Fertilizer Question...

Slippertalk Orchid Forum

Help Support Slippertalk Orchid Forum:

Joined
Dec 10, 2018
Messages
213
Reaction score
114
Location
Portland, Oregon
This is a silly question, but the more I think about it, the more I start questioning myself. I always use this fertilizer, and have been using it 1/4 strength and use it every watering along with a monthly flush. What I keep questioning and psyching myself out is that if it's specifically for orchids, why don't they (or do they?) make it usable for every watering right off the bat?
 
Last edited:

Ray

Orchid Iconoclast
Staff member
Moderator
Supporting Member
Joined
Jun 9, 2006
Messages
4,087
Reaction score
904
Location
Oak Island NC
That formula is not made specifically for orchids, just labeled that way and endorsed by the AOS upon receipt of financial compensation.

ALL fertilizers are made for "every watering right off the bat". It's the concentration and frequency of application that need to be controlled together. My experience has taught me that my plants do well when I apply 75-125 ppm N weekly, summing the number of applications. By that I mean that I divide that average (100) by the number of times I'll be feeding them, and the result is the concentration of fertilizer to be applied each time, knowing that rounding up or down for convenience will still keep me in that range.

If you divide 8 by the %N on the fertilizer label, the result is the teaspoons/gallon for 100 ppm N - right in the middle of that range. If you prefer metric calculations, 10.4/%N gives you ml/L. [corrected from my original, erroneous 9.2]

That is a 20-20-20 blend, of which 9.6% of the nitrogen is nitrate and ammonium salts, while 10.4% is urea. From a practical standpoint, the plant won't use much of the urea, so I would consider it a 10-20-20 for dosing purposes. 8/10=0.8, so if I was using that, I'd use about 3/4 tsp/gallon once a week, 3/8 for twice a week application, etc. Their recommendation of 1 teaspoon every 10-14 days is right in line with that.
 
Last edited:
Joined
Dec 10, 2018
Messages
213
Reaction score
114
Location
Portland, Oregon
That formula is not made specifically for orchids, just labeled that way and endorsed by the AOS upon receipt of financial compensation.

ALL fertilizers are made for "every watering right off the bat". It's the concentration and frequency of application that need to be controlled together. My experience has taught me that my plants do well when I apply 75-125 ppm N weekly, summing the number of applications. By that I mean that I divide that average (100) by the number of times I'll be feeding them, and the result is the concentration of fertilizer to be applied each time, knowing that rounding up or down for convenience will still keep me in that range.

If you divide 8 by the %N on the fertilizer label, the result is the teaspoons/gallon for 100 ppm N - right in the middle of that range. If you prefer metric calculations, 9.2/%N gives you ml/L.

That is a 20-20-20 blend, of which 9.6% of the nitrogen is nitrate and ammonium salts, while 10.4% is urea. From a practical standpoint, the plant won't use much of the urea, so I would consider it a 10-20-20 for dosing purposes. 8/10=0.8, so if I was using that, I'd use about 3/4 tsp/gallon once a week, 3/8 for twice a week application, etc. Their recommendation of 1 teaspoon every 10-14 days is right in line with that.
Interesting tid bit about the endorsement, had no clue.

Thanks so much for the breakdown, I really had to clue about the tsp/gal formula for 100 ppm N, that's very useful! Since I have very little left, I've purchased some K-Lite so I'm looking forward to using that from now on
 

LO69

ST Supporter
Supporting Member
Joined
Nov 17, 2021
Messages
318
Reaction score
392
I get the chance to post here a question about fertilizer duration.
I have more than 15 years old 15 kg. 20/20/20 and 30/10/10 (Peters) bags that I did not properly care for as I let humidity going in and resulted in a
hard block.
Is still the content good to be used?
Thanks!
 

Ray

Orchid Iconoclast
Staff member
Moderator
Supporting Member
Joined
Jun 9, 2006
Messages
4,087
Reaction score
904
Location
Oak Island NC
Ray, if one’s powder has absorbed water, (thinking here of my Cal-Mag 15-5-15 granules; a sloppy mess) how much does that water weight skew the outcome?
There's no way to know just how much water it absorbed, which is why a volume estimate, while not as precise, is the best you'll be able to do.
If you prefer metric calculations, 9.2/%N gives you ml/L. - Ray are you sure that per litre?
My mistake - There are 4.928 ml/tsp and 3.785 L/gal, so the dimension will be 4.928/3.785=1.3 times the tsp/gal figure, so 8 x 1.3 = 10.4 ml/L (for some reason, I have 9.2 stuck in my head...)
I get the chance to post here a question about fertilizer duration.
I have more than 15 years old 15 kg. 20/20/20 and 30/10/10 (Peters) bags that I did not properly care for as I let humidity going in and resulted in a
hard block.
Is still the content good to be used?
Thanks!
Yes, the contents are still fine. If they contains calcium and magnesium nitrates, that will likely be reacted to relatively insoluble gypsum, but otherwise, other than being an ugly mess, there should be no issues.
 

