Some trees and shrubs should be pruned in the late winter. The hydrangea is one plant that many gardeners find difficult to grow. It’s simple to become perplexed about when and how to prune because there are several varieties of hydrangeas accessible, each of which blooms and grows in a distinct way. I’ll share some advice with you on how to prune three popular hydrangea varieties.
The smooth leaf hydrangea, or Hydrangea arborescens, is a well-known variety. The most popular cultivar of this hydrangea is Annabelle. Depending on the cultivar, it blooms in the early to midsummer with either pink or white flowers. In order to encourage new growth and more flowers, smooth leaf hydrangeas should be pruned immediately to the ground or around 1 foot tall.
Beautiful blue hydrangeas include the big leaf variety, Hydrangea macrophylla. Depending on the acidity of the soil, it has magnificent blue, red, or pink blooms that bloom from the middle of the summer until the end of the season.
Newer variations of this type of hydrangea bloom on spring-growing new branches as well as on older branches that have survived the winter. After the initial flowering burst in the middle of summer is the optimal time to prune. Just prune old blossoms and reduce crossed or crowded branches.
The common shrub or small tree type of hydrangea is called the panicle, or Hydrangea paniculata. It blooms in pink, crimson, or white. Fall and late summer are when it blooms. It blooms on new growth from the spring, just like the smooth leaf hydrangea, so prune now to shape the plant, get rid of crowded branches, and encourage new growth that will ultimately flower.
In CT, how long do hydrangeas bloom?
The spectacular clusters of flowers on hydrangeas, a deciduous woody ornamental shrub or climber plant, come in a wide range of colours, including white, lime green, pink, purple, and blue. They are a well-liked shrub for New England settings because they can withstand USDA zone 6 and some types can withstand USDA zones 5 or 4.
varieties of hydrangeas The information for each variety of plant can be found in the UConn Plant Database by clicking on the links that are underlined.
Climbing hydrangea, also known as Hydrangea anomala subsp. petiolaris. An Asian native, this hydrangea is a climbing woody vine. Although there will be fewer flowers in complete shade, it can withstand full sun, medium shade, and full shade and has fragrant white lacecap blossoms. It can be planted on a building’s north or east side, and with to its aerial roots, it will adhere to nearly any solid framework or support. In June and July, flowers bloom. After establishing itself, it can eventually reach heights of 30′ and a width of 8′. Zone 4 hardy. resistant to deer.
The ‘Annabelle’ and ‘Grandiflora’ types of Hydrangea arborescens, sometimes known as smooth hydrangeas, with spectacular white, pink, or green umbellate corymbs that bloom from May to July. They can grow to be 5′ tall and broad. frequently grown as a hedge. Can tolerate some shade and is hardy to zone 4.
A typical variety of hydrangea growing in New England is Hydrangea macrophylla, also referred to as the mophead or bigleaf hydrangea. These hydrangeas have broad, spherical snowball-shaped blue, purple, fuchsia, or light pink flower heads. Bigleaf hydrangeas with lacecaps (Hydrangea macrophylla var. normalis) contain corymbs of tiny fertile flowers surrounded by bigger, more ornamental sterile blossoms. Zone 6 hardy.
panicle, PeeGee, or hydrangea paniculata. This native hydrangea to North America is grown as a big shrub or small tree and features huge, cone-shaped panicle flower heads with fragrant white, pink, or lime-green blooms. Mid-July to early-September is when it blooms. This type prefers direct sunlight over light shade. Zone 3 is hardy.
Oakleaf hydrangea, also known as hydrangea quercifolia, produces upright pyramidal clusters of white blooms. The autumnal leaves, which resemble an oak leaf in form, become red-purple. It has an 8′ maximum height. Zone 5 hardy, but flower bud damage is possible.
Choosing a Site and Planting The variety may affect the choice of site. Climbing hydrangea may reach 30′ and will require sturdy support. If not cut to maintain height, Hydrangea arborescens, H. quercifolia, and H. paniculata can reach heights of 8 to 10 feet and are best used as backdrop or hedge plantings. The most popular variety of hydrangea used in landscape beds, growing from 3 to 6 feet tall, is hydrangea macrophylla.
