Organic fertilizer rec's

Hey guys I haven’t talked much about this on here yet but I am now growing veggies in mobile boxes at my work. We started this a year ago at Fair Park in Dallas in an asphalt parking lot. We donate all the produce to local organizations and the projects goal is to help fight hunger and provide educational opportunities as well as community involvement. I’m going to post more info about my project really soon. For now I want yo know what y’all use for organic fertilizer. We are keeping the farm organic and I think my biggest challenge will be keeping my soil healthy and fertile while my crops are growing. Any advice is welcome. This is quite the challenge. Can’t wait to hear from you geniuses as I know there are many of you are strictly organic. Thank you!


I’ve used cottonseed meal and soybean meal. I’m not sure how complete they are but a good start.

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@wildscaper, I like how you roll! I’m a huge fan of Dr Earth fertilizer products, the Tomato and Veg blend (for same) and the Acid Lovers for blueberries. For weekly/weakly feeding I use fish emulsion or Gro-Power liquid (a California company) I don’t know what a mobile box is, but I use EarthBoxes and they work great.

Good luck with your endeavors!

This is a pretty good reference.

This reminded me of something that was popular where I am originally from (@wildscaper grew up there as well so he may have known people who did this also). Fishing is very popular there and I remember many gardeners/fishermen filleting fish and burying the leftovers in the garden. With the emulsion, at least you don’t have to worry about the dog digging it back up and making a mess of the yard :grin:.

Oh yes I remember that well! Many an old timer told me of that trick heck if I had more time to fish I would use that too! Hope you can make it back home for some mudbugs.

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Thank you sir! I’m going to post more info about this project and some pics of the boxes soon so people can learn more about the project if so inclined. I’ll research those products. Many thanks!


Thanks for all the advice guys. More on this stuff soon!


I’ll be back there in a few weeks actually, but just a short trip. Not sure if there’ll be any crawfish boils at the time but hopefully so.

It depends on what you are fertilizing, what’s already in your soil and, with fruit trees, your purpose. Quick release forms (dried blood, human urine, fish emulsion) are great for mature fruit trees in spring, because that fast release feeds fruit and not vegetative growth. However, when establishing trees, you might want both fast and slow or be satisfied with slow release forms, although some fast in Spring when the soil is cool will accelerate establishment. Composted manures and alfalfa cubes are good sources of slow release N. Alfalfa has lot of K which fruit trees remove in large quantities once they are cropping, but many natural mulches are also very rich in K.

Synthetic nitrogen is pulled out of the atmosphere with natural gas, so it really is relatively natural no matter what anyone tells you, but the pressures of fashion are mighty in horticulture. Also the process contributes to global warming which some of us feel is an issue that transcends fashion.

Thank you for the very detailed response. Of course I will starting some fruit trees this year along with the veggies I am currently growing. That was great stuff. I’ll need to check my sources and see if I can get commercial sized supplies on those items. Thank you Alan.


One last thing. My beds are covered in a thick mulch layer and have to be to help the plants survive the tough Texas summer conditions. Are any of these products better to use as an over the top fertilizer? It seems that when I apply compost over the top of the mulch it dries up in the sun pretty quickly. Is it still doing some good? It is very hard to get fertilizer under the mulch layer while certain plants are actively growing if that makes sense. I plan on implementing liquid feeding fish emulsion or other organic liquid with a dosatron but I would think I would still need a solid slow release type fertilizer over the top. Thanks as always.


Quick release fertilizers placed against organic mulch tend to volatilize with significant amounts lost to the atmosphere (don’t ask me exactly what significant is, I’m simply quoting the literature here). If you can’t get fertilizer into or at least on top of the soil any other way, best to use something water soluble and water it in.

No, the compost does little good on top of the mulch, except to make the mulch thicker- might be better to use compost tea and save the compost to put down under the next layer of fresh mulch.

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That is sorta what I was thinking. I will add fresh compost every time we start a new crop for sure and use liquids. On some crops it will be easy enough to get fertilizer under the mulch so I will were I’m able. This is quite the venture for sure.

The OP was asking which organic fertilizers we are using on our vegetables.

You’re right and I missed that. Still, if you are concerned about the needs of the OP, you should be pleased he has found my answers helpful.


I like to use Alfalfa pellets as a mulch/ fertilizer on garden crops as well as fruit trees. I don’t know how affordable it is from the feed store in your area and some might argue that it isn’t necessarily organic with the prevalence of Roundup ready alfalfa seed ( probably not much cottonseed meal or soy that is absolutely clean either but if either were cheaper than alfalfa for me I’d use them).But for me it is affordable appears to be quite effective and I am not troubled by whatever residue may or may not be present. This coming from someone that does not use Roundup on anything. I also like to use dried kelp and kelp extract but that is kind of pricy so for your project may not be feasible. I’m also a fan of the newer class of fertilizers inoculated with micorrhizae. With those it shouldn’t take much to introduce favorable microbes in your beds. One other thought might be to introduce earthworms to your beds, they apparently do some foraging on living roots of crop plants but the gains should far outweigh any damage. Anyway it sounds like an admirable endeavor so good luck and keep up the good work!

The introduction of mychorizal inoculation of potting mixes is a research based development and can be useful in this relatively sterile medium, however, I’ve seen no research that shows an improvement in performance of normal, real soils that already are teeming with mychorizal fungi. We probably all know that marketeers will use any tactic that will increase sales, regardless of efficacy, so I’d like to see any research that supports this “innovation”. This came up on the forum a couple of years ago and I did a fairly thorough search to find that inoculation was only proven helpful in very unusual soils, such as in Alaska, where these fungi are not already established. If you have any information that shows new evidence I would be grateful if you would post it.

I believe that the multi-billion dollar commercial agricultural industry would be the first to respond to such research if it existed, and I’ve seen no evidence of these products used there- although I haven’t looked for it beyond reading trade magazines. I would also appreciate it if any forum members who are commercial growers and have seen such products offered in their fertilizer distribution networks would comment here.

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Brassicas do not utilize micorrhizae.

The introduction of mychorizal inoculation of potting mixes is a research based development and can be useful in this relatively sterile medium

When the OP started this thread it was about “mobile boxes” I should think potting mix is pretty much what is in them. Certainly these beds will be rich with microbes sooner rather than later given the description of heavy mulch, so why not try and manage it with the introduction of known beneficials?