or something out to everyone who constantly comes to the rescue on my orchid posts!

[aliceinwl]

I have four different temperature tolerant Cattleya types growing together outside and they all have different color leaves in terms of shades of green and different degrees of purple. It really seems to vary among plants with different pedigrees. With my Laelia aniceps, the pseudobulbs purple more than the leaves.

[emmajs243]

AhhhHah! Excellent to know! I know...I felt it plausible that they have different pigment colors!

[Ray]

Back to your calcium and magnesium levels, Let's compare to some "created" solutions:

Many feel that both the MSU RO (13-5-15-8Ca-2Mg) and K-Lite (12-1-1-10Ca-3Mg) are excellent fertilizers to use with pure water. By the formulas we know that the contributions of calcium and magnesium are fixed percentage of the nitrogen, so if we assume that 50-75 ppm N per week is good, the MSURO will also bring 8/13 of that, or 30-45 ppm Ca and 2/13 or 7-12 ppm Mg. K-Lite will provide about 38-58 ppm Ca and 12-18 ppm Mg.

Based upon that, I'd guess you have nothing to worry about in regard to those ions.

By contrast, my water here is quite deficient in magnesium. Here is the Peters Lab report, so you can see what they'll provide.

[emmajs243]

Oh Ray! Ok, have to get a water analysis test kit ordered in...That is SO much easier to read then what I expected...I figured it would be about like the one done for the county but THAT is actually in our language and provides the "normal range". Very easy to truly understand!