Hydrangeas are primarily recognized as a source of summer color, but when left untrimmed until spring, their intriguing bark and flower heads may also add texture in the winter. Because of their generally coarse texture, they thrive in less formal gardens, perhaps at the property’s edge.
Hydrangeas can grow from three to fifteen feet tall and four to ten feet wide, depending on the species. They thrive on moist, fertile soil that receives full sun to partial shade. Long after the majority of shrubs have done blooming, hydrangeas produce huge white, pink, or blue panicles or clusters from June through August. Landscape plantings in Kentucky typically use four species.
KY Hydrangea SpeciesBig Leaf Hydrangea
The most popular variety of hydrangea in Kentucky is called Hydrangea macrophylla, or Big Leaf Hydrangea. White, pink, and blue can be found in its substantial blossoms. White cultivars stay white, but the availability of the micronutrient aluminum and the pH of the soil affect the color of pink or blue cultivars. Pink flowers are typically inspired by soil pH levels of 6 or above, whereas blue blooms are typically produced by soil pH ranges of 5.0 to 5.5.
In a greenhouse, specific Big Leaf Hydrangea cultivars are grown as potted plants in order to bloom in time for late-winter and early-spring events like Easter. These House Hydrangeas were chosen not for hardiness but for blossom size and simplicity of flower forcing. Without specific winter care, the majority of house hydrangeas planted in Kentucky landscapes won’t reliably produce flowers. The blossoms of the potted hydrangea are pink unless aluminum sulfate, which lowers pH and turns the flowers blue, is added to the potting medium or landscaping soil.
The majority of this species’ cultivars bloom on wood from the previous year. The blooms for the upcoming season will not survive if temperatures fall too low. With probable lows of -10 degrees, Kentucky is classified as zone 6. On occasion, extremely low temperatures destroy shoots or flower buds, preventing any flowering that year. Breeding efforts to enhance flowering characteristics have produced a number of new choices, such as “Endless Summer,” that will blossom on the growth of the current season and produce blooms even if late spring frosts damage the flower buds.
KY Hydrangea SpeciesSmooth Hydrangea
Large, white blossoms on new growth characterize Hydrangea arborenses, also known as the Smooth Hydrangea, which bloom every year from June through September. August will see a second flush of blossoms if the brown flowers are removed. It thrives in moist, well-drained soil with full sun to partial shade. In areas where the weather is typically hot and dry, some shade is optimal. This hydrangea can be used in smaller landscape locations because of its three to five foot height. There are a number of excellent cultivar options, but “Annabelle” is the most well-liked.
KY Hydrangea SpeciesPanicle Hydrangea
One of the bigger shrubs, Hydrangea paniculata or Panicle Hydrangea, can reach heights of six to ten feet and widths of six to ten feet, depending on the cultivar. In full sunlight, this plant will flourish. From June through September, enjoy the white to purplish-pink blossoms. When they start to turn brown or in the winter, blooms can be trimmed. This species’ “Limelight,” which has big, light green blossoms that develop to white, is a well-liked choice.
KY Hydrangea SpeciesOak Leaf Hydrangea
The Oak Leaf Hydrangea, or Hydrangea quercifolia, is a popular landscape plant for locations with part shade and is a native of the southeastern United States. It is renowned for its big, oak leaf-shaped foliage. With panicles that are three to four inches broad, the white to purplish-pink flowers range in length from four to twelve inches. There are many of fragrant flowers. The foliage changes to reddish, orange-brown, and purple hues in the fall, bringing more color to the environment. The Oak Leaf Hydrangea does best as a border planting in partial shade.
Growing Hydrangeas in Kentucky
Give these four common Kentucky hydrangea types a spot that will receive full sun to part shade to get the most out of your planting. Drought stress and scorching heat are lessened by afternoon shade. Don’t prune in the autumn. After the shrub has flowered in the summer, prune to give it time to develop new flower buds for the following season before winter arrives.
The book Hydrangeas for American Gardens by Michael A. Dirr, published by Timber Press, is a wonderful source for more information (2004).
Oldham County Horticulture Assistant Michael Boice contributed the writing. Lauren State, an assistant with the Oldham County Extension, edited the text.
KENPAI, Frank Vincentz, and Anne Norman all contributed photos. the Creative Commons Attribution license is used.
