Boron needs to be present in any successful Super Soil, but do not overdo it.

When boron in soil is too high or too low, plants will not grow correctly. Boron is a micronutrient necessary for plant growth. The balance of too little or too much between plants and boron is a delicate. Heavy boron soil concentration can be harmful and sometimes toxic to plants. Without boron in the soil, plants may appear healthy but will not flower or fruit. 
 Boron helps keep control the of sugars in plants. If you think your super soil might have a boron deficiency problem, use a small amount of boric acid (1/2 tsp. per gallon of water) as a foliar spray. Be careful as you use boron on plants. Again, too much boron can be toxic.

  All plants must have boron for normal, healthy growth. Boron is as critical as nitrogen and other elements that plants need in larger amounts. Boron affects plant growth, but it especially impacts fruit set and ultimate yields on vegetable crops. It controls how vegetables process carbohydrates and move the sugars that control fruit taste, quality and color.

 The actual boron needed to correct common Super soil deficiencies is as low as 1/2 to 1 ounce per 1,000 square feet. Apply the recommended boron to the soil, and water the area to move boron into the root zone.