Hi Robert - I'm a little late with my reply (new member) but maybe you will see this in time for the 2014 season.

Most commonly, vegetable plants that end up with lush, leafy plants with few or no blossoms or veggies or fruit are receiving too much nitrogen. Okra is not a particularly heavy feeder and Miracle Grow products are pretty high nitrogen. I think that you were probably on the right track with the bone meal but it may have been too late.

I have used commercial general purpose potting soils with added fertilizers in the past but have had more luck with container veggies by using my own mix of compost, a soil "lightening" agent such as vermiculite or peat, and a potting soil without added fertilizer. You can find recipes on the interwebs or if you prefer, there are commercially available container mixes. Gardener's Supply carries a nice one but it is kind of pricey. Then, you may want to fertilize with a half strength solution of fish or seaweed emulsion, or dig in a handful of kelp meal monthly. If organic is not a high priority, there are also higher phosphorous commercial fertilizers that are formulated for vegetables at larger garden centers. Look for a middle number higher than the first number.

If last year's crop did not have any disease or insect problems, you could try using the same soil from last year. Since the plants last year probably used a good portion of the nitrogen, you could fertilize lightly with a higher phosphorous product and see if you have better luck.

I really don't think it is the size of the container. Half of a 55 gallon barrel should be plenty deep and wide for a couple of okra plants each just as long as they are getting plenty of sunlight.