Which month do you prune back hydrangeas?
Depending on which group the plant belongs to, the timing and extent of pruning are determined:
Advice on Pruning for Group 1:
- As the days get shorter and the weather gets colder in the late summer and fall, buds for the following year’s blooms start to form.
- Typically, removing dead, diseased, or damaged branches is all that is required to preserve shape, size, and a healthy plant. Otherwise, gentle pruning ought to be practiced.
- In the summer, trimming should begin as soon as flowering ends, but no later than August 1. Pruning should not be done in the fall, winter, or spring because you risk removing fresh buds.
- Tip-pruning the branches in the spring as the leaves begin to appear can promote more numerous, smaller flower heads as opposed to fewer, larger flower heads.
Advice on Pruning for Group 2:
- On the growth of the current year, flower buds form.
- Early in the spring, as the leaves are starting to emerge, prune.
- Just above a node, prune branches back by half to a third.
- After that, prune any fragile or spindly branches.
- Minimal trimming encourages huge, strong bushes with many of tiny flower heads in H. arborescens. Hard pruning between 12 and 18 inches from the ground, or even all the way down, will result in fewer but larger flower heads that may flop if unsupported.
- For H. paniculata, remove the surrounding smaller wood while leaving the larger stems in order to establish a sturdy foundation.
Pruning may be connected to flower head size. Shoots will grow more vigorously and flower heads will be bigger and fewer with more rigorous trimming. Smaller but more numerous flower heads may result from less aggressive or tip pruning.
Consideration of hydrangeas’ mature size is the best piece of advise. Place them in a location where they won’t outgrow and won’t need a lot of pruning to keep them in check. Hydrangeas don’t need to be pruned precisely or often; as long as dead wood is removed, they will remain healthy and continue to develop and bloom.
Cut back these shrubs in late winter before new growth begins
Shrubs that flower on young wood typically start blooming later than old-growth bloomers, beginning in June and continuing until the first frost, because they need to grow and set buds the same year that they bloom. As long as you avoid trimming when the flower buds are opening, these shrubs are understanding if it is not done at a specific period.
1. Trim the flowers all the way back for larger blooms.
These bushes can be completely removed from the ground in late winter or the beginning of spring. If cut severely like this every year, smooth hydrangeas will produce much larger flowers, but many gardeners prefer smaller blooms on stronger stems.
2. Maintain an old growth foundation to lessen flopping
Especially after watering from above or after a heavy storm, the branches of some hydrangeas frequently topple over from the weight of their blooms. Cutting the stems to a height of 18 to 24 inches will help to reduce this flopping by creating a strong framework for fresh growth.
Janet Carson is the University of Arkansas Cooperative Extension Service’s horticulture specialist.
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Do hydrangeas need to be pruned before winter?
It’s not necessarily necessary to severely prune your hydrangeas (Hydrangea spp.) before putting them to bed for the winter. Depending on the cultivar, hydrangeas can be grown in USDA plant hardiness zones 3 through 9, with each variation having different pruning requirements. Before you grab the shears, you must identify the type of hydrangea to know how far back to cut it for the winter.
Tip
Depending on the variety, hydrangeas can bloom on either old or new wood. Old-wood blooming hydrangeas need to be pruned just after the flowers fade in the late summer, whereas new-wood blooming hydrangeas should be pruned in late winter before new growth begins.
Should hydrangeas be pruned annually?
You can prune the first pair of buds on Hydrangea macrophylla, Hydrangea serrata, Hydrangea quercifolia, and Hydrangea aspera in the spring. In essence, you are removing the dried flower heads. By removing one or two of the oldest, largest stems, you can also help the plant become more open and give off a better shape. To promote fresh growth, cut these right back to the ground.
Hydrangea aborescens and Hydrangea paniculata can be clipped back more severely after flowering since flowers appear on fresh growth. These kinds don’t truly require pruning, although you can do it to prevent them from becoming too tall.
Should hydrangeas be pruned in the fall?
When do you prune? Only prune these hydrangeas in the summer after bloom, not in the fall. In August and September, old wood hydrangeas begin to form their bloom buds for the following year. It is advisable to delay pruning your hydrangeas until the following year if you don’t do it right away.
