The only way to know how much plant food to add to any gardens soil is by having a good soil test done.

What is the pH of that soil?

What is the level of Phosphorus and potash in that soil?

What is the level of organic matter in that soil?

I don't think it matters. You can add it or not. I'd probably add it because it breaks down slowly anyway. 1/3 of a cup of organic fertilizer isn't really that much.

"I thought potted plants couldn't use organic fertilizer"

They can't........or at least dry organics.......with any degree of efficiency. That doesn't stop the manufacturers from pushing them for that use.

And for a raised bed vegetable garden, I wouldn't worry about soil testing. Most are flled with imported soil (rather than your garden soil) and act more like a container planting than inground gardening in that the imported soil is of dubious fertility and the gardener is really the one to provided any nutrients. And even in a inground situation, veggies typically need supplemental fertilization during the growing season since they consume so much.

Follow the applications as per the label, including the monthly side dressing. Because the GardenTone is a slow release product as well as having a pretty light nutrient load compared to a synthetic fert, you will not be overapplying.

@Boris Zakharin: It is not an instant solution answer, but if you are serious about gardening and plan to have a garden that will give you pleasure, health and satisfaction in the long run then forget the fad of raised beds and start building your soil naturally at the ground level.

There is little to justify building raised beds. In most cases it is an unnecessary and wasteful use of effort and other resources, leading to worse and worse results and, eventually, to the abandonment of the idea altogether.

What was your reason for building raised beds? Is your soil waterlogged, or contaminated?

Well, let's get in to the reason for raised beds.

It begins with the fact that so much of the land we want to use for gardening has been compacted down by years of walking over it. One human step crushes much of the air out of about 10" of soil. Plant roots depend on aeration. Soil in it's natural state has years of decomposing material lightly resting on the surface with whole communities of organisms feeding and sheltering below.

You raise the soil by turning in amendments like compost and/or manure. (And as long as you keep your feet out of the bed, you never have to do that digging again.) If you work down about a foot the amendments plus the air will raise the soil level about 4 inches. On top of that you will want to put mulch (like straw or shredded leaves) during the hot summer to regulate soil temperature and moisture. You will do the same when you "put things to bed" for the winter - a thick layer of mulch to prevent weeds and provide cover and insulation for worms and bugs that overwinter.

You (optionally) build walls around the raised bed to contain this material and make the most of your space. But the biggest reason to build a barrier is a reminder - DO NOT WALK HERE. Once that soil has air in it, you never want to set foot in there again. If you can, build something high enough to contain the aerated soil + about 4 or 5 inches of winter mulch. That would mean something along the line of 8 - 12" high. It doesn't have to be that high - but the mulch will go over the top. It really shouldn't be much higher or you are putting too much distance between the top of the bed and the topsoil below. You want those minerals and organisms to be prominent in your raised bed.

Yes, eventually the aerated soil will settle - but the constantly decomposing mulch will take up the difference giving you a light top layer of compost.

Of course there are other reasons people have - they look good, or they make it easier to reach. But the main reason is to add air and amendments into a confined space.

You don't need raised beds to do that - particularly if you have a lot of land. You could just divide a large garden into beds by establishing paths - again separating the garden in walking and non-walking areas. That works as well. But raised beds are a better solution where space is limited and you have to get the most out of confined area.

My raised beds are made from 2x8 lumber so realistically the soil level in my beds is probably closer to 6.5 inches above the surrounding soil. It tends to be somewhat swamp-like in my barkyard in early spring so raised beds, even relatively short ones are needed and prove invaluable.

My reason for using a 2x8 frame around the beds is to help keep the soil from migrating out of the bed and to keep grass and weeds, primarily creeping charlie, from getting in. The tidy look of the beds is a plus. I have gardened in raised beds without a physical border by just mounding up the soil and it does work but I do not prefer it.

