One of the most well-liked flowering shrubs for Massachusetts settings is the hydrangea. Indeed, one of the distinguishing features of the Cape Cod garden is the “blue” hydrangea (Hydrangea macrophylla or bigleaf hydrangea). Hydrangeas offer color and beauty throughout the summer and into the fall, whether they are used as a specimen flowering shrub, in a mixed planting with perennials, or in the shrub border.
In our landscapes, hydrangeas of various species are grown. They all generally have comparable cultural expectations. The ideal soil for hydrangeas is one that is continuously moist, well-drained, and rich in organic matter like compost or well-aged manure. They are not particularly resistant of dryness and do not do well in extremely dry, sandy soils. Hydrangeas typically require one inch of water per week, applied in a deep soak. They may need up to 2″ of water every week to avoid wilting in extremely hot and dry weather. In a shrub border of hydrangeas, drip watering or soaker hoses work well since they maintain the soil’s moisture while also keeping the leaves dry, lowering the risk of leaf spots. You may grow hydrangeas in either full sun or dim shade. Particularly the bigleaf hydrangea, which may wilt in full sun even with moist soil, does well if shielded from the intense afternoon heat.
When fertilizing hydrangeas in the early spring and again after blossoming, use a balanced fertilizer weighing about 4 ounces. Hydrangeas prefer a moderate amount of nutrients in the soil. Check the quality of the roots of container-grown plants before planting, and if the roots appear to be circled around the pot or pot bound, loosen them. Add organic material to the planting area and position the plant at the same depth as in the container. The surrounding soil should be level with the top of the root ball. Apply 2 to 3 inches of high-quality mulch over the new plant’s roots, keeping the mulch away from the plant’s crown. Water the new plant thoroughly.
The smooth hydrangea (H. arborescens), which grows as an understory shrub in forests, is a native of the Eastern United States. This species prefers plenty of moisture and partial shade. It develops into a spherical shrub that is 3 to 5 feet high and 3 to 5 feet broad. It blooms in late June or early July, with clusters of 4″ to 6″ wide white flowers. Popular cultivar “Annabelle” produces enormous flower heads that can measure up to 12″ in diameter. The open, lace-cap flower head of the “White Dome” survives well in heavy rain. Pruning should be done in late winter or early spring before new growth starts since smooth hydrangeas bloom on new wood. Zone 4 is the hardiest, however smooth hydrangea may die back to the ground in a very cold winter. As long as it develops flower buds on new wood, it will continue to bloom the next year.
During the month of July, the bigleaf hydrangea (Hydrangea macrophylla) is one of the prominent plants in the landscape. It has an even spread and a height range between 3 and 6 feet, with a rounded habit made up of numerous stiff, unbranched erect stems. Springtime leafing is delayed, and during particularly chilly winters, it can die back to the ground. The Hortensia group of bigleaf hydrangeas features flower clusters made up of several sterile blooms arranged in enormous globes. The Lacecap group is composed of a flat-topped cluster of gorgeous sterile flowers surrounding a center of tiny, fertile flowers.
Bigleaf hydrangea flowers frequently vary in color, with hues ranging from deep pink to red and deep pink to white. Bigleaf hydrangeas need specific pigments in order to turn pink or blue. The blossom will be a shade of blue if there is aluminum in the soil. If there is no aluminum present, the blossom will be pink. Aluminum availability is influenced by soil pH: it is more readily available in low pH soils and less readily available in high pH soils. Flowers will be blue if the soil pH is 5.5 or lower and pink, rose, or red, depending on the cultivar, if the soil pH is 6.5 or higher. The amount of pigment present in a particular cultivar determines the color’s intensity. While “Dooley” will always be either rich blue or rich pink, “Nikko Blue” will always be one of those colors.