Which hydrangeas ought to be left alone?
Here are several common hydrangea varieties and when to prune them:
- The most popular species of big-leaf hydrangeas, Hydrangea macrophyla, are the well-known mopheads and lacecaps, which come in a variety of shades including blue, violet, pink, purple, red, and white. After flowering, trim them since they blossom in the early summer on old wood.
- Hydrangea quercifolia, sometimes known as oakleaf hydrangea, is a native hydrangea with cone-shaped white blooms that turn a stunning shade of russet in the late summer. It too blooms on old wood, thus pruning shouldn’t be done before flowering.
- Panicle hydrangeas, Hydrangea paniculata: These shrubs (Tardivas, PeeGees) burst into panicle-shaped white flowers in mid- to late summer and are frequently pruned into tree forms. Prune these in the early spring before they produce new foliage since they blossom on fresh wood.
- Hydrangea arborescens, ‘Annabelle’: This variety flowers on new wood as well, so prune in early spring. In the spring, the globe-shaped blooms start out chartreuse and gradually turn white.
recurring, or “Reblooming hydrangeas: This unique breed of hydrangeas was developed to bloom multiple times throughout the growing season. They come in a variety of colors, and “Endless Summer” is one of the most well-known cultivars. This means that these hydrangeas can be pruned at any time because they bloom on both old and new wood.
Remove any dead branches and limbs from a hydrangea that blooms on old wood before thinning down the center of the plant to allow more sunlight to enter. The Tardiva and PeeGee types, which flower on fresh wood, can be trimmed judiciously by removing branches that don’t conform to the plant’s desired shape or regulate size. The most extreme haircuts are available for ‘Annabelle’ hydrangeas, which can have their entire shrub cut back to six to twelve inches above ground.
Do you now comprehend why the query “One of the biggest mysteries in gardening is when to prune my hydrangeas.
In the fall, what should I do with my hydrangeas?
Maintaining your hydrangea can greatly impact its blooms the next year. When given enough time and the right care, hydrangeas are resilient and can recover from virtually anything.
See our comprehensive growth guide for hydrangeas here after reading the fall maintenance advice below!
Because some hydrangea kinds do not like to be clipped in the fall, it is crucial to first identify your variety.
If you have hydrangeas in your garden, you should be aware that there are two different varieties. Both types develop blossom buds, one on new wood and the other on old wood. If a stem has remained on the plant since the previous summer, it is referred to as old wood. Stems that form this season are considered new wood. The majority of hydrangea species that are found in gardens are old wood bloomers, including as Mophead, Big Leaf, Lacecap, and Oakleaf types. Check your variety once more at the neighborhood garden center.
Hydrangeas can grow for many years without being pruned, but it’s time to cut them if they become unkempt, take over a portion of the garden, or stop producing new growth. But when should they be pruned?
After the summer blooms on old wood bloomers or fall blooming hydrangeas, prune them. Old, woody hydrangeas that are pruned in the fall will not bloom the following season.
Hydrangeas that bloom in the summer or those that do so on fresh wood are clipped in the fall, after their flowering season has ended.
Early in the season, hydrangeas are brilliant and colorful, but they are difficult to preserve after being cut. Once they begin to dry on the bush, they are simpler to maintain.
Your plant will have weak, wispy growth near the bottom. Reduce them. They will consume energy that could be used by your plant to produce blossoms.
On your stems, look for any dead stumps. They won’t have sprung any buds or new wood from the original old wood. To totally remove the dead stumps, cut them to the ground at the base. This will give the new growth below a chance to flourish.
To make way for new buds to emerge, old and dead blossoms must be eliminated. To promote flowers for the following summer, remove the flower head immediately above the first few leaves.
Observe the plant’s shape from a distance. The shrub should be pruned into the shape you desire; a spherical is the traditional shape, but you can prune it however you like!
Clean up any leftover debris from the plant’s foundation. Make sure your soil is devoid of all weeds, dead flowers, and leaves.
Feed your blue hydrangeas with Holly-tone to maintain acidic soil and vibrant flowers. Alternatively, choose Flower-tone.
Feed your hydrangeas two to three times each week from spring till fall for the greatest results.
Your hydrangeas will remain healthy and vibrant for many years if you follow these simple instructions.