Growing blueberries requires an acidic soil ph of 4-5.
In Florida, we have another concern. Because our water often travels through so much limestone before we get it out of the ground, it usually contains a high amount of calcium.
Calcium & iron can not be used by the plants at the same time. So excess calcium blocks some of the available iron for the plants. So many of our local growers suggest amending our soils with a little Ironite, in addition to the good suggestions in the video above.
Next, adding a soil acidifier amendment as a top dressing once a month is essential to successful blueberry production. It's not enough to just use some oak leaf or pine straw mulch. You really need that pH to be between 4-5 -- and every time you water, you're tilting the balance back to alkaline because of the high calcium content of our water.
Epsoma makes a formula called "soil acidifier" that we've found to be very effective -- and it is readily available usually at Home Depot, at independent feed stores, and through Amazon.
So, for success with blueberries: soil acidifier and ironite every month, in addition to the Magic Soil Formula --- especially for the trace minerals in the greensand.