All hydrangeas should be planted in soil that is healthy, well-drained, and rich in organic matter. Before planting, it is advised to get your soil tested by the UConn Soil and Nutrient Analysis Lab, especially if you intend to keep your H. macrophylla’s pink or blue blossoms.
All hydrangea need 6 to 8 hours of direct sunlight each day to produce their most numerous flowers. A much of shadow will hinder or stop flowering. In hot areas, hydrangea are shade resistant and even prefer afternoon shade, but heavy shadow, like that found beneath a big tree or on a building’s north side, won’t provide enough light for flowering. The best hydrangea for hot regions is oakleaf, which grows well in full sun or partial shade. If it gets more sun, the leaves will be more vibrant.
For general information, see our fact sheet Tree and Shrub Planting Guidelines.
Water When the weather is typical, hydrangea only need one week’s worth of water, but when it’s hot and dry, they need two. It is advised to utilise soaker or drip hoses for one or two extended soaks per week. Continuously wilting hydrangea will become stressed and may have fewer bloom buds the following year. If you can, avoid watering the leaves to reduce the risk of leaf spot illnesses. Water the hydrangeas regularly until the ground freezes.
Feeding and pH of the Soil Late spring and mid-summer are the best times to use a 5-10-10 slow-release fertiliser, but not after August 15. The majority of hydrangeas thrive in slightly acidic soil. Because of the soil’s lower pH, in the 4.0 to 5.0 range, Hydrangea macrophylla may access the aluminium ions and produce blue flowers. The pH of the soil must be increased to 6.0–7.0 in order to bind aluminium ions in the alkaline soil and produce pink blooms. The information on amendments required to implement those adjustments will be obtained through a soil test.
Hydrangeas may become iron-deficient if the pH of the soil is too high. Younger leaves with yellowing between the veins are a sign of this. Older leaves that are yellowing are probably nitrogen deficient. Iron in the form of iron chelate can be added to the soil as a temporary fix without reducing the pH. Lower the soil pH with an aluminium sulphate or sulphur product for a longer-lasting fix. Pay close attention to the directions on the product label for either strategy.
Maintenance and Care The failure of hydrangeas to produce blooms is one of their most frequent problems. The most frequent causes of this are trimming techniques or winter/frost damage. During a warm spell in the late winter or early spring, flower buds may start to emerge from dormancy; however, the cold conditions that follow might cause their death. Hydrangea that bloom on old wood can be shielded from this issue by enclosing the plant in a cage made of cylindrical wire mesh and covering it loosely with mulch or leaves. As the material settles, add more. When the threat of a fatal frost has gone, remove mulch.
Popular Easter and Mother’s Day presents include potted hydrangeas from florists. It can be planted outside in a protected area once the flowers have faded and the risk of frost has passed. Since they were produced in greenhouses with an emphasis on producing luxuriant blooms, these hydrangeas (often H. macrophylla) are typically not as winter-hardy as plants that were grown in nurseries. Flower buds might not make it through the winter. Try the following to increase your chances of successfully overwintering: Trim to 3 to 5 inches above the ground around the Fourth of July. The plant will grow again with terminal flower buds dormant. Place a screen around the plant before it gets colder than 25 degrees Fahrenheit, and fill it with insulation like coarse peat moss, vermiculite, or bark mulch. In the event that it settles throughout the winter, add more material. When the crocuses bloom in the spring, take the covering off, but keep it on during the colder nights.
When the hydrangeas are dormant is the ideal time to transfer them (after all leaves have been shed). As much of the root ball as you can, dig up. After transplanting, water thoroughly, and then frequently for the first two summers. Watering deeply less frequently is preferable to watering every day.
- Early June is the ideal time to start stem cuttings.
- Take a 5- to 6-inch clipping from a stalk without flowers.
- Remove all leaves except the top few.
- To lessen the need for water when the plant is roots, increase the size of the leaves by roughly half (cut perpendicular to the mid-vein) (see illustration on below left).
