Fertilizer Change During Flower Spike

[Ray]

Originally Posted by Bloomer001

I'm going to try a seaweed extract next Spring through Fall when root development starts again (KelpMax, Clean Kelp, etc.).

Some kelp extracts are designed more to stimulate root growth. Others, like Kelpak (formerly retailed as KelpMax) is more of a "biostimulant IV" that affects everything.

[I want the plant to focus on spiking and budding now, so going to forgo hormones that trigger root production for the moment.

Kelpak is not a hormone root stimulant.

I like your Ca and Mg formulas - I will experiment with these.

If you are using NYC water, you must supplement them.

And I will get a pH tester to take a closer look at that, and treat water to get an optimum pH level (likely pH down).

The pH of your applied solutions have little-, to no effect on the rhizosphere pH. Read: Orchids and pH

Based on my limited experiments, I think higher nitrogen is key for leaf, root & spike growth. Everytime I dosed the Miracle Grow with 24 nitrogen the leaves, roots & spikes took off (it is very noticeable.) The MSU pellet formula that I use has less nitrogen at 13 N. So that tells me the higher N in the Miracle Grow is making things happen (at least for leaves, roots and spikes.) I don't know if high N is as critical for budding and flowers. (Ray's website says it is.)

You're making several mistakes here.

1) Don't equate formula with concentration. One teaspoon of a 30-10-10 formula and 2 teaspoons of a 15-5-5 formula provide the identical level of nutrition and the same ratios.

Nitrogen is, by far, the most important nutrient. About 99% of the dry content of a plant is C, O, H, (from air and water) and N (from fertilizer), about 1% is P, K, Mg, Ca, and S, combined, and the remaining fraction of a percent is everything else, so if you control your feeding by nitrogen, adjusting based upon the formulas' content, you're fine.

2)No where does my website say higher nitrogen is critical for budding and flowers. The right level is important. All the mineral elements are needed for the plant to grow all tissues. The fact that some tissues have differing mineral concentrations to others does not mean that adding those will specifically cause the plant to grow those tissues.

Plants basically have three priorities - maintenance (staying alive), adding tissue (growth), and reproduction (flowering). Through the course of water, air, mineral and photon uptake, they undertake a variety of chemical processes that create and array of chemical reserves. Your cultural conditions greatly determine the rates of creation and consumption. Poor and the plant cannot create enough to sustain itself. "Enough" and it may stay alive but not grow. "Additional" provides more opportunities.

First and foremost, they will apply those reserves to staying alive. If the production of the reserves exceed the maintenance demand, the plant will expend them on adding tissue. If the production fare exceeds the total demand, it may expend them on attempting reproduction. What the plant does is not determined by the mineral ratios to which it is exposed, they are controlled by hormonal signals and triggers that are significantly culture dependent.

Focus on culture and wetering, not nutrient ratios. For any plant to gain one pound in mass, it must chemically process about 5 grams of fertilizer and 200 pounds of water. As most plants lose 95% or more of their absorbed water through transpiration suggests that the amount of water absorbed for that pound need to be on the order of 4000 pounds to the 5 grams of nutrients.

[Bloomer001]

I did some more research and I was definitely wrong about adding more Phosphorous during spiking, bulbing and/or flowering. See Exs. 1-2. University level studies show that the correct levels of nitrogen are key to all phases of growth - including flowering. See Ex. 3. And that in order to affect flowering, these levels need to be in the plant during the growing season - well before spiking. Id.

As you suggest, Calcium and Magnesium are critical for all phases of growth. This is well supported by the literature. See Ex. 5. In addition, articles suggest that it may be worth considering water and substrate characteristics to dial in fert ratios. See Exs. 6-7. As you suggest, it's notable that pH in the substrate (rhizosphere pH) can be very different than the pH used when watering. The type of substrate affects pH greatly, e.g. moss makes the substrate very acidic. See Ex. 7. So I need to measure the pH in the pot, before the watering can. I can then dial things in.

I'm interested in the K-Lite fert you offer on your site. The nitrogen ratios seem to be supported by the science and research articles. I will also look into the Kelpak biostimulant on your site. I may end up getting the Optimum Growth Package you offer.

Thank you for your thoughtful comments and suggestions.

[MateoinLosAngeles]

Most of the evidence shows no benefit to changing fertilizer concentrations during blooms/vegetative growth, etc.

The consensus is to fertilize weakly and often, especially for Phals, which makes sense. Calcium is important, but you don't need a concentration higher than what comes in the MSU. Besides, you could run into mixing/precipitation issues. I personally use K-Lite and fertilize at 25 ppm N.

