Introduction to Hydrangeas

Hydrangeas, beloved for their lush, vibrant blooms, are a staple in many gardens worldwide. These flowering plants belong to the Hydrangea genus, which is part of the Hydrangeaceae family. With over 75 species and numerous cultivars, hydrangeas offer a wide range of varieties, each with its unique characteristics in terms of bloom size, color, and growth habit. Understanding the different varieties can help gardeners choose the best hydrangeas for their specific needs and growing conditions.

Popular Hydrangea Varieties

Among the many varieties of hydrangeas, some stand out for their popularity and versatility. The 'Annabelle' hydrangea (Hydrangea arborescens 'Annabelle') is renowned for its large, spherical, white blooms that can reach up to 12 inches in diameter. Another popular choice is the 'Endless Summer' series (Hydrangea macrophylla 'Endless Summer'), which includes several cultivars known for their ability to bloom on both old and new wood, extending the flowering season.

Hydrangea Macrophylla Varieties

Hydrangea macrophylla, commonly known as bigleaf or French hydrangeas, are perhaps the most iconic varieties. They are prized for their large, showy blooms that can be either mophead or lacecap in form. Mophead hydrangeas feature rounded flower clusters, while lacecaps have a flat-topped flower head with a center cluster of small, fertile flowers surrounded by larger, showy, sterile flowers. Some notable macrophylla varieties include 'Nikko Blue', 'Bailmer', and 'Mathilda Gutges'.

Hydrangea Arborescens Varieties

Hydrangea arborescens, or smooth hydrangeas, are known for their large, white or greenish-white blooms that appear in late spring to early summer. These hydrangeas are native to North America and are characterized by their upright growth habit and ability to tolerate shade. Popular arborescens varieties include 'Annabelle', 'Incrediball', and 'Invincibelle Spirit'.

Hydrangea Quercifolia Varieties

Hydrangea quercifolia, commonly referred to as oakleaf hydrangeas, are distinguished by their unique oak-shaped leaves and impressive, cone-shaped blooms that turn from white to pinkish-brown as they age. These hydrangeas are native to the southeastern United States and are prized for their exceptional fall color and attractive peeling bark. Notable quercifolia varieties include 'Snow Queen', 'Alice', and 'Sikes Dwarf'.

Hydrangea Paniculata Varieties

Hydrangea paniculata, or panicle hydrangeas, are known for their large, conical flower heads that can reach up to 12 inches long. These hydrangeas are hardy and versatile, tolerating a wide range of growing conditions. They are also notable for their ability to be pruned into tree form, making them a striking addition to any landscape. Popular paniculata varieties include 'Grandiflora', 'Limelight', and 'Tardiva'.

Hydrangea Serrata Varieties

Hydrangea serrata, or mountain hydrangeas, are similar in appearance to Hydrangea macrophylla but are more compact and better suited to cooler climates. They feature lacecap-style blooms that can be blue, pink, or purple, depending on the soil pH. Notable serrata varieties include 'Blue Billow', 'Amacha', and 'Mariesii'.

Conclusion

Hydrangeas offer a diverse range of varieties, each with its own charm and characteristics. From the iconic bigleaf hydrangeas to the hardy panicle varieties, there is a hydrangea suitable for every garden and growing condition. By understanding the differences between these varieties, gardeners can make informed choices and create stunning displays of color and texture in their outdoor spaces.

Questions and Answers

1. What is the difference between mophead and lacecap hydrangeas?
- Mophead hydrangeas have rounded flower clusters, while lacecaps have a flat-topped flower head with a center cluster of small, fertile flowers surrounded by larger, showy, sterile flowers. 2. Which hydrangea varieties are best for shade?
- Hydrangea arborescens varieties, such as 'Annabelle' and 'Incrediball', are known for their ability to tolerate shade. 3. Can hydrangeas be pruned into tree form?
- Yes, Hydrangea paniculata varieties, such as 'Grandiflora' and 'Limelight', can be pruned into tree form, creating a striking visual impact in the garden. 4. What determines the color of hydrangea blooms?
- The color of hydrangea blooms is influenced by the soil pH. Acidic soil tends to produce blue blooms, while alkaline soil results in pink or purple blooms.

In summary, hydrangeas are a diverse group of plants with numerous varieties, each offering unique features in terms of bloom size, color, and growth habit. Understanding these differences can help gardeners select the perfect hydrangeas for their gardens, enhancing the beauty and diversity of their outdoor spaces.