Golden-saxifrage is a tiny, mat-forming plant of wetlands and seeps. The inconspicuous flowers are noticeable only for their eight brick-red anthers when it blooms in May.
During a hot spell in the summer, some of the plant's leaves are likely to become scorched if the plant is grown in full sun. It may recover when cooler temperatures return, but it is simply easier to grow the plant in shade.
Add compost to the soil for nutrients. Applying garden mulch will not only conserve moisture in the soil but also help the plant to overwinter (mulch is especially helpful in zone 5).
They like wet (but well-drained) soil, making it easiest to treat them as shade plants (where moisture will evaporate less quickly).