Garden Guru’s Guide: How to Prune Smooth Hydrangeas for Abundant Blooms and Healthy Growth

Smooth hydrangeas (Hydrangea arborescens) are beloved for their large, showy flower heads that grace gardens from midsummer to early fall. While these plants are relatively low-maintenance, proper pruning is essential to maintain their health, vigor, and abundant blooms. This comprehensive guide will provide you with all the knowledge you need to master the art of pruning smooth hydrangeas.

Understanding Smooth Hydrangea Flowering

Before pruning, it’s crucial to understand how smooth hydrangeas bloom. Unlike some other hydrangea species, smooth hydrangeas produce flowers on both old and new wood. This means that pruning should be carefully timed to avoid removing potential flower buds.

Types of Pruning

There are two main types of pruning for smooth hydrangeas:

• Rejuvenation Pruning: This is a drastic pruning method used on overgrown or neglected plants. It involves cutting back the entire plant to within 6-12 inches of the ground.
• Maintenance Pruning: This is a more regular pruning technique that helps maintain the plant’s shape, size, and blooming potential.

When to Prune Smooth Hydrangeas

The optimal time to prune smooth hydrangeas is in late winter or early spring, before new growth begins. Avoid pruning in the fall or summer, as this can remove flower buds for the following season.

How to Prune Smooth Hydrangeas

Rejuvenation Pruning

1. Cut back all stems to within 6-12 inches of the ground.
2. Remove any dead, diseased, or damaged branches.
3. Spread a layer of mulch around the base of the plant to protect the roots and retain moisture.

Maintenance Pruning

1. Remove Old Wood: Cut back stems that bloomed the previous season to the ground.
2. Thin Out Crowded Branches: Remove any branches that are rubbing against each other or growing inward.
3. Cut Back Long Stems: Shorten any stems that are longer than 2-3 feet to encourage bushier growth.
4. Remove Dead or Diseased Branches: Always remove any branches that are dead, diseased, or damaged.

Pruning for Specific Shapes

Smooth hydrangeas can be pruned into various shapes, including:

• Round: Prune all stems to the same length to create a rounded shape.
• Vase: Prune the stems shorter at the base and longer at the top to create a vase-like shape.
• Tree Form: Remove all but one main stem and prune it to create a small tree.

Special Considerations for Bloom Color

Smooth hydrangeas produce white flowers that cannot be changed by pruning. However, some varieties, such as ‘Annabelle,’ may produce pink or lavender blooms if the soil is acidic. To encourage these colors, amend the soil with sulfur or aluminum sulfate.

Care After Pruning

After pruning, water the plant deeply and spread a layer of mulch around the base. Fertilize the plant in the spring with a balanced fertilizer to promote new growth and flowering.

In a nutshell: The Path to Hydrangea Perfection

Mastering the art of pruning smooth hydrangeas is essential for maintaining healthy, vibrant plants that will grace your garden with their stunning blooms season after season. By following the techniques outlined in this guide, you can ensure that your smooth hydrangeas reach their full potential, bringing beauty and joy to your outdoor space.

Quick Answers to Your FAQs

• Q: Can I prune smooth hydrangeas in the summer?
• A: No, summer pruning should be avoided as it can remove flower buds for the following season.

• Q: How often should I prune smooth hydrangeas?
• A: Maintenance pruning should be done annually in late winter or early spring. Rejuvenation pruning is only necessary for overgrown or neglected plants.

• Q: What is the difference between rejuvenation and maintenance pruning?
• A: Rejuvenation pruning is a drastic cutback to the ground, while maintenance pruning involves selectively removing old wood and thinning out crowded branches.