Pruning hydrangeas can be a bit tricky because the timing and method depend on the type of hydrangea you have. Here’s a comprehensive guide to help you prune your hydrangeas at the right time and in the right way.

Understanding Your Hydrangea Type

1. Bigleaf Hydrangeas (Hydrangea macrophylla)

  • Includes: Mophead and Lacecap varieties
  • Bloom on: Old wood (last year’s growth)

2. Oakleaf Hydrangeas (Hydrangea quercifolia)

  • Bloom on: Old wood

3. Panicle Hydrangeas (Hydrangea paniculata)

  • Bloom on: New wood (current year’s growth)

4. Smooth Hydrangeas (Hydrangea arborescens)

  • Bloom on: New wood

5. Climbing Hydrangeas (Hydrangea petiolaris)

  • Bloom on: Old wood

Can You Prune Hydrangeas Close in Autumn?

For Bigleaf, Oakleaf, and Climbing Hydrangeas (bloom on old wood), it’s generally not recommended to prune them heavily in autumn. Pruning these types in autumn can remove the flower buds that have already formed for next year’s blooms.

For Panicle and Smooth Hydrangeas (bloom on new wood), autumn pruning is less critical, but it’s usually better to prune them in late winter or early spring to encourage strong growth and abundant flowers.

Best Time to Prune Hydrangeas

  • Bigleaf and Oakleaf Hydrangeas: Prune right after they finish blooming in late summer. This timing ensures you don’t cut off next year’s flower buds.
  • Panicle and Smooth Hydrangeas: Prune in late winter or early spring before new growth starts.
  • Climbing Hydrangeas: Prune after flowering in late summer if needed to control size and shape.

How to Prune Hydrangeas

1. Bigleaf and Oakleaf Hydrangeas

  • Deadheading: Remove spent flowers right after blooming.
  • Shaping and Thinning: After flowering, remove any dead, damaged, or weak stems. Cut back one-third of the oldest stems to the base to encourage new growth.

2. Panicle and Smooth Hydrangeas

  • Pruning Timing: In late winter or early spring, cut back the stems to about one-third of their height. For a more controlled shape, you can cut back more drastically if desired.
  • Shaping: Remove any dead or damaged wood. Thin out the plant by cutting some of the oldest stems to the base.

3. Climbing Hydrangeas

  • After Blooming: Prune after they finish blooming. Remove any dead or damaged wood and thin out to control size if necessary.
  • Shaping: Cut back any wayward or crossing stems to maintain the desired shape and encourage healthy growth.

Step-by-Step Pruning Guide

  1. Identify the Type: Determine which type of hydrangea you have to decide the best pruning time and method.
  2. Sterilize Your Tools: Use clean, sharp pruning shears to avoid spreading diseases.
  3. Remove Dead Wood: Start by cutting out any dead or damaged branches.
  4. Shape and Thin: Depending on the hydrangea type and the time of year, shape the plant and thin out older stems.
  5. Consider Light and Airflow: Ensure the plant has good airflow and light penetration to reduce disease risk.
  6. Clean Up: Remove all pruned material from around the plant to prevent pests and diseases.

Tips for Successful Pruning

  • Avoid Heavy Pruning in Autumn: For hydrangeas that bloom on old wood, heavy pruning in autumn can reduce blooms next year.
  • Regular Maintenance: Regular light pruning and deadheading throughout the growing season can keep your hydrangeas healthy and blooming well.
  • Mulching: After pruning, consider mulching around the base of the plant to protect the roots and retain moisture.

By following these guidelines, you can ensure your hydrangeas remain healthy and vibrant, providing beautiful blooms year after year.