When to prune spireas?

Tracy Hebden

When and how do I trim overgrown, poorly flowering, 20-year-old Vanhoutte spirea bushes?

Frances Sperl, Denver, CO

Dear Frances,
Vanhoutte spirea (Spiraea x vanhouttei) is a popular hybrid of two less well-known species, S. cantoniensis x S. trilobata. It blooms in late spring to early summer, with dense, flattish clusters of clean white flowers, borne on arching stems. To renovate 20-year-old bushes, you may need to take some drastic action (trimming will not be sufficient) that will result in a couple more years of poor bloom before you see results. After flowering time, take a careful inspection of the bushes and determine how many young stems have developed at the base. These types of spireas bloom on new stems that grow from older ones, so if there is strong young basal growth, you will want to encourage it. Cut out about a third of the old, thick wood to the base (you may need a pruning saw for this job, or loppers may be strong enough). This will open up the shrubs a lot and make it easier to see what else needs to be removed. Any dead, diseased or crossing branches should come out as well. If some of the remaining stems are too long, trim them back by about a fourth to a third their length. To try to keep the center of a bush open, it is important to cut to an outward-facing bud.

If your specimens are really overgrown, you might just want to cut the whole thing down to about a foot tall and wait a couple of years for new stems to grow. After such drastic pruning, be sure to keep the plants well watered and feed with a complete fertilizer several times during the season.

Anthony Waterer Spirea in bloom

Anthony Waterer Spirea in bloom

(Photo courtesy of NetPS Plant Finder)

Anthony Waterer Spirea flowers

Anthony Waterer Spirea flowers

(Photo courtesy of NetPS Plant Finder)

Height: 29 inches

Spread: 3 feet

Sunlight:

Hardiness Zone: 3a

Other Names: Spiraea japonica

Description:

A broadly spreading garden shrub featuring attractive clusters of carmine-red flowers offset against the foliage, turns purple in fall; very low maintenance plant, excellent in groupings, needs full sun and well-drained soil

Ornamental Features

Anthony Waterer Spirea features showy clusters of rose flowers at the ends of the branches from late spring to early summer. It has attractive bluish-green foliage which emerges brick red in spring. The small serrated pointy leaves are highly ornamental and turn an outstanding burgundy in the fall. The fruit is not ornamentally significant.

Landscape Attributes

Anthony Waterer Spirea is a multi-stemmed deciduous shrub with a more or less rounded form. Its relatively fine texture sets it apart from other landscape plants with less refined foliage.

This shrub will require occasional maintenance and upkeep, and is best pruned in late winter once the threat of extreme cold has passed. It is a good choice for attracting butterflies to your yard, but is not particularly attractive to deer who tend to leave it alone in favor of tastier treats. It has no significant negative characteristics.

Anthony Waterer Spirea is recommended for the following landscape applications;

  • Mass Planting
  • General Garden Use

Planting & Growing

Anthony Waterer Spirea will grow to be about 29 inches tall at maturity, with a spread of 3 feet. It tends to fill out right to the ground and therefore doesn’t necessarily require facer plants in front. It grows at a fast rate, and under ideal conditions can be expected to live for approximately 20 years.

This shrub should only be grown in full sunlight. It prefers to grow in average to moist conditions, and shouldn’t be allowed to dry out. It is not particular as to soil type or pH. It is highly tolerant of urban pollution and will even thrive in inner city environments. This particular variety is an interspecific hybrid.

Caring for Your Spireas over Winter

Shrubs like spireas are perfect for creating mixed border patterns or compact hedges in your garden. Spirea is considered one of the easiest-to-grow shrubs with dense, weather-resistant foliage patterns and colorful seasonal blooms. The shade of spirea flowers ranges from pink to bright, white hues. Spireas are hardy plants that need minimal care but a few precautions should be taken during the winter season. Winter care is recommended because spireas are essentially summer-blooming shrubs that have adapted to colder conditions.

Winter Watering Care

Spireas need minimal water and don’t require periodic watering like common garden plants. However, during the late fall season or just as the winters are about to set-in, ensure that you water the spirea soil bed intensively. This is suggested because during winters, the ground water freezes. Therefore, heavy doses of watering before the winters ensure that the moisture of the soil bed is preserved. Using winter mulch is recommended as it helps to keep the shrub moisturized and prevents the lower stem being weakened due to freezing and thawing.

