Growing Area

• Select a growing area in either partial shade or full sun. If summer afternoons are very warm in your area, plant hydrangeas in partial shade to protect them from afternoon sun. Improve the soil with large amounts of compost prior to planting hydrangeas to ensure rich soil and adequate drainage.
  
  

Planting

• In early autumn, dig a large hole that is twice as wide and twice as deep as the hydrangea root ball. Make sure there are no dirt clumps in the hole, and add approximately one inch of fresh compost to the bottom of the hole. Take the hydrangea plant out of its pot and break up the soil around the outside edges of the roots with your hands.
  
  Place the hydrangea into the hole, making sure it is at the identical level it was while it was in the container. If necessary, add more dirt to the bottom of the hole to bring the hydrangea up to the proper planting level. Add soil back into the hole carefully.
  
  

Water, Mulch and Fertilization

• Water the hydrangea well immediately after planting. Try to keep hydrangeas evenly moist throughout the growing season. Keep hydrangea shrubs well watered during especially hot weather.
  
  Mulch generously around the base of the hydrangea shrub. Add fresh mulch every spring to keep the soil rich and moist.
  
  Fertilize hydrangeas once a year in the spring with an all-purpose fertilizer. Use approximately 1/4 cup of granular fertilizer for a small shrub and up to 2 cups of fertilizer for a large shrub. Do not allow the fertilizer to touch the trunk of the shrub.
  
  

Pruning

• Cut back old growth in the spring before the growing season begins. Remove old flowers, but take care to avoid cutting any new growth. Remove flower stems as they finish blooming throughout the summer.
  
  After the hydrangea has finished blooming for the summer, prune back the stems only to the point just above the first group of leaves on the stem to avoid disrupting next year's blooms.
  
  

Bloom Colors

• Some varieties of hydrangeas will change bloom colors if the soil conditions change, because the pH level of the soil determines the color of the blooms. Highly acidic soils produce blue blooms, neutral soils produce white blooms and high-alkaline soils produce pink blooms.
  
  Add lime to your garden soil to produce pink blooms and add aluminum sulfate to your soil to produce blue blooms. It will be necessary to amend the soil in this fashion at least twice over the summer months, and it may take up to two years to see bloom colors change.