Incorporate compost, well-rotted manure or mushroom manure thoroughly into the top eight to 12 inches of soil with a spade. Organic matter holds nutrients and water in the soil and helps prevent stress from fluctuations in soil moisture levels. They will grow better with feeding and mulching and regular watering in dry weather.
Plant hydrangea plants at least 4 foot apart and mulch with compost or well rotted manure yearly. This suppresses weeds, reduces soil drying and feeds the plant.
Hydrangeas make fine container plants, flowering for many months.
They must be well watered. Hydrangeas like water (hydor is a Greek word for water). They all benefit from the occasional liquid/foliar feed with a high potash fertiliser such as Phostrogen, Tomorite or Miracid (not Miracle Grow) to fertilize the plants. Follow the printed instructions - use approximately every two weeks in the growing season for maximum size, and to encourage the formation of flower buds.
The leaves will begin to droop if the soil is too dry. Too much water and the leaves begin to get black marks on the edges.