Organic fertilizers for potted plants?

Hello everyone,

I’ve vastly expanded the container portion of my garden. I’ve read online that organic fertilizers don’t work exceptionally well in containers because the soil life isn’t as diverse and consistent as in the ground. Does anyone here grow in containers and exclusively use organic fertilizers with good success?

Thank you!

I do that with tomatoes. I grow in 15 gallon containers and use organic potting mix and Tomato-Tone. Works just fine for me.

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Do you use the same potting mix over and over but refresh it with the tomato tone?

I use urine with great success. Don’t use on blueberries or other acid loving plants

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I never had problems in containers with organic fertilizer. My soil breaks down quick enough in containers. Bacteria do not need to be introduced. They soon are plentiful in containers. Even wood chips break down. Yes a little slower, but not by much. If bacteria were low in containers the soil would be good forever. Unfortunately soil after a few years becomes rather fine grained and compact as the bacteria compost it.

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Thank you as always Drew!

Interesting but I think my family would be turned off to eating the fruits at that point.

I probably could, at least for two or three seasons, but I haven’t been doing so. I’ve been purchasing new potting soil and using the old stuff around the orchard.

For potted plants I just don’t see any additional benefit of using organic fertilizers. Abuse of fertilizers in general is the main problem, organic or not. The plant doesn’t care where it gets the minerals from.

But if it is a matter of principle, compost tea ought to do it. A slow release regular fertilizer would just be better.

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I too like to like to reuse the soil. In my case in raised beds. Usually between 3 to 5 years. I use a small amount of compost in my containers. I have found the 2nd year the soil is awesome. Growth is excellent. By the 4th year the soil is rather poor.

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I have absolutely nothing against non organic fertilizers, I use them in my garden. I just don’t like how often one needs to fertilize with them. I’m aware of osmocote but its pricey. Organic fertilizers are the perfect middle ground for me, I can find it at a reasonable price (albeit more expensive than non organics) and it slowly breaks down requiring less applications.

Sometimes organic fertilizers can be contaminated with PFOA / PFAS if they use the public wastewater system to source their nitrogen (poop). Be wary of “sludge” or “bio solids” as those most certainly will be contaminated. Those chemicals will then be absorbed into your crops and eventually to your body.

The “conventional” non organic fertilizer doesn’t have that problem. However, those white granular balls are generally salt based, so if you use them in containers you can apparently build up the salt content to a level that some plants won’t survive (strawberries can be sensitive to this). In ground use this isn’t a problem because the salt will eventually wash away.

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Buy it in bulk, by the 50-pound bag the stuff us dirt cheap. Even osmocote is about two a pound in bulk, a bit of an initial outlay but it doesn’t go bad. If you get the longest release one you apply it once a year.

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I am not so sure about the “not as diverse” statement.

But then anything I grow in containers has a base layer of homemade compost in the container. Plus real top soil either from my garden or field… and normally some black kow composted manure… and to that I add my own organic fertilizer mix… including bone meal blood meal gypsum greensand epsom salt.

If it is going to be in a container for more than a few weeks… I also include a deep layer of mulch on top… 2-3 inches of fine pine bark mulch works well. Moisture retention.

Every time I check to see if it really needs watering… the soil under that layer of mulch is moist and looks great.

I have some figs and apple grafts in 2.6 gal pots done like that… and they are growing exceptionally well.

I have a Novamac apple on b9 growing in a half whiskey barrel container… done like that and it looks very happy n healthy.

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