Winter Pruning Care

Most spirea varieties react well to being pruned during the late winter season. The removal of weathered flowers, i.e. deadheading, during winters ensures new growth during the spring season. This also encourages repeated blooming in the spirea shrub.

Winter Rooting Care

Some spireas tend to develop young roots that emerge out of the soil bed. During the winters, roots growing over the ground are easily destroyed due to freezing temperatures. You should dig under the roots and push them back, inside the soil.

Pruning Spirea Shrubs: Learn About Trimming Spirea Plants

Spirea is a lovely foundation plant, providing greenery and flowers. But, it’s a common complaint that these small shrubs start to look ugly after a season or two. The solution is simple: trimming spirea plants keeps it looking healthy and attractive year after year.

Importance of Pruning Spirea

There are several reasons to trim your spirea regularly, at least twice a year. The first is to keep it healthy. A good trim helps get rid of dead branches and leaves and allows more sunlight in to the new growth that is struggling at the bottom or interior of the shrub. Trimming also gets more airflow between branches, which deters fungal infections and is a good way to restore health and vigor to an overgrown, neglected shrub.

The other main reason to do regular spirea pruning is to keep your shrubs looking attractive. Without trimming, these shrubs tend to look woody, with dead branches, and overgrown. The stems can start to look tangled and messy.

How to Prune Spirea

You should actually prune your spirea more than once a year, at least twice. Give it a good trim after it flowers in the spring by cutting back the tips of the stems to the top leaf bud. This removes the dead blossoms and also may trigger a second blooming and new leaf growth. You can also shape the shrub at this time.

More drastically cutting back spirea should occur in the fall or in late winter to early spring. Remove any dead branches and use this trimming to shape the shrub. Cutting it way back will stimulate new growth in tighter clusters so that you can get a more rounded, compact shrub shape.

A professional strategy for getting perfectly rounded spirea is easy enough for the home gardener. Tie a piece of rope around the center of the shrub. Trim straight across the top of the plant, and when you release the rope you’ll have a perfectly rounded spirea.

The two main trimming periods, in early spring and after blooming, are most important to do each year, but you can also trim your spirea as needed throughout any season. This is a shrub that responds well to trimming, so prune and shape as needed.

How to grow Spiraea

A beautiful late spring /early summer flowering shrub, Spiraea is very hardy and suitable to grow in most locations, although for the showiest flowers Spiraea is best grown in full sun. Spiraea is easy to grow, self sufficient and has no particular growing or pruning requirements unless the shrub is getting too large, or tangled, when you can opt to do so a light trim after flowering. Spiraea is a genuinely a low maintenance easy to grow shrub which really needs no attention once planted.

Once established Spiraea is easy to grow and all that is required is trimming or pruning if it gets too large after flowering in summer. If the shrub does need pruning, take out the old shoots from the base and trim back the younger stems to required size. If you do decide to prune Spiraea, it is best to prune after flowering in late summer

Spiraea is deciduous and it looks very different in the winter compared to summer, as shown in the image below. Spiraea canescens left in early summer, right in winter. It looks dead in the winter, so if you come across it in the garden, don’t be tempted to dig it up, come the spring it will reward you. Spiraea are fully hardy H6 which is to -10 down to -20.

Neon Flash Spirea

Neon Flash Spirea is a deciduous flowering shrub. This plant exhibits dark green foliage with bright pink flower clusters. New foliage is lime-green which turns dark when mature. The leaves of this spirea are long, narrow, and have serrated edges. The dark green foliage turns dark red in the fall when cooler temperatures return. This spirea variety can be planted as a stand-alone plant or in a hedge.

Neon Flash Spirea blooms all summer long. The flower clusters are made up of many tiny bright-pink flowers assembled. Flowers are not much larger than the size of a pencil eraser. This plant is a fast-growing, yet small spirea shrub. The branching of this spirea tends to be more upright than random.

When the plant is fully mature, it can reach up to three feet tall and wide. This spirea needs regular watering during periods of extreme heat and drought conditions. Neon Flash Spirea is a great plant to use to attract butterflies to your property.

Spiraea Japonica ‘Neon Flash’

Flower Color- Neon Pink

Foliage Color- Dark green

Zone- 4-8

Height- 3′

Spread- 3′

Light-Part shade to full sun.

