Many Geranium are tolerant of some or full shade indeed some such as Geranium nodosum, phaeum and sylvaticum are naturally woodland plants.
These are amongst the earliest of the geraniums to flower, in common with many woodlanders from Europe and North America these have a life cycle in tune to grow and flower before the leaves come on deciduous trees.
Trees naturally suck up huge amounts of moisture from the ground and dry the soil out during the Summer, particularly so in North America and Europe which have dryer Summers than Winters, unlike Asia which usually has wet Summers caused by the monsoon winds.
Geranium phaeum is very tolerant of dry soils and comes in a variety of leaf and flower colours. White, pale blue and rose pink tend to be the most popular. Growing to around 60cm in flower they have large palmate sometime strongly marked leaves.
Geranium macrorrhizum is tough and easy with the larger forms being evergreen, indeed showing good winter colours, of the tall forms Ingwersen’s Form (pale pink), Spessart (white with pink calx) and Bevans (strong Pink) are all good doers. The shorter Mt Olympus White (syn White Ness) is a true white, it’s cousin Pindus (pale pink) again originally from Greece can be deciduous.
Geranium sylvaticum is a British native and grows easily in a woodland garden or shady border with large blue, pink or white flowers in May and June.
Geranium nodosum is a strong grower with shiny foliage not unlike an Astrantia it will seed around but can grow pretty much anywhere you would like them to grow. In good soil they can be a pest but stopping them seeding will curb any excesses. A white flowered form is available but the usual colour is a pale lilac pink, strong purple flowered form are also grown.