There are several discussions on the container forum about the difficulty of organic fert in containers. You may want to cruise over there and see if anything sounds familiar. My first suspicion was the soil lacked adequate nutrition, then I saw what you were fertilizing with.

Dan

Here is my 2 cents...I think that the principles of SF gardening are wonderful, but the actual practice is very flawed. You have beautifully constructed raised beds, but look at how much space you lose in them by using the dividers. The zucchini will certainly swamp the whole box and should be properly grown in its' own container and given lots of room to sprawl (on the deck) The strawberries will bear such a small quantity of fruit, therefore (to me) that space could be used for something that doesn't mind crowding (like lettuce) I would think growing vertically in this box...tomatoes, cukes, pole beans come immediately to mind.

I agree with lonmower that the zucchini will soon start overrunning your beds. You might have to make a choice to abandon somethings, move somethings to other areas if possible or just let it be and hope for the best.

Is your mix soil-less?

My experience with soil-less planting mix is that it works great for small pots which will be changed out after a few seasons. For raised beds however, I've experienced exactly the problem you have. Seedlings will do great, then after a long while come to a halt. There's not really many alternatives other than what you're doing: fertilize like crazy. If slow fertilzer is not enough, you probably need to use liquid fert. Nowadays I only use soil-less mix to start seeds so I don't know of many organic liquid fertilizer. Maybe someone else can help out with the liquid fertilizer. Try that and you should see improvement soon.

The mix should be good. But maybe next time when you amend, you can add some quality soil that will hold nutrients a little better than the soil-less mix.

Well, now that the subject's been breached, yes, zuke is one of those that, in this situation, can be bought at the store. The production/ft3 is low by the end of the summer. There are only so many zuke you can eat, and that 'so many' comes early in the season, far before production ends. Far better plants to grow in this place.

But as far as the potting soil goes, this setup should be considered a pot. Treat it like a pot. You must refresh the soil in your pots inside. Same here. The container forum has a great resource, 'Tapla', and search on his screen name and follow his tutorials. He'll write a book one day, and it will sell very well.

Dan

I have had issues with the square foot garden soil mixture suggested in the books. In hot climates, the soil just doesn't hold water and nutrients (because you are watering so often). I suggest reducing the vermiculite and adding more compost.
I would add more compost with each garden planting, and yes, be sure to fertilize with anything appropriate. I garden organically in raised beds with HUGE production (I also garden organically in containers without issues) - I use Steve Solomon's fertilizer mix (Gardening When It Counts) and liquid fish fertilizer (because I use alfalfa for the seed meal and it burns out fairly quickly) - I've added dry molassas to the fertilizer mix lately with amazing results. I mulch everything really well and try to water as little as possible, only what is needed.

Good luck, I hope you can keep things growing and producing for you.

As far as fertilizer goes, I've had great results mixing worm castings, bone meal, and greensand (about 5:2:1) in with the potting soil at the start of the season, and top-dressing again 2 to 3 months later.

As for overcrowding, you may want to get a very large pot for your zucchini, sink it into the soil, and lift it every week or so to prevent its roots from getting out of the pot. Or build a real partition for it, or put it by itself in one of the 1x3s.

Your soil mix sounds a little dubious. Peat moss has two undesirable properties: it's very acidic (most peat-based potting soils contain some lime to balance the acidity); and it's hard to keep properly wet. I've had containers of peat-based soil that would just shed water. After a thorough watering, I could look underneath the surface and see that almost all of the "soil" was still dry. This generally stunts the growth of whatever's growing in it. Pots can be sunk in a basin of lukewarm water once in a while so that they're forced to saturate, but you can't do that with your gardens. Your zucchini may have sunk its roots down into a lower layer that stays wetter for some reason, maybe because of slow drainage (which is another hazard for containers placed directly on a flat floor).

My favorite potting soil is Ocean Forest. Your garden center or hydroponics store may stock it or be able to order some, so that you don't have to pay shipping. It comes with a good amount of organic fertilizer, and you can add the mix I mentioned above when the nutrients start to deplete, and at the start of next season. It also seems to do a good job of holding moisture. I'll bet it makes a big difference.

More compost and rock dust or Greensand at about a pound per square foot is fine.