MSU fertilizer PPM scale

[Ray]

My understanding - gleaned from discussions with folks who actually studied nutrition as part of their plant biology courses - is as follows:

Phosphorus may be a critical nutrient, but not in large quantities, and they have active "pumps" to draw it in (as opposed to equilibrating with the environment, as happens with many nutrients), storing the excess in vacuoles.

Phosphorus being a "Bloom Booster" is either marketing BS used to cover up a flaw in a product, or folks' poor and inaccurate interpretation of the facts:

Dr. O. Wesley Davidson of Rutgers University, understanding that orchids like a more acidic environment than many plants, devised the 30-10-10 formula sold as "Mir-Acid". His assessment was apparently correct, as the plants fed that high-nitrogen formula grew like weeds.

Then, with time, it was noted that those plants grew great, but bloomed reluctantly, if at all. Sooooo.... Inexpensive phosphorus compounds were added to the Mir-Acid formula to "dilute" the nitrogen, and Lo! and Behold!, the plants bloomed well again.

It was the removal of the nitrogen "restraint" that allowed the blooming, not any supposed "boost" by the phosphorus that caused it.

To reiterate: a plant in the peak of health will bloom to its genetic maximum capability. There is nothing you can add nutritionally that can push it beyond that.

Oh, and I do sell fertilizers. (and a bunch of other stuff, too)

[orchids3]

Ray,
I know you do and I buy it. A lot of it is great stuff.
Too bad shipping has gotten so expensive.

[keithrs]

Interesting.....

So, "bloom boosting" fertilizers will do nothing if your plant has all nutritional requirements meet?

I have another question for you Ray.....

Would you mix ever fertilizer to 125PPM N? Being that every fertilizer is make differently.

It seems to me, running that high of a overall TDS with every watering will burn your plants?

I did buy some stuff from you not to long ago......Great service!!!!!

[keithrs]

Its also my understanding that high N fertilizer will make your plant grow fast but the cell structure will be weaker making your plants more prone to infections. Any truth behind this?

[Ray]

Feeding a lot of nitrogen has been shown to produce leggy, and "soft" growth. One grower likened it to feeding kids candy - gives them lost of energy, but has no nutrition to back it up.

FWIW, I have fed my plants at 125 ppm N at every single watering for the last 8 years (+/-), without flushing, and I have never experienced root burn.

[Tony L]

Ray, I grow most of my orchids using the semi-hydro setup you describe so well. Using MSU for well water according to the directions (¾ tsp/gal), I will get 125 ppm nitrogen, but my total tds is around 800. (I start with 80 ppm in my well water). I’m concerned that this is high enough to cause problems, especially for paphs. Some of them and a couple of catts had leaf tip burn. I lowered the amount to ¼ tsp/gal, giving me about 300 ppm, and the new leaves were fine. But I’m concerned that they’re not getting enough nitrogen.

[Ray]

Tony, you jumped into an 8-year old thread here, and my recommendations have changed significantly since then!

After several years of frequent application of the MSU RO formula @ 125 ppm N, I noticed that while my plants grew very well, I just wasn't getting the blooming I should. In discussions with folks well-educated in the field, it was suggested I was overdoing the nitrogen. (In retrospect, if you look at what orchids see in nature, it's VERY frequent watering with very pure water containing almost nothing [analyses have demonstrated a max of 15-20 ppm TDS, almost all of it nitrogen], so it make a lot of sense).

After doing some more research on epiphytic plant biology (and plants in general), I decided to modify my feeding regimen, reducing the nitrogen loading to about 20% of the former, to 25 ppm N. I have been feeding at that concentration, using K-Lite (12-1-1-10Ca-3Mg) for 6 or 7 years now, and after about a year or so of that - watering 3-4 times a week in summer, maybe half that in winter in PA - I saw the blooming significantly improve.

Over the next couple of years, I incorporated monthly doses of KelpMax and Concentric Ag Garden Solution into that, and am constantly amazed how well my collection grows, blooms, and multiplies.

[Tony L]

Thanks, Ray! This confirms my observations, so I’ll stop worrying about the N and keep my solution at a low tds. I’m getting good flowering, but may try the regimen you suggest on some of my collection and see what happens. Thanks!

[estación seca]

Remember ambient conditions need to be ideal before fertilizer becomes a big factor in plant growth. Orchids in less than ideal circumstances - most of us - can't use as much fertilizer as can orchids in nice warm humid growing areas with plenty of light.

It's the same thing with food supplements for athletes. They can't help people who go to the gym to sit and talk.