Regarding Bigleaf hydrangea pruning, there is a lot of misunderstanding. On mature wood, flower buds often form in the summer and blossom in late June or early July the following year. On the stem’s tip, there is the main flower bud, and there are more buds forming lower down in the leaf axils. These secondary buds do not blossom if the main bud does. Some of these buds might bloom if the main bud is winter-killed. However, freezing weather in the early fall and late spring, as well as winter temperatures below 10 oF, may completely destroy all flower buds, resulting in little to no bloom the next year.
Simply pull out wilted flowers the first several years after planting when they turn brown. Just above the following row of leaves, trim them off. Maintain a healthy structure as the plant ages by cutting the oldest stems (3 years+) all the way to the ground in late winter. At that time, you should also remove any dead stems and tips. If a Bigleaf hydrangea needs to be pruned to control height, do it as soon as the flowers start to fade, right above a set of leaves. Even better, plant it where it will be able to reach its full height and width.
Bigleaf hydrangea breeding advances have led to the creation of cultivars that can bloom on both young and aged wood. This “remontant” quality enables blossoming even when the flower buds are killed by the cold. Among the cultivars with this reblooming ability are “Endless Summer,” “Penny Mac,” and “Dooley.” Up to zone 6, bigleaf hydrangeas are hardy.
The Panicle hydrangea (H. paniculata), sometimes known as the Pee Gee hydrangea, has been utilized in the landscape for many years. With an equivalent spread, this substantial shrub or small tree can grow to a height of between 10 and 20 feet. It blooms from July to September, when huge, 6- to 8-inch-long pyramidal panicles are produced. Fluffy fertile blossoms are dotted throughout the showy, sterile flowers that make up the panicles. The blossoms begin as white but gradually turn a mauve-pink color that lasts throughout the fall. Panicle hydrangeas are the most versatile type of hydrangea. It is the most resilient of the species and is more tolerant of dry spells and direct sunlight. It blooms on fresh wood; if necessary, trim in late winter or early spring to control height. Zone 3 is the hardiest for panicle hydrangeas.
The traditional Pee Gee hydrangea has the cultivar name “Grandiflora,” and it frequently takes on the form of a tree with just one main trunk. Heavy flower clusters, 12 to 18 inches long, allow the branches to arch over, giving the arrangement the appearance of a fountain. Better plants for the garden can be found in more recent varieties that have entered the market. With more fertile than sterile flowers, “Kyushu” is a robust, erect variety that has an open, airy appearance. Lime green flower buds on the 6 to 8-foot-tall and wide ‘Limelight’ plant open to a delicate greenish-white tint. The late flowering cultivar “Tardiva” blooms from late August to October and reaches heights of 8 to 12 feet. A short cultivar, “Little Lamb” only grows to a height of 4 to 6 feet. It also has tiny, delicate flowers, with flower heads that are described to resemble “little lambs dancing around the stem.”
The southeastern region of the United States is home to the native oakleaf hydrangea (H. quercifolia). Its enormous, lobed leaves can grow up to 8″ long and 5′ broad, resembling oak leaves. The 8′-tall oakleaf hydrangea has upright stems that develop in height. By growing stems from the roots, it gradually clumps together, and as it ages, the bark turns shaggy and reddish. Large, white, conical flower heads with both fertile and sterile blooms start to bloom in July. The base of the flower heads can be up to 4″ wide and 12″ long. The blossoms stay beautiful throughout the fall as they mature and dry to a lovely pink-mauve color. The scarlet and burgundy hues of the autumn foliage can be stunning. The flower buds grow on aged wood; if necessary, prune right away after bloom.
The cultivar known as “Snow Queen” has been available for some time and is excellent. It has a more compact growth habit and can withstand the sun well, maturing to a height of 6′. It has creamy white flower heads that are 6 to 8 inches long. One of the more recent varieties, “Alice,” grows to a height of 10 to 12 feet and is particularly strong. Large flower heads up to 12 to 14 inches long with florets the size of a fifty-cent piece are produced by this plant. Multiple bracts on the flowers of “Snowflake” give the impression that they are doubled. The 12 to 15-inch flower heads are so massive that they arch over, giving the impression of weeping. This variety favors moist soil and some shade. With a petite design that only grows to be 3′ tall by 3′ broad, “Pee Wee” is a wonderful choice for smaller gardens. The flower heads are also small, measuring only 5″ in length. Fall colours is good in “Pee Wee.” Zone 5 is the hardiest for oakleaf hydrangeas.