I fertilize with every watering in the spring and fall; during winter, I mostly water with plain water, and in summer, I fertilize at every other watering or less. During winter I may mix some RO water with tap water which adds calcium carbonate.

Calcium benefits all orchids, but it's not particularly essential for Phals; rather, orchids that are more frequently lithophytic seem to appreciate it more. Too much calcium could make the medium too alkaline, and Phalaenopsis seem to prefer more acidic conditions; some growers say they experience improved growth when lowering the pH of their fertilized water, although I haven't tried it myself.

I add slow-release dolomite lime or marble chips to Oncidiums, Paphs, and European terrestrials. They all seem to benefit from that, even need it to put out strong growth. However, I don't necessarily supplement it (beyond what's in K-Lite) for any other plant and none have shown signs of deficiency.

[buzzlightyear]

Originally Posted by Bloomer001

I did some more research and I was definitely wrong about adding more Phosphorous during spiking, bulbing and/or flowering.

I agree.

However when it comes to the other nutrients it is far harder to get the right answer. Ray's website is one opinion. But it seems to be very popular on this forum. In fact I'd go so far as to say it seems to be the only valid opinion on this forum when it comes to growing orchids.

I've already mentioned I do not follow Ray's methods.

According to my research nitrogen is indeed the most important nutrient, without nitrogen, plants will not survive. So that makes it important.
What this does not mean is that it need to be fed in the highest quantity at all times. That is not what it means...

That is what I disagree with a lot.

In fact according to my research too much nitrogen will cause stem rot and fusarium. Excessive nitrogen locks out calcium and potassium. This can cause calcium deficiencies.

So what is excessive? Well in order to determine that you compare how much potassium and how much calcium and how much nitrogen you are feeding.

So if you are using a balanced 20-20-20 fertilizer then you are not feeding excessive N because they are all the same strength. If one uses tap water it will contain enough calcium. Rain water will need added calcium added.

So what is excessive? Well it's kind of self explanatory and highly controversial on here based on my research. The opposite of balanced basically. But I know I am in the minority here and it would be like turning up to a republican rally wearing a democrat shirt. I get it. But reseaching these things is important to me. Everyone can argue that nitogen is important and I am not disputing that but it shoud be used in the right quantity.

According to my research, it should not be excessive.

Here is a good scientific article I have been following myself:

Potassium_Nutrition_Affects_Phalaenopsis_Growth_an d_Flowering

[MateoinLosAngeles]

Originally Posted by buzzlightyear

So if you are using a balanced 20-20-20 fertilizer then you are not feeding excessive N because they are all the same strength. If one uses tap water it will contain enough calcium. Rain water will need added calcium added.

I think you're confusing fertilizer composition with solution concentrations. If you feed 1/2 tsp/gal of a 20-20-20 fertilizer, you would give the same amount of nitrogen as if you fed 1.5 tsp/gal of Orchid Pro (7-8-6). So using a fertilizer with a higher N number doesn't mean you're feeding more nitrogen unless, of course, you also increase the amount in solution.

This is to say that the fertilizer you use doesn't really matter, what mattes is how much of it you put in your feeding solution. I personally choose my fertilizer based on how it changes the pH of the water and its ability to dissolve.

To clarify, the reasoning for lower K feeding is based on research showing orchids may have an adaptation to "hog on to K" which allows them to survive in environments with low potassium availability, yet showing sufficient levels in tissue analysis. Thus the reduction of K feeding is aimed to avoid cumulative potassium toxicity over several years, not based on the results of one season.

As you pointed out, excess N seems to be correlated with higher incidence of rot. Thus why I personally fertilize at only 25 ppm N per watering.

[Bloomer001]

I'm seeing the plants react to higher N. As I increase the dose, more growth is apparent (roots, leaves & buds.) I have them under the lights 12 hrs a day, so I don't reduce fertilizer in the winter as others do grown under natural light. However, temperature needs to be taken into account as this greatly impacts plant metabolism and growth rate. I'm feeding about 125 mg N weekly in 2 doses. I think this is the max they can handle without adverse affects -- and I have worked them up to this level (I would not recommend going from zero to high levels of N as it may harm them.) After they flower I will greatly reduce fertilizing, and will do a lot of flush waterings with no ferts.

I suspect the Kelpack may be helping nutrient absorption. In the spring, I will slowly restart ferts and likely increase the N dose in the Kelpack treated plants to 150 mg weekly, but this will alter the experiment. I have no doubt N is the primary supplement to increase growth -- in the correct dose based on growing conditions and the health of the plants.

I add a few bark chips to the topsoil once a month. This keeps the soil slightly acidic.

[buzzlightyear]

That's some good looking phals.

I find it interesting that the miracle grow caused the plants to branch more.

