Hydrangeas are a beloved addition to many gardens, prized for their stunning blooms and vibrant colors. However, caring for hydrangeas can be a bit tricky, especially when it comes to understanding the unique needs of each type for lighting, watering, and pruning. Let’s explore the differences between four main types of hydrangeas – Hydrangea arborescens, Hydrangea quercifolia, Hydrangea paniculata, and Hydrangea macrophylla – to ensure your hydrangeas thrive in your garden.
Lighting Conditions: Each type of hydrangea has specific lighting requirements that can affect its growth and blooming. Understanding these nuances allows you to choose the right hydrangea for your garden’s conditions.
Hydrangea paniculata
Panicle hydrangeas are the most sun-tolerant of all hydrangeas.
USDA Zone 3-6: At least 4 hours of direct sun daily. Preferably 6 or more hours for robust stem development and abundant flowers.
USDA Zone 7-8: Afternoon shade is beneficial. Still require some sun daily for optimal growth.
Hydrangea arborescens
Smooth hydrangeas thrive in partly shaded locations. They benefit from the morning sun, which supports blooming, but they require shielding from the hot afternoon sun.
Hydrangea quercifolia
In their native habitat, oakleaf hydrangeas are commonly found along stream banks, hillsides, and in open woods. Due to their natural environment, they appreciate the dappled shade provided by large trees. Oakleaf hydrangeas look particularly stunning when planted in woodland gardens, where they can showcase their beauty amidst the natural surroundings.
Hydrangea macrophylla
Bigleaf hydrangeas thrive in sheltered spots with partial shade. Generally, the hotter the climate, the more shade your plant will need. However, for optimal blooming and vibrant coloration, some sunlight daily is important, as they will not bloom in full shade.
Watering: All hydrangeas appreciate moist, well-drained soils, but Panicle Hydrangeas and Oakleaf Hydrangeas can exhibit some drought tolerance, making them suitable for planting under big trees or in areas with limited rainfall. However, you can address this issue with a drip irrigation system, allowing you to easily grow Smooth Hydrangeas and Bigleaf Hydrangeas, which have higher water requirements. Don’t forget about mulching! Mulching is highly beneficial for hydrangeas as it helps conserve moisture and regulate soil temperature. To mulch your hydrangeas effectively, apply a layer of organic mulch, such as bark chips or compost, around the base of the plant.
Pruning: Pruning is often considered one of the most challenging tasks for gardeners when it comes to caring for hydrangeas. Let’s delve deeper into this topic to shed light on the intricacies of pruning hydrangeas.
Old Wood Versus New Wood: Understanding whether a hydrangea blooms on old wood or new wood is crucial for determining the appropriate time for pruning. Some hydrangea species bloom on last year’s growth, referred to as “old wood.” This old wood contains the flower buds that will open in the coming summer. It’s essential not to cut off these flower buds during pruning to avoid missing out on the beautiful blooms. A light trim in early spring is typically all that’s needed: Simply cut back any old flower heads to the closest leaf nodes.
Examples of hydrangeas that bloom exclusively on old wood include:
- All oakleaf hydrangeas
- Bigleaf hydrangeas that are not rebloomers
In contrast, hydrangeas that bloom on new wood produce flower buds on the young growth that emerges in spring. Since the buds are not present during the winter months, these plants can be pruned in late winter or early spring before new growth begins.
Examples of hydrangeas that bloom exclusively on new wood include:
- All smooth hydrangeas
- All panicle hydrangeas
Pruning Reblooming Hydrangeas: Reblooming hydrangeas pose a unique challenge as they produce flowers on both old and new wood. This makes it difficult to find an optimal time to prune them without sacrificing some flowers. Reblooming cultivars should be pruned similarly to hydrangeas that bloom on old wood, meaning you should only need to prune out a few (if any) dead branches in the spring once the plant starts to leaf out.
Examples of reblooming varieties include:
- Reblooming varieties of bigleaf hydrangeas
Let’s simplify things and create a straightforward summary. You can save these pictures and prune your hydrangeas confidently to ensure abundant blooms.
Panicle hydrangeas and Smooth Hydrangeas bloom on new wood, allowing them to be pruned in spring without negatively impacting their bloom. The simplest pruning method involves cutting the plant back by about one-third of its total height, while also removing any thin, spindly stems. This medium prune results in a controlled yet natural appearance, with medium-sized flowers and fresh growth each season.
However, pruning can also be utilized to manage the size and abundance of flowers, as well as the overall size of the plant.
Hard Pruning: For a more drastic approach, you can opt to cut your hydrangeas to around 20cm above ground level. Although this may lead to fewer blooms compared to light or medium pruning, the blooms that do appear will be remarkable showpieces, and this method can help maintain a more compact plant.
Light Pruning: Alternatively, you can trim the plant just below each flower head, essentially ‘dead-heading’ it. This tidies up the hydrangea and encourages the stems to grow slightly taller over time. While this method yields smaller flowers compared to deeper pruning, it results in an abundance of blooms that can support themselves more effectively.
Oakleaf Hydrangeas and Bigleaf Hydrangeas bloom on old wood, which means they require light pruning in spring. This involves trimming the plant just below each flower head, essentially ‘dead-heading’ it.
Companion Planting: If you’re looking to elevate your hydrangea displays, companion planting provides a chance to craft breathtaking combinations. I’ve carefully selected the best plant pairings and compiled them into a workbook titled “Companion Plants for Hydrangeas: 42 Planting Schemes with Hydrangeas for Every Style.” You can download the workbook here
You also can check my previous posts, where I share few planting schemes from the workbook:
Enhancing Your Garden with Smooth Hydrangeas: Care Tips and Planting Ideas for Hydrangea arborescens
What to Plant with Oakleaf Hydrangea? 3 Ready-to-Use Plant Combinations for Hydrangea quercifolia
In these posts, you’ll discover carefully curated combinations that harmonize with specific hydrangea varieties, enhancing their aesthetic appeal and creating captivating garden landscapes.
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