Scientists studied how different types of ericoid mycorrhizal fungi affect the growth of nine different plants related to heather and blueberries. They found that the benefits a plant gets from a fungal partner depend on which specific plant and fungus are paired together, and that a plant’s evolutionary family history can predict how well it will respond to different fungi. These findings could help conservation efforts restore damaged heathlands and wetlands by choosing the right fungal partners for each plant species.