Hydrangeas grow best when they get full sun in the morning and shade in the afternoon, although some species, such as the bigleaf hydrangea, do well in only partial shade. Hydrangeas may be planted in the fall or spring.
When planting hydrangeas, dig a hole as deep as the root ball, but two to three times as wide. After placing the plant in the hole, fill it halfway with soil, water it and let it drain. Then, completely fill the hole with soil and thoroughly water it again. Hydrangeas require space, so they do best when placed three to 10 feet apart. If the leaves wilt, the plants need watering. Soil pH balances determine whether hydrangea flowers are blue or pink.