Many of us don't view the soil in a container as the source of plant nutrients, but fertilizers.

Many use strips of granular fertilizer in self watering containers with a cover. Others mix the fertilizer into the mix itself. My personal preference is to use a water soluble fertilizer in the water reservoir itself. In all cases though it isn't the mix itself providing the nutrients, but the fertilizer added so there really isn't a need to replenish the soil the way one would add compost to the ground gardens.

may I jump in here?

justaguy, are you saying that adding compost (e.g., composted cow manure) in with the potting mix is of no value? If that's what you mean, does adding composted material cause any harm in your opinion, if it does not create aeration problems?

I added Black Kow (composted manure) into my containers (not SWCs) this year with potting mix. I have had my share of issues (seems like everyone has this year though!). I used organic fertilizer when originally planting, although I read here it's really of no value in containers.

So now I'm confused....add compost? organic fertilizer? yes, no? Does it help, hurt or is it neutral?

(One thing I have begun to suspect is that the containers with the best drainage opportunity at the bottom (the more holes of significant size) fared better. Perhaps this allows more oxygen availability to the roots? Just a hunch I have based on my experience this year with containers.)

I can tell you that I added horse manure to some of my pots and they are doing much better than the ones without.

Ania

One reason to replace/replenish the soil in containers is because it tends to become compacted over the season. My practice has always been to put all end-of-season container soil into the nearly finished compost pile. Then the following spring I use about half and half finished compost and new potting soil for the containers. I also add a slow release fertilizer according to package directions or half strength if the commercial soil has fertilizer already in it. Then I periodically water with a soluable fertilizer during the growing season. This works well for me.

Sandy

So Justaguy2

What types and brands of organic fertilizers are good for replenishing the nutrients for the container's soil besides adding compost to it?

What types and brands of organic fertilizers are good for replenishing the nutrients for the container's soil besides adding compost to it?

I no longer use organic fertilizers in containers as I wasn't able to get consistently good results from them. I use water soluble synthetics in containers and organics in the ground gardens.

Many have reported good results with the Espoma line of organic ferts though.

The primary reason to avoid compost/manure in containers is that it breaks down and can cause aeration problems within a single season. A small amount in an otherwise fast draining mix isn't going to be the kiss of death, but studies done on compost in containers are pretty consistent in showing that the higher the percentage of compost, the lesser the growth rate of the plant.

There are those who strongly prefer this approach though and stick with it. To each their own.