LO69

ST Supporter
Supporting Member
Joined
Nov 17, 2021
Messages
318
Reaction score
392
There's no way to know just how much water it absorbed, which is why a volume estimate, while not as precise, is the best you'll be able to do.
My mistake - There are 4.928 ml/tsp and 3.785 L/gal, so the dimension will be 4.928/3.785=1.3 times the tsp/gal figure, so 8 x 1.3 = 10.4 ml/L (for some reason, I have 9.2 stuck in my head...)
Yes, the contents are still fine. If they contains calcium and magnesium nitrates, that will likely be reacted to relatively insoluble gypsum, but otherwise, other than being an ugly mess, there should be no issues.
Sure no calcium into my standard Peters fertilizer, and very little Mg if any.
 

gego

ST Supporter
Supporting Member
Joined
Mar 19, 2015
Messages
2,160
Reaction score
226
Location
NVa
That formula is not made specifically for orchids, just labeled that way and endorsed by the AOS upon receipt of financial compensation.

ALL fertilizers are made for "every watering right off the bat". It's the concentration and frequency of application that need to be controlled together. My experience has taught me that my plants do well when I apply 75-125 ppm N weekly, summing the number of applications. By that I mean that I divide that average (100) by the number of times I'll be feeding them, and the result is the concentration of fertilizer to be applied each time, knowing that rounding up or down for convenience will still keep me in that range.

If you divide 8 by the %N on the fertilizer label, the result is the teaspoons/gallon for 100 ppm N - right in the middle of that range. If you prefer metric calculations, 10.4/%N gives you ml/L. [corrected from my original, erroneous 9.2]

That is a 20-20-20 blend, of which 9.6% of the nitrogen is nitrate and ammonium salts, while 10.4% is urea. From a practical standpoint, the plant won't use much of the urea, so I would consider it a 10-20-20 for dosing purposes. 8/10=0.8, so if I was using that, I'd use about 3/4 tsp/gallon once a week, 3/8 for twice a week application, etc. Their recommendation of 1 teaspoon every 10-14 days is right in line with that.
I would not discount urea, it is 80% of my N feeding and my plants are growing. And I would not discount 20-20-20 formulation either. Just be mindful of what water you use to mix it with for pH, CA, mag and micros. Check the iron, it might tilt the balance between other micros, Mn and Zn. Just sharing my mistakes. Also check for chloride formulation in the mix. If your using tap, you may have more than enough of it already. Just my 2 cents.
 

Ozpaph

Well-Known Member
Joined
Jan 15, 2011
Messages
18,450
Reaction score
1,358
Location
Brisbane, Australia
Gego, that doesnt necessarily mean that your plants are utilising urea. It could be the other 20% N is enough (depending on how much/concentration you use).

chrome-extension://efaidnbmnnnibpcajpcglclefindmkaj/https://staugorchidsociety.org/PDF/OrchidMyths-UreabySueBottom.pdf
 

gego

ST Supporter
Supporting Member
Joined
Mar 19, 2015
Messages
2,160
Reaction score
226
Location
NVa
Gego, that doesnt necessarily mean that your plants are utilising urea. It could be the other 20% N is enough (depending on how much/concentration you use).

chrome-extension://efaidnbmnnnibpcajpcglclefindmkaj/https://staugorchidsociety.org/PDF/OrchidMyths-UreabySueBottom.pdf
I dont really think so. My N is only 100 - 125 ppm. 20% of that is nothing compared to the growth of the plant. I can see this in fast growing vandas, phals and multis.
But I don't want to get to this exchange, we just need to be careful sharing opinions that may not help others and may start throwing away their fertilizers. Mine maybe just an opinion but based on experienced. Anyways, I'm just sharing. Also, I buy quality more expensive urea, then soak it in liquid at least for a day before mixing it with PKs.
 

Ray

Orchid Iconoclast
Staff member
Moderator
Supporting Member
Joined
Jun 9, 2006
Messages
4,087
Reaction score
904
Location
Oak Island NC
Orchids can utilize nitrates, ammoniums, and urea. They just don't do so at the same rates. Root exposure favors uptake by the first two, while foliar exposure favors the urea, but the plant gets some of each, no matter what.

