[CH] Miracle Gro and other types of fertilizers; pots vs. soil
Brent Thompson (brent@hplbct.hpl.hp.com)
Mon, 14 Dec 1998 11:08:15 -0800
Nels Peterson <npkp4jp@polarcomm.com> wrote:
> The nutritional composition of miracle-gro isn't that outstanding
I wouldn't agree with this. I think the nutritional composition of
Miracle-Gro _is_ outstanding, in a sense. That is, Miracle-Gro is
formulated to meet the complete nutritional needs of plants, and it seems
to do the job quite well. I'm not trying to say Miracle-Gro is necessarily
_better_ than other brands of complete fertilizers (you can make your own
opinion), but it _is_ an attempt to be complete and it does work very well
for many people (of whom I'm one, though another brand has also worked as
well for me).
"Complete fertilizer" is in distinct contrast to the other main type of
fertilizer sold, the type that contains only the three major nutrients (N,
P, and K), the type we usually talk of with number triplets, like 10-10-10,
or 5-20-20, and such. Fertilizers of this type are very much cheaper than
complete fertilizers.
(Ok, for the sake of completeness we could say there's a third type, too,
namely individual nutrient components or specialized combinations of them,
e.g. iron sprays, zinc sprays, N-P-K with some iron or copper or calcium
added, etc.)
Complete fertilizers are required to get good plant growth in pots, where
the artificial soil medium itself is not capable of providing much of the
nutrients the plants groving therein need. Anything less than a complete
fertilizer will eventually result in potted plants experiencing a shortage
of at least one minor little nutrient, and that will slow the plant down,
and impair production.
Byron Bromley <Byron.Bromley@gsd-co.com> wrote:
> At the time of transplanting, add 3 tbsp Epsom Salts in a gal of water,
> feed each plant 1 pint. Add 1/3 to 1/2 cup 5-20-20, Then on a MONTHLY bases
> add 1 cup of 5-20-20. At the end of the season compare, plant stalk and
> the number of fruits. Also compare the amount of blosom drop I think that
> after 1st season you will throw that stuff out.
Most likely this is referring to plants growing in the soil. Soil contains
great numbers and amounts of components, and has great potential for
providing everything needed by plants. Usually, the 3 components most
rapidly used by plants are the ones most rapidly depleted from soils, oddly
enough. (Of course, every soil is different, due to base composition, and
cropping and erosional history). Hence, addition of N(itrogen),
P(hosphorus), or K(Potassium) more often than not is all that is required
to get good growth and production from plants growing in soil. Extra
Magnesium has been mentioned numerous times on chile-heads list as being
good for chiles.
So, the formula quoted above would be great for chile plants growing in the
soil. Only if your soil is deficient in some nutrient(s) present in
Miracle-Gro but not in commercial 5-20-20 fertilizer (i.e., besides N-P-K),
is the great expense of Miracle-Gro likely to be well spent for soil
application. (And if your soil did have such a deficiency, the cheapest
way to fix the problem would be to have the soil analyzed to learn what
specific minor nutrient(s) is needed, then just apply that single one/few).
[Of course, just as soils vary in the nutrients they can provide, so crops
also vary in the nutrients they require. Some fruit crops require more
Nitrogen than others, even though only fruit is still the goal, not
vegetative growth per se.]
> Throw that Mirical Grow as far as you can throw it. as least as far a
> veggies are concerned.
This is surely referring to the general rule that 'excess nitrogen is the
enemy of fruit production' (since it stimulates leaf and stem growth at the
expense of flowers). But, there do exist low-Nitrogen, complete nutrient,
formulations of Miracle-Gro (and its competitors) specifically for fruit
production, e.g. one called something like "Miracle-Gro for Tomatoes" --
this one is just as good for chiles as for their close relatives tomatoes.
Use this sort of product on chiles growing in pots.
[But of course there are other veggies, like spinach, lettuce, and the
myriad of other greens where flowers/fruit/seeds are not important, for
which regular Miracle-Gro or any other high Nitrogen regimen would be
superior.]
Manure / Compost
Manures and composted products typically provide mostly humus, not
nutrients (some minor nutrients are usually present, but these are nearly
always quite low in major nutrients). Humus is important for the
beneficial effect it has on soil structure. Most potting mixes are largely
organic in composition, so addition of more humus, like from manure or
compost, is pointless. So, again, major differences in fertilization
strategy between soil and pots:
Plants growing in soils generally benefit from addition of humus-adding
components, such as manure or compost, and major nutrients (N,P,K).
Addition of one or more minor nutrients may also be required, depending on
circumstances, though manure/compost often supplies sufficient of any minor
nutrients in low supply in the soil.
Plants growing in pots generally benefit most from -- in fact require --
fertilization with a complete fertilizer.
--- Brent