Details- Bright red to pink flowers cover this shrub from late spring to fall. This plant is a fast-growing shrub.

Pruning- Pruning should be done immediately after the plant is done flowering in the fall. Pruning can be done at other times of the year, but you risk reducing future flowers. As a stand-alone plant, Neon Flash Spirea should be pruned as a globe. When planted in rows, this plant can be shaped as a hedge.

Other Spirea plant options.

  • Anthony Waterer Spirea
  • Birchleaf Spirea
  • Daphne Spirea
  • Dolchica Spirea
  • Fire Light Spirea
  • Gold Flame Spirea
  • Gold Mound Spirea
  • Little Princess Spirea
  • Magic Carpet Spirea
  • Renaissance Spirea
  • Shirobana Spirea
  • Snowmound Spirea
  • Tor Birchleaf Spirea

Japanese spirea

Size & Form

Spirea comes in variable sizes , depending upon cultivar
Typically 2 to 3 feet high and 3 to 5 feet wide, but some cultivars can go up to 5 to 6 feet high and wide.
Falls into two categories, spring-blooming and summer-blooming with white or carmine-pink flowers

Tree & Plant Care

Compact, mounded shrubs
Requires well drained soil, intolerant of wet sites.
Best in full sun, but many will grow in light shade.
All spirea benefit with a periodic pruning to to keep plants in shape and initiate new growth.
Can be cut to the ground and will grow back from the roots.
Flowers on new wood, prune in early spring; pruning after flowering often will promote a second sporadic flush of flowers.
Tolerant of aerial salt spray

Disease, pests, and problems

Wet soils promote root rots, powdery mildew, leaf spots

Native geographic location and habitat

Japan, Korea, China

Attracts birds, pollinators, or wildlife

Butterflies are attracted to the summer flowers

Bark color and texture

Multiple, brown, thin and twiggy stems

Leaf or needle arrangement, size, shape, and texture

Alternate, simple leaf, 1 to 3 inches long and 1 to 2 inches wide, serrated or toothed leaf margins.
Depending upon cultivar, new leaves emerge reddish-orange or with a pink tinge, changing to medium green for summer and back to a orange-red fall color.

Flower arrangement, shape, and size

Flowers on new wood. Most are summer blooming, but a few cultivars bloom in spring.
Flowers are 3 to 4 inch, flat clusters (corymbs) of white to deep pink in June through August.

Fruit, cone, nut, and seed descriptions

A dry, brown follicles, persistent through winter, not ornamentally significant.

Cultivars and their differences

Note: This plant is often confused with Spiraea x bumalda, so refer to the cultivar listings for this species if you are unable to locate in a nursery.

Alpine Japanese spirea (Spiraea japonica ‘Alpina’): A low-growing, spreading ground cover shrub, about 2 feet high and 4 to 6 feet wide. It produces light pink blooms and contrasts well with the small, blue-green, finely-textured leaves.

Anthony Waterer Japanese spirea (Spiraea japonica ‘Anthony Waterer’) (syn. Spiraea x bumalda ‘Anthony Waterer’): A 4 feet high, upright, mound of dense stems that grows 5 feet wide or more. The summer blooms are 4 inches wide, flat-topped clusters and a deep red-pink. The blue-green leaves turn reddish in fall.

Curled-leaved Japanese spirea (Spiraea japonica ‘Crispa’): A 3 to 4 feet tall and wide form of ‘Anthony Waterer’ with unique finely-textured leaves that are twisted and dissected. Flowers are a lighter pink.

Double Play™ Artisan® Japanese spirea (Spiraea japonica ‘Galen’): A 2 1/2 feet tall compact habit. Purple-red spring foliage turns a blue-green in summer, flowers are a rich pink.

Double Play™ Gold Japanese spirea (Spiraea japonica ‘Yan’): Vibrant gold foliage, pink flowers, low-mounded, compact habit reaching 16 to 24 inches high.

Golden Princess® Japanese spirea (Spiraea japonica ‘Lisp’): A 2 feet high mound with bright yellow leaves that start out bronzy-orange. The 3 inch wide bright pink flowers appear in early summer.

