Feed Me!

[Ray]

Parts-per-million are neither difficult to understand nor use, and in fact, offers the grower a valid way to judge the impact of different formulas.

Nitrogen is, by far, the most significant nutrient we provide to our plants, so controlling that is key. Using different formulas can make it difficult to some, but one can estimate that quite easily: for 25 ppm N, simply divide 2 by the %N on the fertilizer label. So a 16-6-12 would require 2/16=1/8 teaspoon per gallon, while a 30-10-10 would require 2/30=1/15 teaspoon to provide the same amount of nitrogen. (For you metric folks, divide 2.6 by the %N, and the result is ml/L for 25 ppm N.)

Then there's the question of "so how do I know what ppm to use?" That is determined by how frequently you feed.

If you think of the "ppm N" as a parallel to counting calories for our own health, it becomes easier- if you eat three meals a day, you might shoot for 2000-2500 calories total, so you divide that in Tom smaller meals. Experience has shown that most orchids grown in the home do quite well with somewhere between 75 & 125 ppm N weekly. As I feed every time I water, Andy that's can be 3 or 4 times a week in the summer, I go with 25 ppm N. If I only fed once a week, I'd probably go with 100 ppm.

[Orchid Whisperer]

(Somehow double-posted; please see my next post)

[Orchid Whisperer]

Originally Posted by Ray

I don't know about their water supply, but I'd guess it's pure.

If I'm not mistaken, the chemistry of granite, which is variable, is all oxides, making me wonder just how much it adds, if at all, to the nutrition.

Ray, you may remember me posting several years ago aboutva spring in North Georgia with TDS in low double digits (don't remember exactly but I think high 20's ppm). That was sourced in granite. True granite can contribute a little K, probably not much N and P, but maybe some micronutrients. If there is much N and P in the water it likely comes from grassland, forest, or farms in the watershed. Oh, and so-called 'black granite is actually a rock called gabbro, which is calcic, and may provide Ca.

[orchidsarefun]

After speaking to many growers over the years ( with award winning plants ), I've developed a really simple fertilizing regime
- fertilize 1x per month
- alternate fertilizer blends/brands
- use extended release fertilizer like osmocote on plants that Summer vacation outdoors. That and a teaspoon of blood meal and a teaspoon of bone meal 1/2 way through Summer.
- dosage of about 1/2 teaspoon per 2 gal watering can for the roughly 1x per month fertilizer all year round.
This works for me and my plants.

Sent from my LG-H901 using Tapatalk

[bil]

Originally Posted by jkofferdahl

Please don't take offense at this, Bil, but many of us out here grow on windowsills using gallon water bottles and sinks. Measurements like Parts Per Million, then, are meaningless to what we have and what we know. Directions expressed in such terms are certainly easily dealt with by really advanced growers, but the OP of this thread owns three orchids and is wondering about using a very old container of orchid fertilizer. How does he (or I, for that matter, with 40+ years of orchids under my belt) - in other words, amateur growers who are growing orchids for simple pleasure - translate such terms into useful measurements we can use when measuring fertilizer in our kitchen using scoops provided in the fertilizer package?

By the way, I don't have a meter to measure light to my plants, either. I just guess as best as I can.

No offence taken. HOWEVER, the only accurate way to discuss levels is in ppm. If you use Ray's calculator, here
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then you can back calculate to get something that works for you. I use a level quarter teaspoonful = about 1.5 g in 6.5 litres, which is the volume of my sprayer. That gives me about 25 ppm.
If I tell you teaspoonfulls per gallon, we have to work out just how big your teaspoons are, and which gallon we are using.
I have seen someone kill a whole pondfull of fish because they wouldn't use SI units.

Oh yes, a suggestion. If you make it up in solution, to be used over a period of time, have a dark box to put the bottle in. I switched to doing that because the bottle would go bright green quite swiftly and cleaning it was a pain.

[charlesf6]

Miracle Gro is offering 30-10-10?

[Orchid Whisperer]

Originally Posted by charlesf6

Miracle Gro is offering 30-10-10?

Yes. Their 30-10-10 orchid food has been on the market several years.

[Ray]

...and then there are the grandmothers who "never feed" their plants, and the suckers bloom and bloom and bloom...

[charlesf6]

Do I need to go online for 20-20-20?
I tried several stores today. Miracle Gro also offered a set of 10-10-10 spikes.

[u bada]

love the fert talks...

While we're at it...

Was just reading an article on AOS mag back issue about ferts... (coincidently) about urea vs non urea based ferts... (and let me note the article was really about nitrogen if that says anything)...

So things to consider from article:

-urea based nitrogen needs to be broken down by micro organisms in media and roots to ammoniacal nitrogen for nitrogen to be taken up, so if it's an established plant in media like bark/moss/etc, then you're fine, if it's fresh media or mounted, won't help too much

-nitrate based ferts, called non-urea based ferts, have nitrogen then can be taken up immediately, so overall these are better (my thought)

-your water quality makes a difference. If you have low tds, or use r/o water, rain water then using urea based i.e. ammoniacal nitrogen ferts will be too acidic of a reaction to media/roots so you want nitrate based nitrogen (look for urea free fert). If you have hard water, then urea based ferts are ok, and actually aid in lowering ph of water so other mineral uptake is helped.

My own professional work focuses on use of native CA plants and mediterranean plants (that's a broad spectrum of plants but...), and these plants have adapted to low nutrient and low water soils through relationships to micro-organisms, like mycorrhizae... so reading this article highlighted the importance of their presence with orchid growing. It is possible with the variability of growth success with grandmother's that don't use fert and those those that use 8 different kinds and amounting to the same success may have more to do with the presence of mycorrhizae... that being, if a microorganism network isn't as developed then fertilizers would be more needed, if quite developed, then fertilizers would be less needed. This of course relates then to media and how to develop this system, and on and on... I can surmise a lot more from this, but suffice to say a happy full established plant must already have a good system growing with it on it's roots and media, and keeping it fertilized could only help it... but on other hand this supports that a poorly growing plant may already be struggling with issues of poor microorganism development in roots, which explains why in many cases you don't fertilize a sick or struggling plant...

Ok, so me personally I've gotten some MSU fert, both for pure water and for well water (from Ray!), for my plants and as mentioned put a little bit every time i water during the growing season and less so when a plant is resting or whatnot... Before I used fish water from water changes with the various aquariums we have, as well as kelp stuff, and fish emulsion, and it seemed to be enough... I honestly can't tell the biggest difference, but certainly I have more healthy plants, it could also be because I'm more on top of watering than I have been this year (last few yours I was working a helluva lot)

Back to fert types, it's worth investigating the various types available, and knowing your water quality. Miracle go I believe, like many, is a urea based fert.