A 3:1:2 ratio such as 9-3-6 or 24-8-16. This is the ratio of NPK commonly available that best matches the ratio plants actually use nutrients.

While you didn't ask I will also tell you the ratio I would never purchase and that is any ratio where the middle number is highest. So called 'bloom formulas'. There are threads in this forum on fertilizing where you can get more info if you like so I won't elaborate further here.

As noted, for beginners and anyone who wants to be reasonably sure they can supply adequate nutrition w/o having to micro-manage, I would suggest Dyna-Gro's Foliage-Pro 9-3-6. It supplies nutrients in the ratio in which plants use them, and supplies all macros, secondary macros, and all the micro-nutrients necessary for normal growth. It also supplies a large portion of its N in nitrate form, which at times can be a significant advantage.

Al

That's odd. I have to look up the threads about the bloom formulas. I've had the most luck with high middle number. The years I've used it, my plants have been stunning. The years that I didn't use it the plants were just average.

I'll look into the Dyna-Gro. I just wish I didn't have to get specialty things like this online but I can't find them in any nurseries around here.

I should have mentioned that the majority of my plants are flowering.

I looked up the Dyna-Gro 9-3-6 and I'm confused. Isn't this just for foliage plants? Don't these ratios make the plant focus on vegetative growth and discourage flowering/fruiting?

They say that their 7-9-5 is best all purpose. What's the reasoning behind this?

A few years ago, I kept hearing that all the same numbers is the right way to go. Like, Dyna-Gro's 7-7-7. Wouldn't this make the most sense since the plant wouldn't be exposed to really high levels of anything?

Your plants seemed to have been doing well while using a high-P formulation, it was in spite of the extra P, not because of it.

Read more about high-P fertilizers here

and more about fertilizer strategies for containerized plants here.

Al

Additionally, much of what is offered/promoted by fertilizer companies is driven by demand, not necessarily what's best for plants. There is a lot of misinformation in this hobby and it's oftentimes easier and more profitable for a company to cater to it, rather than try to correct it. Al's links above will tell you everything you need to know when choosing a fertilizer.

Ms Minnamouse,

In regard to why dynagro and others market high P ferts the way they do, here is dynagro's CEO explaining it.

It's pretty much what Penfold2 said.

That's the thread I was thinking of when I was typing. Strange to hear a CEO speak so honestly about the limitations of their own product. At least they make a more appropriate formula for those who know better. Although I still have to order it because even the local hydroponics store, which carries Dyna-Gro products, only stocks the high P versions. Rrrr...

Find dynagrow on ebay for nearly half price. There is some good sellers on ebay still. Check ratings and feedback to be sure.

I used FP and protekt this year and am very happy with the results. however this was my first greenhouse year, so I'll really have nothing to compare except friends plants in the area I live.

What's FP?

FP is Foliage Pro, Dyna-Gro's 9-3-6 formula.

For those of you shopping for foliage pro 9-3-6 the free market is all over the place. I buy it for $29 a gallon but it is being sold for up to $59 a gallon. I cannot explain the difference in price for the exact same product. Al

I would and do use a balanced fertilizer. like 10-10-10 or 20-20-20 or even 15-30-15.

I am not a big fan of excessive nitrogen. It is great for lawns or foliage plants. but I think it can be detrimental to flowering and fruiting plants

What explains why the Dyno-gro blooming solution this year put tons on flowers on one of my citrus as an experiment, when in previous years the regular dyno-gro put more foiliage than anything?

A little confused about this too....I use FP whole heartedly. But looking at my meyer lemon FULL of blossoms using the blossom formula makes me question it also..

OP - 3:1:2 ratio fertilizers don't supply 'excessive' N. Plants use about 6 times more N than P, so 1:1:1 ratio fertilizers actually supply far more (excessive) P than plants can use in relation to N. The 15-30-15 you suggest actually supplies 12x as much P as plants can use in relation to N, unnecessarily raises the electrical conductivity and level of total dissolved solids of/in the soil, unnecessarily raises pH, and makes it more difficult for plants to absorb water and the nutrients dissolved in water - particularly Fe and Mn.

Al

So does supplying a product such as dyno-gro bloom work at first, then will eventually be detremental to plants over a short period of time?

If what your saying is true, then I should stop using it even though my lemon meyer has responded favorably this year to it, and feed that one Fp, and hope it gets as many blossoms...
Sorry if I am not op...But my question is related too..;-)

Mike - putting more of any one nutrient in the soil than plants can use or than they need is technically always detrimental to the plant. There is no way that 99.9% of hobby growers can scientifically justify using a fertilizer with the middle number (P) higher than either the first or last (N & K). It would take a skilled grower who is very familiar with fertilizers using the bloom-booster formula in combination with other specific fertilizers or chemicals to be able to build a case for their use. Actually, it would be very difficult to build a scientific case even for the use of 1:1:1 fertilizers like 10-10-10 and 20-20-20 w/o including a K supplement at a minimum.

I'm not saying that you can't grow healthy plants with 1:1:1 or high-P ratios, but I am saying it's more difficult and less forgiving than if you chose a 3:1:2 ratio fertilizer as your 'go-to' nutrition source.

Al

Got it.....Thanks for this...

Not willing to take a chance to continue use then..Want my plants to be healthy over the long term..

Since I have a long way to go before I even come close to being skilled at fertilizer use, other than what you suggested works well, I will stick with a pro's advice then..:-)

What explains why the Dyno-gro blooming solution this year put tons on flowers on one of my citrus as an experiment, when in previous years the regular dyno-gro put more foiliage than anything?

More than likely something other than your choice of ferts ;)

Even the CEO of DynaGro indicated the bloom formula was a marketing thing with little/no scientific basis behind it's existence.

Speaking purely of anecdotal experiments, I didn't use Protekt or any other K supplement on veggies this year that are regarded as sensitive to "excessive" N such as tomatos.

They still flowered and yielded normally with just a 3:1:2 ratio (Foliage Pro).

There are specialized fertilizers formulated for fruits such as Citrus. If you are not living in an area where citrus are a common tree they may not be available locally. However if you know it needs to be an acid type with three times as much nitrogen as phosphorus or potassium, such as 3-1-1 and contain trace elements Iron, Zinc and Manganese you should be able to find the appropriate fertilizer. When you want only ONE fertilizer for ANY plant that may be in a container there will have to be some compromises. Container citrus never stop growing and should be fertilized MONTHLY year around for best results. Al

Actually Al, what you just described exactly is MG 30-10-10 which the used to call 'Miracid', but what they now call their 'Azalea Rhododendron Cammelia' 'food', or something close to that.

Al

I must come here and admit that I failed to mention something about the dyno-gro for blossoms...

It might have contributed to more blossoms, but the leaves did suffer leaf color...All the citrus I fed FP to had much darker leaves, but not as many blossoms...They still produced though....
I'd say you would have call the FP a well balanced fertilizer, since the whole plant grows healthy, from the leaves, blossoms, and fruit, down to the roots...Thanks for so much insight in all this!

I hope mis_ minnamouse is finding her answer. For me it was FP for an all around feed..
All my plants, produced well...

As justaguy said, it could of been something else. I havn't gone a whole year yet using FP on that meyer, so it wouldn't be fair to say that FP wouldn't of done the same, with possibly greener leaves to boot, than what a high middle number fertilizer had to offer.
We'll see next time..

Oh yes,

I didn't have a use a special fertilizer to keep mine healthy....I didn't have to use MG 30-10-10, or any other special fertilizer on any of my acid loving plants...Just FP..:-0)