Golden Thumbellina™ Japanese spirea (Spiraea japonica ‘KLMthirteen’): Mounded 2 feet high and 2 to 3 feet wide; pink flowers accented against yellow foliage

Goldflame Japanese spirea (Spiraea japonica ‘Goldflame’): A yellow-leaved cultivar reaching 2 to 3 feet high and wide. New leaves emerge bright orange-red in spring and gradually fade to yellow. Flowers are a light pink.

Goldmound Japanese spirea (Spiraea japonica ‘Goldmound’): A low, 2 to 3 feet high, mounded, golden yellow form that does not fade in the summer sun, drought and heat. The early summer lavender-pink flowers add nice contrast.

Little Princess Japanese spirea (Spiraea japonica ‘Little Princess’): A fine textured, green-leaved form with bright pink flowers on a 2 to 3 feet high and wide mound. Flowers are pink fading to white.

Magic Carpet Japanese spirea (Spiraea japonica ‘Magic Carpet’): A vibrantly colored, low mounded, 18 to 24 inches high and wide with bronzy-yellow leaves. New leaves emerge a vibrant orange-red and retains red-tipped branches all season. Flowers are pink. Fall color is a russet red that persists late into season.

Neon Flash Japanese Spirea (Spiraea japonica ‘Neon Flash’): A 3 feet high, mounded shrub with rich red flower clusters, reddish new growth turns dark green.

How to Deadhead Spirea Bushes

Spirea is a flowering shrub with long, vertical stems that emerge from a central location in the ground. In the spring and summer, the stems are covered in clusters of white or brightly colored tiny flowers. In southern climates, the blooms often last until the first frost. Achieving these repeated blooms requires deadheading (removing old blooms) throughout the season.

Wait until the spirea bush begins blooming in the spring, and then examine the plant regularly to identify wilted and dying blooms. The new spirea blooms typically last for one to two weeks before they show signs of fading.

Grasp one of the dead blooms and locate the first set of leaves underneath, on the stem. In some varieties, the leaves are located just under the flower, but in others they can be 3 to 4 inches down the stem. Cut the dead flower off using hand pruners, and make the cut straight across the stem, just above the leaf set.

Repeat the process to deadhead the spirea plant through the remainder of the growing season.

Wait until the end of the summer or fall when all the spirea stems stop blooming. Deadhead all remaining stems by cutting off the last 1 to 2 inches, using pruning shears to speed the process along. Rake up the spirea trimmings and dispose them.

Mid-Summer Deadheading…and Other July Garden Touchups

Many people expect to be able to stop all work in their yards and gardens in July and August…with the exception of lawn mowing, of course. But there are some plants that will perform better, and look more attractive, if you spend some time doing a bit of cleanup in early July. There are also other garden tasks that will improve your yards performance.

Deadheading: This is merely the practice of clipping off old flowers to stimulate the growth of new foliage and blossoms. Roses can be deadheaded now, and you don’t have to clip anywhere special…just cut off the dried flowers or seed pods. The myth about cutting above a set of 5 leaflets is just that: a myth. Pink flowering spirea should also be deadheaded. You can cut off old flowers using a pruners, hedge shears or an electric shearing tool. In the perennial garden deadhead any plant that flowered before June 30th including: salvia, baptisia, nepeta, peonies, coral bells, oxeye daisies, bleeding heart and penstemon. As an alternative to deadheading, salvia, nepeta and penstemon can be cut to the ground.

Planting: Adding annuals in July is desirable because they will provide three to four months of color. This is especially welcome if many of your perennials flower in spring or early summer, or if you have large areas of brown bark mulch in between other plants. Tip for success: mix some time-release fertilizer into the area where your annuals will be planted so they will be automatically fed for the rest of the summer.

Watering: Deeply less often is best for all plants. Do NOT rely on an irrigation system that only comes on for 15 minutes at a time…that kind of watering merely dampens the first couple of inches of mulch and soil. Do NOT hand water in your veggie garden…use a soaker hose or sprinkler so that the soil gets moistened deeply. A deep soaking promotes the growth of deep root systems, and this makes for stronger, healthier plants.

Fertilizing: If you think your plants need a mid-summer feed, by all means apply the fertilizer of your choice. If you pick a synthetic fertilizer be sure the plants are well watered and hydrated before application. An organic fertilizer applied now will be available to the plants in mid-August.

Cutting three to six inches off the stems of pink-flowering spireas will improve the appearance of the shrubs and promote new growth. If your spireas didn’t get cut back in the spring you can take as much as six to eight inches off now. When deadheaded in early July the plants will flower again.