I know it can be tempting to think it is the nitrogen but fertilizing is a complicated subject and it could be a variety of reasons. I personally believe you can do better still too. Just based on the research, that's all.

I also know the consensus on this board is that high nitrogen is the most beneficial. I don't really know why because the science says otherwise. I haven't found any evidence to confirm a higher nitrogen content is better for orchids. I have read many time on this forum that that is what the science says.

But if one reads the article I posted and another one I posted but never posted it seems, one will see the latest evidence is strongly in favor or a more tailored mix.

But you are proving you get great results with a bog standard miracle grow fertilizer.

I know plenty of growers that use different formulations and the more evidence we gather as growers the better. So it bugs me that is not done more, instead everyone gets told to just do it one way.

Even the dyna grow which I believe has too much phosphorous gives great blooms.

Anyway I will try the article again. I try to grow my orchids based on the latest information we have.

PHALAENOPSIS MINERAL NUTRITION

I don't understand why there is a reluctance to accept it more.

I know its hardly the most important aspect of orchid growing and will probably not even cause any orchids to not die or anything like that. I just do not like going along with a belief that is just that and there is evidence to suggest it isn't even accurate. If people still want to believe it that is fine

I belive everyone should be presented all the facts and make up their own mind even if I know it is impossible to change someone's opinion online if they have already formed an opinion. This is actually a fascinating phenomena. People go like "who is this guy telling me I'm wrong" when all they are trying to do is point out a new discovery instead. It never gets seen that way.

Mayeb a new grower who has not formed an opinion yet can become the next orchid grower mozart or picasso. Who knows.

[estación seca]

Many people here have posted many times what are good ranges of nitrogen concentration in the applied solution for Phalaenopsis orchids. These recommendations are not considered high nitrogen.

[Ray]

Originally Posted by Bloomer001

I'm feeding about 125 mg N weekly in 2 doses.

May I ask how you are determining the mass you're applying?

Don't forget that "exposure time", extent of root growth, and velamen volume are other important factors.

Starting at the extreme of a bare-root vanda in a slat basket: their "exposure time" is only during the actual application of the fertilizer solution, and the amount that can be absorbed is limited to the volume of the velamen layer on the roots.

Now go to a cattleya in a pot of coarse bark. The exposure time is the time of application, just like the vanda, but is also extended by the time that roots are in direct contact with solution held within the medium. Bark doesn't wick very well, so once those "contact points" have been extracted, that period ends. The total volume of velamen is probably reduced compared to the vanda, so that reduces the immediate uptake, even while the exposure time is extended.

Then there's an oncidium in sphagnum - the medium holds and wicks the fertilizer solution well, and the plant has lots an lots of much finer roots (and greater overall surface-to-volume ratio) to make contact with it, but the velamen is relatively thin. If we assume the velamen-to-vasculum transfer rate is similar for the three, it seems likely the oncidium will take up more of what is applied.

[alecStewart1]

Originally Posted by MateoinLosAngeles

.
I fertilize with every watering in the spring and fall; during winter, I mostly water with plain water, and in summer, I fertilize at every other watering or less. During winter I may mix some RO water with tap water which adds calcium carbonate.

I know there's more advanced discussion going on here, and I'm not the most experienced, but sometimes it's not wrong to keep it simple.

What MateoinLosAngeles said is basically what I've concluded for my orchid culture.
Pretty much all of the orchids I have are ones that want to be wet and then left alone to let their medium dry. In winter, watering less is necessary because you could say orchids are like people; who likes being wet and cold?

As for fertilizing, since I mostly have Vandaceous orchids and some Dendrobiums that are in sphagnum moss, so come spring time I fertilize every other watering to avoid unwanted mineral build up.
For the orchids in bark or looser mediums that won't hold on to water like moss does, I'll water every watering.

The above is in line with what Ray mentioned.

The only other thing I've seen is "if the orchid is growing, you should give it fertilizer." So an example would be Neos, they're just chilling for the winter and not growing so I just water them with plain water. My Phal on the other hand is growing new leaves and roots, so I fertilize it. I'll just use K-Lite for fertilizer at the recommended amount, maybe I mix in some Kelpak or Quantum Total from time to time or some calcium supplement if need be.

I think the only times I've seen people need to add more of something like nitrogen or calcium or whatever else is when something funky is happening with your plant (bud blast, abnormally stunted growth, etc.) and the rest of the culture is fine, or if you have a plant that wants more calcium than the others or something to that extent.

Maybe there's a super optimized method of doing things, but I don't grow anything professionally and have so far haven't had many problems following the basic advice, so why give myself more things to think about than I already do?

Probably wasn't the simplest explanation, but...yea.