Understanding Hydrangeas

It’s Hydrangea Season! Explore the diverse world of hydrangeas and discover the top types recommended by professionals to enhance your outdoor spaces.

Hydrangeas are a diverse group of flowering shrubs (and even vines) known for their stunning and showy blooms. There can be confusion with the hundreds of different varieties on the market but they fall into several different categories which can help understand their use and limitations in the landscape. With proper planning and care, hydrangeas can be a beautiful and rewarding addition to any landscape.

We use mostly Panicle Hydrangeas, occasionally some Smooth Hydrangeas, and you will find out why with the Pros and Cons listed for each type.

Panicle Hydrangea (Hydrangea paniculata)

These hydrangeas have elongated, cone-shaped flower clusters. One of the unique characteristics of panicle hydrangeas is their ability to change flower color as they mature. The flowers typically start as creamy white or light green and may turn to pink, burgundy, or even shades of red as they age, creating a stunning multi-colored display in your landscape. Panicle hydrangeas are excellent landscape plants due to their hardiness, low maintenance requirements, long-lasting blooms, color-changing abilities, and their ability to attract pollinators, adding beauty and interest to your outdoor space throughout the year.

PROS:

1. Hardiness: They can thrive in a wide range of climates, making them suitable for various regions, including colder climates where other hydrangea varieties may struggle.
2. Low Maintenance: Compared to some other hydrangea species, panicle hydrangeas are relatively low maintenance. Once established, they require minimal care.
3. Long-Lasting Blooms: The large flower clusters can last for several weeks or more. As the flowers age, they often change color, offering visual interest throughout the blooming season.
4. Size and Shape: Panicle hydrangeas come in various sizes and shapes, from compact shrubs to large, almost tree-like forms.
5. Sun Tolerance: Panicle hydrangeas can tolerate more sun exposure than some other hydrangea species, although they still appreciate some shade during the hottest parts of the day.
6. Drought Tolerance: Once established, panicle hydrangeas have good drought tolerance. While it's essential to provide adequate water during dry spells, they are generally less susceptible to water stress compared to other hydrangea types.
7. Attracts Pollinators: The large, showy flower clusters of panicle hydrangeas attract pollinators like butterflies, bees, and other beneficial insects, contributing to a vibrant and dynamic ecosystem in your garden.
8. Seasonal Interest: Apart from their beautiful summer blooms, panicle hydrangeas can add interest to your landscape in other seasons as well. In the fall, the foliage may change to lovely shades of red, orange, or yellow, and during winter, the dried flower heads can add texture and visual appeal to the garden.
9. Versatility: Panicle hydrangeas can be used in various landscape settings, such as borders, foundation plantings, hedges, and even as standalone focal points. Their versatility and ability to blend well with other plants make them a valuable addition to any garden or landscape design.

CONS

1. Pruning may be required: Panicle Hydrangeas bloom on new wood, so annual pruning will encourage new growth and flowering, and prevent them from becoming leggy. Some varieties of Panicle Hydrangea can grow quite large, which may not be suitable for smaller gardens or tight spaces.

Smooth Hydrangea (Hydrangea arborescens)

These hydrangeas feature round, dome-shaped flower clusters. One of the most well-known varieties in this category is 'Annabelle,' known for its abundant and large white flower heads.

PROS

1. Hardiness: Can survive harsh winters and severe cold. Native to the Eastern US.
2. Long-Lasting Blooms: Large flower clusters can last summer and into fall. The dried flower heads can provide fall and winter interest.
3. Sun Tolerance: Can also tolerate full sun if kept well-watered, although they still appreciate some shade during the hottest parts of the day. Also shade tolerant.
4. Drought Tolerance: Once established, they have good drought tolerance.

CONS

1. Can Be Floppy: Newer varieties are bred for stronger stems, because sometimes the huge flowers can cause the stems to bend over.
2. Deer love them: They love the leaves, and will eat the plants down to the ground if you let them.
3. Shorter blooming period: Smooth Hydrangeas generally have a shorter blooming period compared to some other types, lasting around 4-6 weeks.
4. Wilting: While they are drought tolerant, meaning they will survive dry weather, they do tend to wilt, especially in sunnier spots. This doesn’t harm the plant but it can be unsightly. They do perk up quick when watered, though.

Other Hydrangeas we Don’t Often Use

Understanding the downsides of the other types of Hydrangeas can help you make informed decisions about which plants are best suited for your garden and how to care for them properly.

Bigleaf Hydrangea (Hydrangea macrophylla)

This is one of the most commonly advertised hydrangeas, known for its large, rounded flowers that change color based on soil pH, with pink blooms in alkaline soil and blue blooms in acidic soil.

There are two main varieties of Bigleaf Hydrangea:

1. Mophead Hydrangea: large, globe-shaped flower clusters.

2. Lacecap Hydrangea: flat flower clusters with tiny fertile flowers in the center surrounded by larger sterile flowers.

Potted hydrangea macrophylla are also sold as floral gifts which can be enjoyed indoors temporarily. With proper care, they can be transplanted outdoors to continue growing.

PROS:

1. Flowers: Very showy flowers on compact plants and lots of different varieties to choose from.

CONS:

1. Flower color variability: Since the flower color is affected by soil pH, which is not easy to control in our more alkaline soils, achieving the desired color can be a challenge.
2. Cold sensitivity: Bigleaf Hydrangeas are more sensitive to harsh winter conditions, leading to damage or dieback in colder winters. We recommend our customers think of them more like a perennial.

Oakleaf Hydrangea (Hydrangea quercifolia)

Named for its oak-shaped leaves, this hydrangea type produces large, cone-shaped flower clusters. The blooms are typically white and can take on a pinkish hue as they mature. Oakleaf hydrangeas offer beautiful fall foliage colors, adding to their appeal.

PROS

1. Native to North America Showy foliage, flowers, and exfoliating bark on the older stems.

CONS

1. Deer love them: They will eat all the buds they can reach in winter and spring
2. Slower growth: Oakleaf Hydrangeas generally have slower growth compared to other types, which means it might take longer to establish in the landscape.
3. Cold sensitivity: Oakleaf Hydrangeas are more sensitive to harsh winter conditions compared to panicle types, and can have damage or dieback in colder winters.

Climbing Hydrangea (Hydrangea petiolaris)

Unlike other hydrangeas, this type is a vine that can climb walls, fences, and other structures. It produces flat, lacecap-like flower clusters and is ideal for adding a vertical element to the garden.

PROS

1. A showy, interesting form of Hydrangea.

CONS

1. Slow to establish: Climbing Hydrangeas can take several years to establish and start flowering after being planted, requiring patience.
2. Requires support: As a climbing vine, it needs a sturdy structure to grow on, which may not always be available in every space.

Mountain Hydrangea (Hydrangea serrata)

This type is closely related to Bigleaf Hydrangea and shares many similarities. They are generally smaller and more compact, with serrated leaves.

PROS

1. Compact, interesting plants.

CONS

1. Cold sensitivity: Similar to Bigleaf Hydrangeas, some Mountain Hydrangea varieties can be sensitive to cold and may suffer damage in harsh winters.
2. Pruning for reblooming: To encourage repeat blooming, it's essential to prune the faded flowers correctly, which can be time-consuming.

It's essential to consider your location, soil type, and sun exposure when selecting hydrangeas for your garden to ensure they thrive and produce beautiful blooms. Each type has its own unique characteristics, making hydrangeas a versatile and popular choice for gardens and landscapes.