Early July is the time to deadhead roses. Even the shrub roses that are good about repeat flowering (Knockout, Drift, Oso Easy, Flower Carpet, Home run, and The Fairy, for example) will produce a second round of flowers earlier when deadheaded.

Spirea not just spring bloomers

A queen of the summer landscape border … the family of Spirea.

For years if you spoke the name Spirea, the vision folks saw dancing in their heads was that of the gracefully weeping white Bridal Veil or Vanhoutte Spirea, which bloom in the spring. Today, that’s all changed; say Spirea and the question that immediately follows is, “Which one?”

Chances are you may already be the proud caretaker of one of these beauties — if not, your neighbor has one or you’ve walked past one going into a store. They’ve become that common.

Very easy to grow, all spireas ask for is a sunny spot where the soil is well drained. They aren’t particularly fond of wet feet and, once acclimated to the location, they will survive dry conditions quite nicely. That’s why you often find them planted in median strips and island beds surrounded by asphalt in mall parking lots.

They are beginning to bloom and will continue to do so throughout the summer. Although they bloom prior to July 4, you can prune this group of Spirea in late winter to help force new growth where this year’s flower buds will form (do not prune spring blooming Spirea until immediately after they flower).

Unlike their cousin the Bridal Veil, who tends to grow very large — well over 6-feet high and wide — this later-blooming group of Spirea is a tad more reserved in its growth depending on the genus and cultivar. They can range in height as low as 18 inches or as tall as 48 inches.

For a shrub, they are considered long blooming, and their flowers easily tolerate the heat so their bloom time isn’t rushed as a result of a heatwave. You can plan on them blooming a good five weeks or so. Once their first flush is done, shear them back to dead-head the spent flowers and you will end up exposing a second flush of buds that have formed down the stem.

Great for indoor bouquets, they have a good vase life and dry very nicely, especially the darker shades. Use them in everlasting bouquets or wrap them into a wreath while the flower is still fresh and pliable, then allow it to dry. They make gorgeous wreaths.

Japanese Spirea, also known as Spirea japonica offers pink shaded flowers. Ranging in height from around 24 inches to 48 inches with a comparable width, it offers a variety of foliage options from dark green to lime green, yellow to a golden bronze with some even hedging toward a red hue. Little Princess, Goldmound and Shirobana are varieties to look for, each offering its own specialty whether it be height, flower color or leaf color.

The Bumald Spirea or Spirea x bumalda is widely utilized. Here’s where you’ll find that spectacular dark carmine flower belonging to Anthony Waterer that will be in bloom throughout July.

The variety Goldflame is aptly named with its pink flaming flowers atop its yellow foliage. It sounds like a harsh combination but massed together in an island bed on a large lawn, it’s stunning and come fall watch for a brilliant “orange-red” flame colored foliage. For leaf texture, Crispa has to take top awards with its very serrated leaf margin and flowers similar to Anthony Waterer.

Come fall, each variety offers a great foliage show. Once the leaves have fallen, the stems provide their own interest for the winter months with tiny bumps running up and down. When dusted with snow, the bumps seem even more pronounced.

Years ago a friend gave me a number of small pots of Goldflame Spirea, which I planted down in my little nursery. Today, they have generously re-seeded themselves quite nicely forming a beautiful flowering ground cover. If you have a sunny hillside or area that mowing or caring for is too time consuming, consider planting a few Goldflames and let the flowers dry on the branches so the seeds mature fully and fall off. Allow them to “grow where they sow” or dig them up and transplant. It’s a colorful ground cover technique that takes little gardener-power.

All of today’s Spireas are hardy zones 4 to 8 and appreciate a pH of 6.5 to 6.8. Remember, you can bend the pruning rule with these guys if you prune them in late winter well before they begin to break dormancy. If you miss the window, just leave them, enjoy them and prune after they bloom to shape them.

One last note: Mixing shrubs into the perennials border can be a daunting chore; these Spireas blend as if they grew for only that reason.

Multi-tasking, year-round great shrub that requires very little maintenance — what more can we ask for?

Nancy O’Donnell owns Perennial Graphics Nursery in Schaghticoke. Contact her by e-mail at [email protected] Gardener’s Notebook can be found online at http://timesunion.com/life.

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