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help making a fertile soil

Posted by kawaiineko_gardener 5a ( on
Sun, Mar 18, 12 at 18:04

Long story short, I made my soil mixture last year. I used a variety of fertilizer (osmocote) that wasn't suitable for container gardening.

I didn't realize it wasn't until I called and asked how much of the fertilizer to use per container gardening, and they told me it wasn't suitable for container gardening. It didn't specify on the label that it wasn't, they just assumed people should know it wasn't suitable for container gardening, because the label didn't say it was.

By the time this happened, I had to dump my soil mixture, and make a new batch.

Didn't have time or money to add fertilizer that was suitable for container gardening. I tried to compensate by fertilizing on the surface of the soil mix, by using a liquid fertilizer.

This ended up over fertilizing the plants, stressing them out, and created a disaster....aphids were attracted cause of excess nitrogen in the soil and basically decimated my plants and harvest.

The soil mixture I have says you can add a 1/2 cup per 30 gallon batch of micro nutrient powder. I'm wondering if something called michorrihzae would be considered micro nutrients? Michorrihzae are soil microbes that make the soil more fertile.

If I were to add the michorrihzae could it just be mixed directly into the soil when I maix up the batch?

I was also told that if you don't have earth worms if your soil, it's a sign it's not fertile enough? Does this only apply to soil in the ground, or can it apply to soil less
mixtures as well?

In conclusion, what I thought would end up helping ended up
creating tons of problems. Since making my soil mixture is the most expensive part of container gardening for me, I really can't afford to screw up the soil mixture again, by fertilizing improperly. As such, I could REALLY use advice with this.

Follow-Up Postings:

RE: help making a fertile soil

I've used osmocote in container mixes for years without problems. in fact, I've often seen it recommended for this purpose. I don't know who "they" is, but I think they steered you wrong.

RE: help making a fertile soil

Mycorrhiza are a fungi that form a symbiotic (mutually beneficial) relationship with plant roots. In a good, healthy soil they will help move nutrients from the soil to the roots and benefit from some of the nutrients the roots have. In a not healthy soil they either will not exist or will not have any nutrients to move.
Almost any balanced "fertilzer" can be used in container soilless mixes. The problem is getting the right amount in the mix. Too much of any synthetic "fertilizer" could burn the plant roots, and the plant. Too little and the plants will not thrive.

RE: help making a fertile soil

W/Oscmocote, 2 varieties; one w/pink cap, one w/green. Pink=suitable for container gardening; green=for indoor and outdoor plants, NOT suitable for container gardening.

2010 used pink cap variety; just mixed it into my soil mix (make my own; 'recipe' says 2 c per 30 gallon batch).

2011 used green cap variety cause I thought N-P-K was more balanced. Didn't realize it wasn't suitable for container gardening cause it didn't specify this on the label.

I thought using more 'balanced' variety (green cap) would help plants. Since it wasn't designed for container gardening, it ended up creating huge problems.

I ask about the Mycorrhiza because my soil mix says you can add 1/2 c of microbe powder (this is optional).

Is Mycorrhiza considered a microbe powder? With my soil mix you mix in the Osmocote when you mix up your soil mix.

Could I just mix in the Mycorrhiza directly in the mix when I make it?

RE: help making a fertile soil

Kawaiineko, I just wanted to clarify that the pink cap Osmocote that's good for container gardening is labeled 'indoor and outdoor.' (You'd written the opposite.)

I'm interested in mycorrhiza fungi in containers and have purchased powders to try them out. MF are naturally occurring in the roots of plants, but not necessarily in containers.

From what I've read, you're right about the 1:1:1 ratio not being the best. I've also read in research studies that such a high ratio of phosphorus (the middle number) hurt MF development in containers after inoculation. They recommend low phosphorus fertilizers, like 3:1:2 ratio (pink cap).

About worms: Maybe the worm experts can weigh in here, but I don't think worms can survive in containers. I can't see either vermicomposting worms (red wigglers) or earthworms being happy in container plantings.

If you're interested in MF, check us out at the container gardening forum:

Here is a link that might be useful: MF testing

RE: help making a fertile soil

This is a very long post, my apologies.

Well I read the links in the thread you gave. I couldn't really make heads or tails of it. One thing I did notice is that certain ingredients in soil less mixes tend to inhibit the growth of the mycorrhizal fungi, specifically peat moss?

To counter act this, it recommends replacing part of the soil less mix with dirt and/or sand.

What sort of dirt? Dirt from the ground; if not that, then top soil? I have concerns mixing dirt into a soil less mix; afraid it will make the soil less mix too heavy or compact.

If I'm only replacing part of the soil less mix with dirt then would I have to worry about it being too heavy, compact and/or contaminating the soil?

Also where do you order the mycorrihiza? I find it on sites, but no way to order it online.

Also I'd just be mixing the mycorrihiza into my soil less mixture when I mix it up. Would this be a problem?

Is there any difference between mycorrihiza microbe powder and the mycorrhiza inoculant powder, or is it two ways of referring to the same thing?

Also which mycorrhiza powder should I use? I'd like one that will be good with vegetable and herb plants. Unfortunately I don't know too much about the varieties of mycorrhiza.

If I were to add dirt to my soil mix, should I reduce the amount of one the ingredients listed below? If so, which one?

Or, should I just add the equivalent amount of dirt as the spaghnum peat moss to the existing soil mixture? That is it says 5 gallons peat moss; if I were to add dirt (not reducing the amount of any of the ingredients in the existing soil mix, just adding to the existing mix) then how much?

The soil less mixture I generally use is listed below:

One batch makes 30 gallons. If I were to just measure out the microbe powder and mix it into the soil less mix I have below, how much per 30 gallon batch? Please specify this with a measurement (cups, gallons, etc.)

Also if the mycorrihiza doesn't produce a colony in the soil less mix, will it have any adverse affects on the plants/soil?

2-3 cu ft pine bark fines (pine bark mulch)
5 gallons peat
5 gallons perlite
2 cups dolomitic (garden) lime (or gypsum in some cases)
2 cups CRF (if preferred)

RE: help making a fertile soil

I responded to your other post but I see that you have a new question here.

Could you link me to the study that says that peat discourages MF growth? I have not read that. I actually just found a study that said MF growth occurred in a peat/verminculite mix in a greenhouse.

MF may not occur NATURALLY in a container, but they do grow after inoculation. This has been shown repeatedly in university studies. That's why we're doing our little experiments in the container forum, to see which brands are best at inoculating vegetables in containers. We don't have the answer yet to give you as to which brands are the best. You could join our little study by buying a different brand and adding to our comparison studies.

Also, I want to confirm you're growing them in containers, not raised beds, right?

RE: help making a fertile soil

Holy camolies this post is either way over my head or confusing. I think it's both. Why do they say composting is not difficult when it really is?

blah I think I'll just throw stuff out there and hope it heats up. Pretty much anything would be better than my crappy clayey soils.

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