For homeowners, hydrangeas are a popular shrub. They produce a magnificent show in gardens from mid-summer till fall. They are adaptable shrubs that do well in both shady woodland areas and sandy coastal soils.
Bigleaf hydrangeas (Hydrangea macrophylla) and mountain hydrangeas are typically what come to mind when we think of hydrangeas (Hydrangea serrata). Japanese seacoasts and mountain valleys are home to these deciduous shrubs, which are classified into two varieties based on the appearance of their blossoms. Large, ball-shaped flower clusters are characteristic of mop-head varieties (also known as hortensias). The fertile blossoms are frequently concealed behind these barren flowers. The sterile flowers are located on the outer margins of the flat, delicate clusters of lace-cap kinds, while the fertile blooms are positioned in the center. The majority of hydrangea varieties can produce either mophead or lace-cap flower styles, depending on the ratio of fertile to sterile flowers for a given cultivar. Only lace-cap blooms are present on Hydrangea serrata.
These bushes grow 3 to 6 feet tall and are hardy in zones 5 through 9. Despite the lengthy guidelines for carefully trimming hydrangeas, the majority don’t require any pruning to thrive. You can avoid spending countless hours pruning if you choose a location that can accommodate the entire growth of your chosen cultivar. Simply trim away any dead branches you see.
The east side of a house is frequently a wonderful choice for planting since it provides morning sun and diffused sunshine in the afternoon for your hydrangea. In well-drained soil that has been supplemented with organic matter, they pose few difficulties. Lack of flowers is the primary issue that gardeners encounter.
Shade
Too much shade is one typical factor in the absence of blooms. Tall deciduous trees that give partial shade are beneficial to hydrangea growth. Choose a location for your hydrangeas where they will get morning sun. They also do well in direct sunlight, however on hot summer days they can need more water. Once established, bigleaf hydrangeas can tolerate full sun in coastal locations.
Care
Sometimes a paucity of flowers is a result of cultural customs. Hydrangeas may develop luxuriant foliage without many flowers if plants get excessive amounts of high-nitrogen fertilizer. Your hydrangea bed may become contaminated by fertilizer used on lawns, which will result in the same issue.
For healthy plants, it’s also critical to use proper irrigation techniques. In the summer, hydrangeas require one inch of water per week. During the hottest summer days, bigleaf hydrangeas in full sun may require up to 2 inches every week.
Cold winters
In colder areas, winter dieback can be an issue. Verify the winter hardiness of the hydrangea you have chosen in your USDA growing zone. Because the roots will be more exposed if you keep your hydrangea in a container, it must be hardy in one or two zones cooler than the one in which you live.
As winter comes, try planting your hydrangeas in a protected area or building a burlap windscreen or burlap frame filled with dried leaves. A property with a north or east face tends to have more consistent winter temperatures. Your property’s south and west sides will heat up in the winter sun, which could lead to hydrangea buds opening too soon. A hardly noticeable spring freeze can potentially destroy budding buds.
Pruning at the wrong time
The main reason why there aren’t any flowers is improper pruning. On aged wood, bigleaf hydrangeas bloom. Although they only require occasional pruning, the optimum time to prune these shrubs if you want to minimize the size of the plant is right after flowering. If, however, the branches’ tips are killed by chilly winters, prune in the spring. Cut the stems back to a healthy set of buds and remove any dead wood before the hydrangea begins to leaf out. You can also remove a number of the older stems now if your shrub is already established. This will lessen traffic and promote fresh growth. To prevent losing your flowers, be careful not to pluck too many buds. When you trim mop-head and lace-cap hydrangeas in the spring, the buds have already developed, and every piece of stem you eliminate diminishes blossoming.
See the Types of Hydrangeas link at the top of this page for details on trimming various hydrangea species.
The relationship of soil pH to hydrangea flower color:
The amount of aluminum in the soil as well as the pH of the soil affect the color of bigleaf hydrangea blooms in addition to the specific cultivar. How readily available aluminum is to the plant will depend on the pH of the soil. Given that plants can access aluminum in acidic soil, blue flowers will result, while pink blooms will result from alkaline soil (aluminum unavailable to the plants).
Add hydrated lime to your soil in the spring to reduce soil acidity (to make blooms become pink instead of blue). Add aluminum sulfate to your soil in the spring to raise the acidity level (flowers will turn blue instead of pink as a result; read label instructions carefully and don’t overdo it). The three digits on your fertilizer, on the other hand, should be taken seriously. Phosphorous is the middle number. While fertilizers with low phosphorus and high potassium can help color your hydrangeas blue, high phosphorous will assist trap the aluminum in the soil and give you a pink variety.
