Blueberries are in the heath family, ericaceae. This means that they must have symbiotic fungi to live properly, being so adapted to having mycorrhizae as to not have root hairs. I did a bit of quick research, and it turns out the issue is weirder than I first thought. Plants of the family ericaceae, and specifically blueberries have a type of mycorrhizial association called ericoid mycorrhizae, typically fungi of the genus Hymenoscypus or Rhizoscyphus, and most typically Rhizoscyphus ericae. And without digging deep into weird places I doubt I could get culture of that fungus. If I were you, I would try and get a bit of soil/root mass from a thriving old established blueberry / wild vaccinium / cranberry / heath / rhododendron / heather plant in decending order of preference; and try and get said soil around the roots as a sort of seed to hopefully get the inoculation. No hurry, but the fungus is how they get their food to a large degree, unless they are in a nursery getting weak chemical fertilizers in the water, in which case they don't even need the fungus and it tends to atrophy unless fed.
Pee would be particularly good for blueberries, due to blueberries only being able to uptake urea/ammonium ions for nitrogen, as opposed to most plants preferring nitrate ion.
Shawn Harper wrote:This is good to know. I will make sure to inoculate all new plantings at new locations with soil from the old.
Bob Dobbs wrote:Meh, I managed to do it by just lumping forest humus around the roots after five years with no growth. I am specifically referring to rabbiteye blueberries I planted that receive no care or nutrients, and I have no scientific proof that the fungus caught other than the exponentially increased growth rate. I think a heavy downpour washed the soil down a bit, they were planted in a dished area that would allow that to happen instead of washing away. Never actually grew any rabbiteyes from seed, though I have grown a couple thousand from cutting.