- The cuttings are placed in a moist mixture of half peat or potting soil and half fine-grade perlite, vermiculite, or sand after being dipped in a rooting hormone.
- Put two or three of the cuttings in the ground. Spray the clippings with water to hydrate them.
- Keep the soil damp but not drenched.
- Enclosing the cuttings in plastic is a fantastic strategy to keep moisture in during the roots process (see illustration on below right).
- To keep the plastic from contacting the leaves, stakes can be utilised.
- Place between 60 and 80 degrees Fahrenheit in a bright, shaded place.
- In around two weeks, new growth should start to show.
- After four weeks, plants are ready for transplant.
- In order to promote roots, a branch from the plant that is still attached is buried in the earth.
- Remove all the leaves from the portion of the branch that will be buried by choosing one that is close to the ground.
- Remove a small amount of bark from the branch’s underside.
- Because roots grow best in the buried area, make sure there is at least one leaf node there.
- Create a trench that is about two deep and the length of the branch’s leafless portion.
- Put the branch in the trench, then completely cover it with water.
- The branch will stay in place and assist retain moisture if a brick or stone is placed on freshly moistened soil.
- When roots are given some water, they will grow.
- Transfer the rooted branch to a pot after removing it from the mother plant.
- It may be more successful to transplant the new branch if it is severed from the mother plant (after roots have formed) and left in the ground unattended for a few more weeks.
Flower Preservation and Drying The right time of harvest is the most crucial element in the effectiveness of drying hydrangea. The easiest way to dry blooms is to let them partially dry on the plant before picking them. Consider harvesting between August and October. The blossoms will have a vintage appearance as they get older. Cut the flowers, remove the leaves, arrange the flowers in a vase, and then let them dry. Except in cases where the stems are flimsy and weak, they do not require hanging upside down.
The following guidelines for pruning hydrangeas apply to all varieties:
In the first two to three years as it establishes, avoid pruning. If sprouts are developing outside the desired area after the blooming season, prune right away.
Trim the trees in the early spring, winter, or fall. Early summer pruning kills flower buds that could bloom this year. When trimmed in this way, “Annabelle” (H. arborescens) can be used to create attractive hedges by occasionally being cut to only a few inches above the ground each fall or winter. This may lead to a number of issues, one of which is that the enormous flower heads will not be able to be supported by the immature stems (up to 10 across). Avoid this issue by cutting older stems back to 18–24 inches long and letting them become bigger each year.
When blossoms begin to fade in July but before flower buds are set for the following year, prune. Avoid pruning in the early spring, winter, or fall. vulnerable to damage from the cold or frost.
Which hydrangea varieties bloom first?
This hydrangea, appropriately named, has leaves that mimic oak trees as accents. One of the hydrangea species with the earliest blooming times also has stunning fall foliage. This woodland plant is native to North America and has adapted well to the American environment. Oakleaf hydrangeas thrive in full sun to light shade in northern or cooler areas, but in southern or warmer climates, some afternoon sun protection is required. Rich, well-drained soils that are somewhat acidic are excellent for their growth.
Why haven’t the hydrangeas bloomed this year?
Lack of sun and lack of time are the two most typical, fundamental causes of hydrangeas not blooming. Make sure one of these two problems isn’t the cause of your problem before continuing your inquiry.
Although they can thrive in partial sunlight, hydrangeas need at least 4-6 hours of direct sunlight and an additional 4-6 hours of indirect sunlight each day.
Time is the second typical cause of hydrangeas not blooming. Many people demand rapid gratification from their gardens, but that is unattainable. Perennial plants take years to mature, according to Standard. It can take a hydrangea 2–5 years after planting before it blooms, depending on the variety.
If your hydrangea is at least a few years old, receives plenty of sun, and is not flowering, it may be time to investigate further.
What occurs if hydrangeas are not pruned?
If and when you prune is the key to happy, healthy hydrangea flowers. Of course, fertilising 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 colours 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 fertiliser. Come on in, and we’ll show you where to go to develop your green thumb.