Caring for Hydrangeas

Hydrangeas are one of the most popular plants in today’s landscape. They change everything in the landscape. A corner garden that was once in need of some color, add a hydrangea and you have instant success. Beautiful landscapes can be achieved with the simple use of a mass of Oakleaf hydrangeas underneath an allee of trees. A small group of three Original Endless Summer hydrangeas that shine bright blue all summer long provide easy success.

Here are some important tips to ensure your hydrangeas thrive:

1. Watering

• Watering Tools: When purchasing a hydrangea, it’s beneficial to buy a soaker hose with a timer. This will:
  • Decrease the time spent watering.
  • Ensure a deep and thorough soaking.
• Watering Frequency: Hydrangeas need a good, deep soaking a few times a week, especially in hotter weather.
  • During high temperatures, they will need more water.
  • If the leaves are wilting or drooping, it’s a sign they need more water.
  • Brown tips on the leaves indicate they haven’t been watered in time, but a deep soak can revive the plant.
• Water Stress: Water stress often becomes visible in the late afternoon, when the sun is hottest. This is when plants are most vulnerable to dehydration.

2. Starter Products

• Fertilizers: Not all fertilizers are created equal. Holganix Bloom is recommended for establishing hydrangeas:
  • Contains yucca extract, which reduces watering frequency.
  • It’s not a traditional fertilizer but rather a blend of beneficial bacteria and fungi that promote quicker rooting and establishment.
  • Holganix Bloom helps produce more vibrant blooms and can be applied three times throughout the growing season.

3. Changing Hydrangea Color

Hydrangea flower color can be altered by adjusting the soil’s pH:

• pH Scale: The pH scale ranges from 1 to 14, with 1 being highly acidic and 14 being alkaline.
  • The ideal soil pH for hydrangeas is around 6.0 to 6.5, which is slightly acidic to neutral.
  • In New England, the soil’s pH typically ranges between 5.0 and 5.5, which is perfect for evergreens.
• Color Changes:
  • Blue to Pink: Adding lime or lime-based products raises the pH and turns blue flowers pink.
  • Pink to Blue: Using sulfur or aluminum sulfate lowers the pH and turns pink flowers blue.
  • White Flowers: White hydrangeas may fade to pink or red but cannot revert to their original white once changed.
  • Red Flowers: Red flowers may shift to purple, especially with adjustments in pH.
• Important Note: Do not alter the pH in the first year of planting, as sulfur and lime can hinder the plant’s ability to establish itself.

4. Pruning Hydrangeas

• Pruning Time: The best time to prune hydrangeas depends on the variety:
  • Keep records of the hydrangeas you plant to know when and how to prune them.
  • Many newer varieties can be pruned on either old or new wood.
  • Check plant labels for specific pruning instructions (e.g., Proven Winners or Monrovia tags).
• Endless Summer Hydrangeas: These hydrangeas are best pruned in the fall, although they can also be pruned in early spring as they bloom on both old and new wood.
  • Wait until the plant is 3-4 years old before pruning to allow it to branch out.
  • In the first year, it may help to prune off 1-2 sets of buds to encourage better rooting.

5. Types of Hydrangeas

There are several types of hydrangeas, each suited to different garden applications:

• Mophead Hydrangeas:
  • Original Endless Summer
  • Enchantress
  • Let’s Dance Moonlight
  • Blushing Bride
• Lacecap Hydrangeas:
  • Twist n’ Shout Endless Summer
  • Wedding Gown
  • Tuff Stuff
  • Blue Billows
• Oakleaf Hydrangeas:
  • Snow Queen
  • Munchkin
  • Alice
• Late Panicle Hydrangeas:
  • Bobo
  • Limelight
  • Pinky Winky
  • Quickfire

For a comprehensive guide on hydrangea varieties, Michael Dirr’s book Hydrangeas for American Gardens is an excellent resource.