Plus we cannot forget that urea decomposes both by hydrolysis and bacterial breakdown.
 

denisewh

Active Member
Joined
Aug 4, 2021
Messages
30
Reaction score
4
This is a silly question, but the more I think about it, the more I start questioning myself. I always use this fertilizer, and have been using it 1/4 strength and use it every watering along with a monthly flush. What I keep questioning and psyching myself out is that if it's specifically for orchids, why don't they (or do they?) make it usable for every watering right off the bat?
That is what I do but I am also considering a calcium, magnesium, seaweed combination for one of the waterings each month. Does anyone else use extra of these for their phrags? I'm not real smart figuring fertilizers and use Norm's Nutrients in general for all my orchids.
 

gego

ST Supporter
Supporting Member
Joined
Mar 19, 2015
Messages
2,160
Reaction score
226
Location
NVa
Orchids can utilize nitrates, ammoniums, and urea. They just don't do so at the same rates. Root exposure favors uptake by the first two, while foliar exposure favors the urea, but the plant gets some of each, no matter what.

Plus we cannot forget that urea decomposes both by hydrolysis and bacterial breakdown.
Exactly. And I think when urea breaks down being non polar, first it brings the pH down a bit and then brings it up to where it started. With nitrates and ammoniums, at some point you have to bring that pH back and thats a guessing game. And since it's not salt nor a mix of another element, it is easy to add without affecting the balance and the ppm of the liquid fert. It is a good combination of calcium bicarbonate in tap water.
 

Carmella.carey

Well-Known Member
Joined
Mar 6, 2022
Messages
327
Reaction score
190
The only water soluble feeds I would use for every watering (except the flushes) would be K-lite MSU and the Oceans rain mix. I have used all three ( not all together😂) for every watering on paphs phals and catts.
Patrick
 

Ray

Orchid Iconoclast
Staff member
Moderator
Supporting Member
Joined
Jun 9, 2006
Messages
4,087
Reaction score
904
Location
Oak Island NC
That is what I do but I am also considering a calcium, magnesium, seaweed combination for one of the waterings each month. Does anyone else use extra of these for their phrags? I'm not real smart figuring fertilizers and use Norm's Nutrients in general for all my orchids.
All plants need a calcium supply when in active growth, as previously absorbed calcium is not easily transferred to new tissue from old, as is the case for other nutrients. A once-a-month supplement isn’t going to do that adequately, but your water supply might already have plenty. My regular use of K-Lite ensures that they’ll always have it available.

A monthly magnesium supplement cannot hurt.

The value of adding a seaweed supplement depends entirely on the brand used, as many are nothing more than vegetable-based fertilizers that add little to a normal feeding regimen. Take a look at Comparing Seaweed Extracts.
 

denisewh

Active Member
Joined
Aug 4, 2021
Messages
30
Reaction score
4
All plants need a calcium supply when in active growth, as previously absorbed calcium is not easily transferred to new tissue from old, as is the case for other nutrients. A once-a-month supplement isn’t going to do that adequately, but your water supply might already have plenty. My regular use of K-Lite ensures that they’ll always have it available.

A monthly magnesium supplement cannot hurt.

The value of adding a seaweed supplement depends entirely on the brand used, as many are nothing more than vegetable-based fertilizers that add little to a normal feeding regimen. Take a look at Comparing Seaweed Extracts.
Thanks. I have the Cal Mag here but also a product from Palmer Orchids called Palmer Orchids Special a cal, mag and seaweed extract only product that are granules I am thinking the later could be used in small amounts for each watering. Mine are definitelly going through the growing stage right now. Goal is to learn exactly what I need for Paphs and phrags as I have light shelves with only those two so they are not mixed in with the entire group of orchids I have. I will take a look at comparison of seaweed extracts, thanks. Can paphs and phrags use the same fertilizing dosage for each watering? I use saucers with gravel under phrags and keep roots on Paphs damp all the time. I would love to perfect my care of the slipper orchids as they are by far my favorites but also need to look into their temperature requirements as well.
 

Ray

Orchid Iconoclast
Staff member
Moderator
Supporting Member
Joined
Jun 9, 2006
Messages
4,087
Reaction score
904
Location
Oak Island NC
A granulated seaweed extract is nothing more than a fertilizer, so don't overdo it. The processing has degraded any of the other, potentially useful ingredients.

As far as I'm concerned, all my plants get the same feeding regimen. Of course, I do sometimes refer to myself as an "equal opportunity abuser" of plants.

I have most success with the following: A Regimen for Growing Excellent Plants
 
Top