If I had the space and my ground wasn't so waterlogged I would be planting in the ground. But I also know that in 20 or so years when my back and knees eventually start to cause me problems I'll be looking to tall raised beds for ease of gardening.

To call raised bed gardening a fad and to say that you'll get "worse and worse results" from gardening in raised beds is absolutely ridiculous.

I would use the Garden Tone as needed, using the plants themselves as a guide or indicator. If your plants are growing fine then you may not need to fertilize. If they start to stall out, turn yellow-y, or just start to look unhealthy then they could probably use a boost. Just remember that most organic fertilizers are slow acting so your plants may not respond immediately.

Rodney

Agree with the above! Additionally, in community gardens, like the one I belong too, space is at a premium, and a raised bed is the only option many of us have. After 4 years, the soil in my raised beds is incredibly productive, because i have been careful to provide amendments and - as was mentioned above - avoid compacting the soil by walking on it. Weeding is a breeze, as well!

Thanks for your posts Richard Brennan and theforgottenone.

@ Richard Brennan: What you describe in your post is a long and continuous process of building up (you call it raising) the soil. What you are doing is exactly what I would recommend to anybody who is serious about gardening and growing healthy and nutritious food. If you had read my post more closely you would notice the sentence there: "forget the fad of raised beds and start building your soil naturally at the ground level".

The approach you describe, and I wholeheartedly endorse, is exactly opposite to building raised beds as commonly understood and described by the OP: "So last year I got a new 4'x6' raised bed made and filled by a third party." or by gardengal: "Most are flled with imported soil (rather than your garden soil) and act more like a container planting".

The process of building up the soil leads, as you rightly observed, to the raising of the cultivated soil above the level of the surrounding uncultivated ground. And here exactly lies where the fad of raised beds (as commonly understood and described by the posters here) originated from. Namely, some people who simply noticed the final results but didn't know or understand anything about the process of building up the soil, came to the conclusion that things grow better because the beds are "raised", and not because of any other reason, started promoting "raised beds" as a method of gardening. Sad.

@theforgottenone: "It tends to be somewhat swamp-like in my barkyard in early spring so raised beds, even relatively short ones are needed and prove invaluable."

It looks like you, too, haven't read my post carefully enough before rushing to respond. In my post directed to the OP I clearly made an exception for where the conventional "raised beds" approach could be justified. I wrote: "What was your reason for building raised beds? Is your soil waterlogged, or contaminated?". I suppose "swamp-like" is equivalent, or at least very close, to waterlogged.

As always, there is something good in almost everything, so your not paying enough attention to the contents of my post has lead to clarification of some things, what is good :-)

As for the conventional raised beds looking good, well, it is a matter of taste. It also makes me wonder how many trees are sacrificed to satisfy that, rather questionable to say the least, fad.

WTF?? Why in the world would any raised bed need to be justified? It is a gardening choice that can be undertaken for any number of reasons that do not require explanation or justification. You do not need to justify your need to plop down a tree in the middle of the lawn.......a raised bed gardener does not need to justify their reason for using a raised bed.

There is nothing inherently better with "builiding up" inground soil to an elevated level than there is to building a box and filling it with imported soil - this "fad" you seem to abhor. Both are equally able to result in productive and healthy plant growth and both will need attention, added amendments and fertilization over the years to remain productive.

btw, a whole host of materials other than lumber can be used to create a raised bed.....includng NO material at all.......so no need to worry overly about "sacrificing trees"!! LOL!! And yes, it is just a matter of taste....just as plopping that tree down in the middle of the lawn is a matter of taste.

I'm not sure if it is the weird weather many have experienced these past few months or some other unknown explanation but after 25 years on the GardenWeb forums I can't recall ever encountering so many adamant but unsubstantiated viewpoints about topics that are neither here nor there in the vast scheme of things. It's a puzzlement........

I totally agree gardengal48. We are in an urban setting and raised beds are perfect for us and extremely productive. Your last paragraph is spot on as well.