For best results possible, yes you will need to provide some supplemental nutrients throughout the season.

Normally the only way that can be skipped is if the bed already has a well established soil food web to work on it and sufficient organic matter mixed in. That can take 3-5 years to develop depending on how hard you work at it. So keep first year expectations for your garden at a reasonable level, ok? :)

What you choose to use as your nutrient supplement is up to you but there are 100's of other products available besides the one you mentioned.

Also keep in mind that it is the plants you feed not the bed as a whole. In other words your supplements need to be focused on the particular plant's needs and they each have different needs.

You can either use one of the many liquid fertilizers as plant root drench or do side-dressing of the plants with a good dry, granular fertilizer. Learn your plants specific needs, the symptoms they will show when they need feeding, and the best times during their growth cycle to feed each.

And during this first season use every opportunity you have to add much more organic matter, usually in the form of compost or composted manures so your soil microherd can begin to develop.

Enjoy your garden.

Dave

My guess is your new soil mix is probably good for a few months, then you will want to watch your plants to determine what kind of boost they need, if any.

If you use a low analysis organic fertilizer you don't have to worry so much about overdoing things, you get a minor gain in organic matter and no pushing toward an acidic pH.

Your soil mix sounds excellent, but how long it provides nutrients will depend in part on rainfall. I like B Kow, but its analysis is less than 1-1-1, so at 30 percent volume I think you're low, and would topdress with an organic fertilizer or an inch of B Kow before putting down a summer mulch.

Definitely fertilize. Definitely use an organic. I nearly starved my plants the first year I had my raised beds. (I had incorporated a lot of wood chips and sawdust into the soil. That created problems until it broke down.) As Dave said, you want to feed the soil and get a good micro organism community going in there. I highly recommend the Espoma products (Plant Tone, Tomato Tone, Holly Tone, etc.). You will feed the soil and the plants. Many of us have become so accustomed to the big numbers on synthetic fertilizers, that we assume that organic fertilizers will be inadequate. It's not so. Most garden vegetables like regular feeding. The exception would be the bean family. They do much better with little or no added nitrogen. Start a compost pile. You will raise the very best fertilizer available right there for free.

I am a little more optimistic than these guys that 40% organic matter will get you through a season, but I have no objection to the advice above.

You might get by with mulching through the year, especially with something like used coffee grounds - I guess there is a middle ground where mulching becomes side dressing ... and sure, if things need a kick, liquid fertilizer can do that.

I personally like MiracleGro (and clones) more than I did in my youth. In the constellation of "chemicals" we face, it is one of the most benign.

I like to use an Espoma fertilizer as a slow release product to last the whole season. I also use some granular at planting. I use little on beans though.

Thanks to everyone for the great advice! Its very much appreciated!

I've been happy with Espoma products. And Neptune for a foliar feed.
I agree you should not need much right away and be a bit patient for your soil to 'mature' over the next few years as Dave pointed out.
Concentrate on the individual plantings needs from now on, rather than big broad strokes like miracle grow.
Side dressing, foliar feeding.

If you have pets, dogs, ...side dress a bit under the soil and under mulch to keep them out of it...some just love it and very toxic to their system. Even organic, even if it says safe around pets. Watch them and use your 'leave it' command. Small amounts ingested will not be harmful per say, but don't leave a bag opened on the ground or garage.

Thanks to everyone for the great advice! Its very much appreciated!