New versus Modern Hydrangea Species and their Water Needs Clarified
Hydrangeas, a popular garden plant, boast an impressive variety that catches the eye of any gardener. Their beautiful blooms and elegant foliage are coveted during the summer season. However, sometimes these captivating plants fail to bloom. Surprisingly, mismanaged pruning often plays a significant role in these bloomless situations. Yet, not all hydrangeas require the same pruning techniques. These garden delights fall into two primary categories: old wood and new wood hydrangeas. Comprehending this distinction is key to unlocking the secrets of hydrangea pruning and maintaining a bloom-filled garden year after year.
The terms old wood and new wood refer to plants that produce flowers on last season’s growth (old wood) or the current year’s growth (new wood). Pruning hydrangeas becomes a straightforward task once you identify your plants' respective pruning groups and the appropriate time to prune. This guide details the significant differences between old and new wood hydrangeas, common species, and essential pruning practices for each group.
Old Wood Hydrangeas
Hydrangea species that flower on old wood produce buds on stems that grew during the previous growing season. These dormant flower buds burst into bloom the following spring or summer. Pruning these old shoots during the dormant season would eliminate the flower buds, resulting in a flowerless garden for the year. Deer browsing and late spring freezes are other reasons that plants may fail to bloom, but they are beyond human control. With that in mind, tweaking pruning practices can encourage blooming.
Many popular hydrangeas belong to the old wood category, including the beloved bigleaf hydrangea (Hydrangea macrophylla). These Southern Belles are known for their large, shiny leaves and color-shifting blooms, which can vary based on the soil pH. They are further divided into two main groups, mopheads, and lace-caps.
Oakleaf hydrangea (H. quercifolia) is another old wood species with attractive foliage and large cone-shaped blooms. Native to southeastern woodlands, oakleaf hydrangeas display vibrant fall colors and bark that sheds during the winter season. Less common old wood species include mountain hydrangea (H. serrata), which showcases lovely lacecap blooms, and the climbing hydrangea (H. anomala).
The optimal time to prune hydrangeas that flower on old wood is during the summer, following their blooming period. In general, old wood hydrangeas require minimal pruning. Lightly pruning oakleaf, climbing, and mountain hydrangeas is an excellent way to shape your plants after they have finished blooming. Simply trim back branches to a healthy bud. Consider cutting back stems that cross or rub against one another. Climbing hydrangeas grow vigorously and may require more extensive pruning to keep them confined to their trellis. Dead or damaged branches can be removed throughout the year.
variety of hydrangeas available at garden centers speaks to their popularity. Gardeners adore the billowy blooms and elegant foliage they bring to the summer garden. But sometimes hydrangeas fail to bloom. You may be surprised that improper pruning commonly plays a role. Not all hydrangeas are alike. The group includes several species that fall into two distinct
Big-leaf hydrangeas can be pruned more aggressively. During the growing season, they produce flowers on old stems while also growing new shoots from the plant's base or crown. To encourage the growth of larger blooms on sturdy shoots, decrease the number of stems from established big-leaf hydrangeas each season. Remove up to one-third of the stems, cutting them back to the base. Keep several stems of productive old wood, as well as strong new shoots that will bloom the following season. Old stems appear stiff, with a grey or brown color, while new shoots are softer, more flexible, and bright green.
New Wood Hydrangeas
Hydrangeas that bloom on new wood produce buds on tender, emerging shoots in the spring. Flowers typically burst into bloom a few months later, during the summer. Because buds do not exist during the winter months, these varieties are less susceptible to freezing temperature damage to their buds.
pruning groups: old wood and new wood hydrangeas. Understanding this key difference will take the mystery out of pruning hydrangeas and ensure your plants bloom year after year.
Panicle hydrangea (H. paniculata) and smooth hydrangea (H. arborescens) are commonly grown new wood species. Panicle hydrangeas are exceptionally well-adapted to the hot and humid summer climate of the Deep South, making them some of the easiest hydrangeas to grow. They often feature oversized blooms, which start white or green and mature to pink or burgundy hues.
Smooth hydrangeas are native to the southern US and produce large flower heads, up to a foot in diameter. Many people mistakenly call smooth hydrangeas by their cultivar name 'Annabelle,' an older but enduringly popular variety. A wide selection of new cultivars now offers white, pink, or green flower heads.
New wood hydrangeas are typically pruned during the winter or early spring, when the plants are dormant. Although pruning is not strictly necessary, it is commonly used to control plant size and promote stronger stems and bigger flower heads. Scaffold pruning is a beneficial technique for both species, which involves retaining a structure of old stems to support new growth.
Since pruning occurs during the dormant season, all existing stems can be considered old wood. Start by removing the weakest stems, cutting them back to ground level to make room for new growth and improve airflow throughout the canopy. Maintain several stems to create your framework, cutting these back to varying lengths, from one to two feet above ground level. Remove any stems that cross or appear dead or damaged. There is no need to worry about removing buds through this aggressive pruning, as they have not yet formed.
- For old wood hydrangeas like the bigleaf hydrangea (Hydrangea macrophylla), the optimal time to prune is during the summer after their blooming period, requiring minimal pruning with light trimming to shape the plants.
- Understanding the distinction between old wood and new wood hydrangeas is crucial for pruning these garden delights effectively, as mismanaged pruning can lead to bloomless situations.
- SouthernLiving provides a variety of hydrangeas available at garden centers, highlighting their popularity and the desire for beautiful blooms and elegant foliage in the summer garden.
- Articles under the 'Gardening Ideas' section of SouthernLiving's 'block_8' feature information about old and new wood hydrangeas, their pruning techniques, and essential gardening tips.
- Lazyload techniques are used to optimize the loading of articles comparable to 'SouthernLiving's article__broad about gardening flowers' on the website, ensuring a seamless browsing experience for users.