Warning:
Some hydrangeas won’t change their color no matter what you do, and changing their color is not always simple. On the other hand, if you vary the pH of the soil, some of them will change their color and may even give you both pink and blue flowers in the same season.
There is a beautiful variety of additional varieties available for the home gardener to chose from in addition to the bigleaf and mountain hydrangeas, which are perennial favorites. To learn more about some additional popular cultivars and common hydrangea species, click the Types of Hydrangeas link at the top of this page.
What time of year should I trim my hydrangea?
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.
When cutting back hydrangeas for the winter?
If and when you prune is the key to happy, healthy hydrangea flowers. Of course, fertilizing and offering the ideal environment have a lot to recommend them. However, if you don’t prune properly, your efforts will be in vain. Deadheading is not the same as trimming. Pruning refers to more drastic cutting to preserve shape or remove dead growth. However, feel free to discard spent blossoms or cut fresh ones to use in arrangements.
Hydrangeas can bloom on either fresh wood or old wood, depending on the species. The wood from which they blossom determines whether and when to prune.
Old wood-blooming hydrangeas do not require pruning and benefit from it. They’ll blossom more abundantly the next season if you leave them alone. But feel free to deadhead or gently thin. Just keep in mind that while new growth may appear, it won’t bloom until the following season. In our region, four different species blossom on aged wood. Additionally, they are not limited to the hues displayed here.
Climb using suckers. On your wall or trellis, resist the desire to remove the dormant growth.
The flower heads are more conical in appearance, and the leaves are large and resemble oak leaves. It’s a pleasant surprise for a hydrangea when its leaves turn reddish-orange in the fall.
They are very comparable to lacecap types, but smaller and with more compact leaves.
Pruning should be done in late winter or early spring on hydrangeas that bloom on new wood. Trim back to two feet to prune to shape. The next season’s blossoms are produced by strong, fresh growth that is encouraged by trimming. In our region, there are two types that bloom on fresh wood. They are also not restricted to the colors displayed.
Oakleaf variants are not included in cone-shaped blooms. Keep the blooms on throughout the winter to provide interest; even dried out, they are quite lovely.
regarded as a wild kind. They often have smaller blooms and leaves than Bigleaf variants and are completely white. They enjoy full sun and can grow very tall.
Knowing whether or when to prune now will help you avoid the disappointment of a hydrangea that doesn’t blossom. Don’t forget that a robust shrub will produce more gorgeous blossoms if it has well-draining soil and good organic fertilizer. Come on in, and we’ll show you where to go to develop your green thumb.
In the fall, how far back should hydrangeas be pruned?
Trimming season for hydrangeas that bloom on new wood runs from late fall through early spring. This group includes smooth and peegee forms, which function well whether they are pruned lightly, to the ground, or not at all. In order to maintain a compact stature and luxuriant flowering, Peegee hydrangeas are frequently pruned into trees with one or two main stems that are between 15 and 30 feet tall.
Smooth hydrangeas can be pruned all the way to the ground; however, the more frequently they are cut, the less able their stems are to withstand the weight of their huge blooms. Smooth hydrangeas grow in mounds that are 3 to 6 feet tall and wide. When the plants are pruned to leave between 18 and 24 inches of growth, a woody base forms that helps the stems support the pompom blooms more effectively.
What occurs if your hydrangeas aren’t pruned?
I’m curious if trimming my panicle hydrangea in the fall is actually essential. What will happen to the flowers the following year if I keep them outside all winter, even after they have turned beige? Will they inevitably lose their grip?
Answer: The panicle hydrangea (Hydrangea paniculata), a giant shrubby hydrangea with dense conical clusters of flowers that are white as they open and turn darker and deeper pink as the season progresses, doesn’t have anyone to prune it in nature. The blossoms then become beige due to the effects of frost and survive all or part of winter before gradually disappearing as new growth starts to appear in spring. If any dried blooms are left thereafter, they are swiftly masked by new leaves that cover the bush.
I never perform a fall pruning on my panicle hydrangeas. They have a truly amazing winter effect, especially in the snow. I don’t understand why people feel the need to cut back this shrub in the fall and destroy all of its lovely blossoms, leaving only a collection of brown stalks with their tips trimmed off as a winter decoration. Even gray flowers, in my opinion, are preferable than having no flowers at all, especially in the winter.
If you need to prune your panicle hydrangea—which can grow enormous over time, reaching up to 15 feet (5 m) in height and spread if you never cut it back!—you should do so in the early spring, right after snowmelt. If you want to significantly reduce its size, cut the plant almost all the way to the ground. The new branches that grow shortly after this early spring cutting will still blossom flawlessly from late summer onward, guaranteeing another fall of beauty since it blooms on new wood.