How to Propagate mallow-flowered cranesbill?
Divide the tubers shortly after the foliage has been lost, but before autumn

mallow-flowered cranesbill · Geranium malviflorum
Best in full sun and with good drainage, but tolerates nutrient-poor soils and can be used in much the same way as spring bulbs, using annuals or neighbouring plants to occupy the space in summer
Divide the tubers shortly after the foliage has been lost, but before autumn