Summon thorn totems Grove mind in the top middle that makes the max totems summoned at once, when combined with unbound garden making 3 thorn totems summoned at once results in only 3 totems summoned at once. This is not the bug.
The bug is that Grove mind increases the mana cost by 15 per summoned totem, which the mana cost for healing totem in spriggan form takes the cost of if all the totems from both spriggan form AND thorn totem skill trees were to be created.