All things considered, Miracle Gro's blue powder fertilizer is not that bad but is not as complete as something like the Dyna Gro products, which tend to be highly favored by houseplant enthusiasts as well as container gardeners. Cn also be used in the garden although inground plants rarely have much of a need for regular fertilization,

As to why you need to use it, plants grown in containers, whether they be houseplants or hardy outdoor containers, are grown in potting soils that generally contain NO measurable plant nutrients or very short term ones. Since these are essential for healthy plant growth, they must be applied by the grower in the form of fertilizers.

Thanks, but looking at the Dyna Gro, they're not that different than Miracle Gro? In fact, the sources of the nutrients are the same, with the minor exception that the nitrogen source is mildly different but just as fast, the P and K are the same, and the balance of the minors are a little different. The major difference seems to be that it's a lot more expensive. If I wanted to slow it down, why not just use something like a little really watered down blood meal or something?

So I'm sorry, but the explanation doesn't make sense.

ETA: Here's the sourcing: Ammonium nitrate, calcium nitrate, potassium nitrate, mono-ammonium phosphate, mono-potassium phosphate, cobaltous sulfate, magnesium sulfate, boric acid, molybdic acid, potassium chloride, manganese, iron, copper and zinc disodium

Ammonium nitrate is fast N, Calcium nitrate is fast N. potassium nitrate is fast N, MAP is fast N... even urea is slower as the bacteria need time to process it and these are all salt nitrogen products.

In fact, this sounds like I'll be adjusting pH even faster than I might be with judicious Miracle Gro?

There are nutrients other than N, P and K that are required by plants - micronutrients or trace elements. The Dyna Gro products contain a better range of these necessary micros than does MG. And because it is diluted down so much compared to MG, any difference in expense is negligible.

As an organic, blood meal lacks most trace nutrients, is not fully water soluble and therefore requires the mineralization by soil organisms to be converted into a plant usable form. And populations of soil organisms necessary for this task that may be available in virtually any commercial potting soil are seriously lacking. Organics in containers are just very inefficient.

Regrettably, as I'm seeing that urea requires urease to process--bacterially generated--I still don't understand since it obviously works. I've also used very dilute blood meal in the past and again, it does work, really well and very quickly? Bacteria grow very fast, after all and it seems like once you establish them, you've got them?

I perhaps just don't understand? We have to sterilize everything because bacteria grow anywhere, particularly where you don't want them--wet and warm and dark particularly, with a reasonable pH of 4 to 10.

As there are three different Dyna Gro products with different ratios of majors and minors and micros that might apply, all very different (the hibiscus and pomegranate bloom irregularly, the fig doesn't, the cactus is a succulent that blossoms...) again, the ratios seem...less important as an argument here?

Urea is typically always synthesized for fertilizer purposes and as such is immediately available. Blood meal is entirely N and while containerized plants might recognize some benefit, it is not enough of a boost to be practical. Nor is it fully soluble and does require mineralization, again difficult to achieve successfully or efficiently in soil-less potting mixes.

If one understands how various fertilizers work, it becomes apparent why some just function better than others, especially when it comes to containerized plants. The precise ratios are less critical but it is recognized that plants tend to absorb NPK in a 3-1-2 ratio regardless of type. Both MG and Dyna Gro's Foliage Pro offer nutrients in this ratio.

All of this can be easily researched if you do not accept my contribution here. In fact, the Container Gardening forum discusses all this at great length.

I'm sorry, but urea synthesized for fertilizer is not chemically different (edited to correct that) and is not immediately available, it does have to be broken down first? And I've absolutely seen benefit from blood meal, although it does take a few days.

Apologies, but the rest of that simply implies that I don't understand how anything works after you've tried to tell me how urea works--incorrectly.

That's not very helpful, and I have been researching, hence the reason I know how urea works. It requires urease, an enzyme, to break down into ammonium nitrate so that plants may use it, and that requires bacterial action as bacteria produce urease. While hydrolyzation can happen otherwise, it is a very slow process and "it is not enough of a boost to be practical." I am pleased to have taught you something today, Gardengal48.

All of this can be easily researched if you do not accept my contribution here. In fact, a good chemistry class might be helpful.

So that was one interesting opinion, to say the least. Would anybody else care to chime in?

Thanks!

I agree with GardenGal. Get some DynaGro.

Thanks, Ken. And thanks for some logic here. I actually should have mentioned that I do regularly flush out the pots (the ones that go outside for summer regularly get flushed through, the indoor ones get flushed every few months). Medium changes also happen irregularly. Salt buildup is not likely.

Outside, those potted plants even get a good amount of organics. Contrary to claims, it works. Visibly. And beautifully. One of these days I should isolate a set of plants that get nothing but, although I'm sure the extremists wouldn't believe the data and would just respond poorly.

Rather than average performance, I tend to feature good, great, even stellar performance on everything, so consequently the "let's adjust by 0.0001%" on a trace element just didn't make much sense (and why I repeatedly asked for an explanation). It did sound like marketing to me, and why I wanted the reasoning...with proof.

This is also synching with further research and with people on other sites, so I'd say you're the most in the groove here...

I have stellar success with Miracle Gro, as well. I grow, from seed, thousands of bedding plants in cell packs every year, transplanting them to outdoor garden areas in the spring. I also have some permanent outdoor container plants of assorted kinds, and a few house-bound captives. All on Miracle Gro. I do inject humates and organics into my watering system for the garden plants and lawn a couple of times a year, with visible results.

Organics into the watering... I... I had not thought of that...

Oh, now there's an avenue of research for me. I can try that on my indoor plants and see if I can make it work, too, for something more gentle (yes, I'm very sure that a stratum will harbor bacteria, thank you!)