Despite not being a shrub, climbing hydrangea (H. anomela petiolaris) is one of the most magnificent climbing vines that is now accessible. Although it has the same growing conditions as other hydrangeas, it takes longer to mature after planting. Once established, it might climb as high as 60′. The climbing hydrangea ascends by using holdfasts that resemble roots to cling to surfaces. It is frequently positioned next to walls or other structures, especially at the base of large trees. It blooms in June, giving out huge, flat lace-cap-like flowers that can be up to 10″ wide and last for up to two weeks. The horizontal extension of the flowering stems from the surface they are growing on frequently gives the plant a three-dimensional appearance. Golden yellow is a fall hue. This vine is very lovely. Up to zone 4, climbing hydrangea is hardy.
How are hydrangeas pruned in Massachusetts?
One of the most well-liked plants in Massachusetts is the hydrangea, and it is simple to understand why. These plants are not only lovely, but also simple to maintain, durable, and their colors persist longer than those of other typical shrubs.
For the plant’s health and to make room for the upcoming blooming season, hydrangeas must be pruned. In the early spring or late winter, hydrangeas can be clipped.
- Every year, hydrangeas need to have all of their dead stems removed.
- About one-third of the older (live) stems can be cut off at the ground level each summer after the plants have grown for at least five years. The plant will recover as a result.
- If a plant needs to be pruned to get smaller, this can be done in June or July without affecting the bloom the following year. But it will soon shrink back to its original size. This is one of the reasons it’s ideal to plant a hydrangea in an area where it won’t require pruning.
When should hydrangeas be pruned?
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.
Do you prune hydrangeas in the spring or the fall?
Pruning is not typically thought of as one of the many gardening activities that may be done in the fall, despite the fact that there are several. It can be difficult to cultivate hydrangeas successfully in New Hampshire, and if you want your plants to blossom, there is frequently very little room for error in pruning.
Wait until Spring to prune hydrangeas
In New Hampshire, hydrangeas come in a variety of kinds, and each one has quite distinct growth patterns and pruning needs. Some plants only produce flowers on fresh growth, while others mostly produce flower buds on older wood. In any case, it is better to postpone all hydrangea pruning until spring. Hydrangeas, as with all other trees and shrubs, go dormant in the fall. Not much new growth is produced by them until the next spring. As new growth is more vulnerable to harsh cold at the location of wounds, plants that have been trimmed now run a higher risk of winter damage. Additionally, fall pruning may lessen the quantity of June blooms.
Considerations for pruning hydrangea species commonly grown in New Hampshire gardens
The gigantic blue mopheads or lacecaps known as bigleaf hydrangeas (Hydrangea macrophylla), which are familiar to most gardeners, form their flower heads at the tips of stems on old wood from the previous year. Although lower buds along the stem have the capacity to grow blooms as well, the hydrangea’s blossoming potential is decreased if those buds are died or damaged throughout the winter. Wait until new growth sprouts in the spring before pruning your bigleaf hydrangeas. Approximately 1/4 inch above the first group of live buds, prune the plant. A hint: the interior of living stems will be green, whereas the interior of dead stems will be brown. Cut completely dead stems flush with the base.
The three other hydrangea species that are frequently planted in Fresh Hampshire—oakleaf (H. quercifolia), panicle (H. paniculata), and smooth—all bloom on new growth. Before the emergence of the leaves in the late winter and early spring, remove wasted flowers and prune the plant to improve its general structure and habit.
In conclusion, there are a ton of other activities you can engage in to stay occupied in the garden during fall. Save the spring for hydrangea pruning.