Hey Tcc,
didn't realize you were still here. How is yours doing?
I've been slowly documenting me changing my fertilizer schedule a little recently but I didn't really feel I had an audience that was interested till now.
So full disclosure there are two things I have changed.
1) I doubled the micro nutrients I was feeding, even a little more Iron on top
2) According to the latest research I concluded that Phalaenopsis benefit from getting fertilized with a bloom feed instead of a grow feed. Something like N-P-K in the ratio of 1-2-2 or 1-2-3
Before that I was feeding with a ratio of 1-0.2-1
I have still not fully decided if it was the added micronutrients, the phosphorus or the potassium that has helped the most.
I initially concluded I needed more phosphorous but I quickly discovered that adding just Phosphorous in turn caused a Potassium deficiency, leaves started randomly turning yellow. So I had to add Potassium too and have seen some great results some orchids, this one included but it is a slow process.
Like I was telling someone else the only way to know for sure is to compare leaf sizes, flowering before and after and see if Phals really do grow better with a bloom formula like 1-2-3. I had little to lose - most of my warm growing phals hadn't flowered in the past 6 months and roots were not growing as well.
But it would be interesting to know what fertilizer you have been using to compare.
If you have been using a balanced fertilizer like 10-10-10 then it would be impossible to be caused by a phosphorus deficiency in your plants. It could still be from a lack of micronutrients but I am still leaning towards the phosphorus making this difference.
It is very very hard to make conclusions on orchids. Like I said me feeding more phosphorus seemed like it fixed one thing yet made even more problems appear so luckily I knew instantly what I was dealing with and how to fix it.
Please don't just go trying something new unless you understand what you are doing.
I worked out precisely how much of each nutrient I had been feeding and how much P and K and micronutrients I had to add.
I came to the following conclusions overall but this is just my formula for this year and everyone has their own preferred formula, Lots use 20-20-20. Some use a special ratio they like. Like mentioned for phals I am for the first time trying 1-2-3.
But my overall observations are as follows:
P should roughly equal Mg
Ca should be roughly twice as high as Mg
K should be 3 times your P value
Then N half the K
Fe should be 1/20th of Ca
But one thing I am seeing as a result is lighter leaves overall. The spots are not developing but leaves are growing much lighter than I am used to.
So it could possibly be that as a result of feeding more P and K the ratio of Nitrogen has been reduced so maybe just a slight maybe I have induced a Nitrogen deficiency but I really doubt it as a Nitrogen deficiency starts from bottom leaves and at the leaf tips generally. Whereas what I am seeing is new growth growing lighter than old growth which I think is a good sign but I do just want to add that as something to keep an eye on long term.
I could have just given a very simple answer but I want to point out how when it comes to fertilizing there are firstly a million different opinions, some people will hate me posting my opinion because they will have a completely different opinion and I don't want to step on any toes but I don't want to keep any of my secrets either.
Some would argue I should wait 10 years before discussing my results as orchids grow so slow and if I haven't tested all possibilities then I could be giving bad advice.
secondy it is very difficult to know for sure the conclusion you make will be the same for another grower.
So I hope that is clear, I have only been using this new formula for roughly 3 months and probably a bit less on this one.
I'm not very good at keeping my secrets for the next 10 years to decide if I can narrow it down more to give a better answer...
But my answer is vague because I cannot say with certainty which of the minor changes I made has ultimately made the biggest difference.
Please let us know what you have been using to fertilize and what ratio it has. If you were using a similar ratio to me then it could be caused by the same thing but if not then that helps too as it means it might be due to micronutrients.
Anyway, I hope this all makes sense and how it might not be the easy fix although it's not difficult either, just work out how much doubling the micronutrients needs adding and/or how much P/K to add.
I use this calculator to help work out what my fertilizer contains and how much to add on top of that
Water Soluble Fertilizer Calculator
PS: What ultimately gave me the push to try what I have mentioned, especially for phals was that the latest fertilizer I am trying says on the label to feed what I am saying. According to Orchid Focus for phalaenopsis you should use their bloom feed all year which has a ratio of 1-1.5-2.5
Just thought I should add that too.
So it's not like I am doing something nobody has tried before. It should reassure people to know it is a formula that millions of people already use if they are following the instruction on the label.
Alternatively if this is all too comlicated like I mentioned just see if you can buy some
Orchid Focus Bloom.
It has all the micronutrients and ratio I am copying basically. So that is the easiest fix if you can find it in your country.
healthy leaf color vs unhealthy (not only caused by lack of light!)
Phalaenopsis cornu-cervi with black spots on leaves
)
Linear Mode
