A Gardeners Forum Forums Gardening Reference Gardening in 2006 Nitrogen, Phosphate & Potash numbers on plant care products (???)

I hope that other people are as confused about the numbers on plant care products as I am... (I mean, I hope I'm not the only one who's confused!) I'd like to get this number business straight in my head, once & for all!

So, I know that the numbers stand for Nitrogen, Phosphate & Potash, but my question is: What, exactly, do those elements/chemicals do for (or to) plants?

I am with you on being clueless Patty. Looking forward to answers on this one. Might actually start using stuff on my plants if i know what it does. Right now I plant them, water them and leave the rest to God.

What you have are known as the mixed or so-called "complete fertilizers". They have the three primary nutrients in varying proportions and strengths, so the 8-4-12 would contain 8% nitrogen, 4% phosphorus, and 12% potassium. The three nutrients are always listed in the same order, to avoid confusion.

Nitrogen is usually associated with leaf and stem growth. Phosphorus stimulates early growth and root formation; plus, it speeds up maturity and is involved in seed production. Potassium has to do with root growth, hardiness, and resistance to disease; as well as the development of flowers, fruit size, and quality.

Regarding your two Ortho rose care products, the one with 12-4-8 is higher in Nitrogen than the other one, so it would be the one to use if you wanted to improve the leaf and stem growth of your rose.

Unfortunately, many people think these "complete fertilizers" are the "miracle cure" their plants need, but the ideal fertilizer would be one that makes up for any deficiency which exists in the soil. It is always best to have your soil tested to see what your soil actually needs, instead of adding any nutrients that already are there in quantities which may be adequate or more than adequate.

Thanks patches for your answer.

I'm one of the confussed ones too.

OK, now you guys have REALLY done it! The more I learn, the more I realize how much I don't know! I HATE when that happens, you know! (I know you're doing this to me on purpose, Cyber-Sis! You're off sounding like a college professor again... but any information you DON'T give me, had better NOT be on the quiz!) :p
You know that I'm no good at math, BUT... those numbers don't add up to 100! Where is the other 76% of what I paid for? Why not just plant stuff right in pots filled with these granules? (I haven't given that much thought, but I don't think I'd try it, cuz nobody else does ...& you'll probably give me a "logical" answer, anyway!)
OK, so Nitrogen sounds like a good thing, so I'll leave that one alone.
So, why put Phosphorus in the rose food at all? My rose bush roots are already there & the plants are obviously already mature... (& I've never heard of a rose bush seed!)

So you are saying "Potassium" for that last number, while all my containers are saying "Potash". (Safe to assume, I assume, that they're the same thing!) You probably don't know this one: WHY do they confuse the issue by coming up with a different word for that? Anyway, Potassium/Potash sounds like another good thing.
I did that today... but I think that's going to be a whole different topic, or I need to have the County Extension office test it for me, because my results, according to the paperwork that came with my kit, shows my veggie garden dirt "deficient" for Phosphorus, "deficient" for Nitrogen & off the chart ridiculous "surplus" for Potassium! I know those can't be right, because last year I had very happy Tomato, Canteloupe, Honeydew melon, Watermelon, Bell Pepper, Pole Beans, Sugar Peas & Basil plants in that garden, & was still harvesting some of those things on Halloween!

(By the way... guess what? If I'd have read everything that came with my Soil Test Kit, I wouldn't have had to start this topic! All the stuff you said was right there!)
So, what's wrong with "more than adequate"? If I have large roses already, why not use the 8-4-12, or the 11-6-11 & get HUGE prize-winners? (Do I see one of those "more is less" answers coming?)

Another thing, maybe just a bit off topic, but not really... Where does Epsom Salts come into this? (I mean, besides when you're stiff & sore from playing in the dirt & you need it in you bath water!) Right next door here, there's a topic about Epsom Salts, with a link to gardening uses. I looked on my Epsom Salts carton, & there are no numbers there! (If there were, which one would it be?) Do I need to use it?

You know, this whole thing about plant food, fertilizers & boosters brings to my mind the issues I dealt with when I raised a lot of chickens, & sold eggs & baby chicks... I refused to use lights to trick my hens into double egg production, & was careful not to feed them chemically enhanced feed, to achieve more or "better" eggs, because (1) I didn't want chemicals in my food, or (2) messing up baby chick development, & (3) I didn't want to burn the hens out before their time. It's almost sounding as though, in much the same way, these additives for plants have the propensity to do more harm than good, in the long run! What about that?

I sure am glad that Weezie & Jiffymouse have said "there's no such thing as a stupid question around here" because I feel like I just fell off the last Turnip truck!

Hey Cyber-Sis, I may be Trouble Twin Two, but I would never do anything to you on purpose. I tell my students there will NEVER be anything on the exams that we have not covered in class, and the same holds true for you!

They are kinda the same thing, but I think Potash is water-soluble. I guess the different names are to confuse people like us!

Oh geesh, NOW you read the directions! :rolleyes: Thanks a lot Cyber-Sis, so that means I wouldn't have had to answer all these questions. Now I know why you are Trouble Twin One!

Correct amounts of all the elements are essential for good plant growth. The only difference would be the relative amounts required by the plants, and the areas where you live since certain areas of the country have nutrient deficiencies which others do not. Adding more than what is adequate could upset the nutrient balance of your soil.

Patty, I know two things about Epsom Salts and one is that it works wonders in a soak bath when you're sore and stiff from playing in the dirt. The other is that many, many years ago when I was young (told you it was many, many years ago) and I didn't know anything about gardening, plants, or anything that grew or was green except to add water, a friend told me to use Epsom Salts on my flowers and I did. Well, since they didn't die I just kept using it on my flowers.

Patty, I guess the issues you raised help explain why so many people are into organic gardening and organic foods.

I think it would depend on the type of additives you're talking about. Actually, fertilizers are only meant to make up for deficiencies in your soil which is why you should buy a fertilizer which contains only the nutrients you need.

I hope this answers some of your questions, but this ended up being longer than my dissertation. Next time you have a question, call me!

I think you answered all my questions. (And, you also beat me on word count by 116 words!)