Spiraea

( spy - REE - uh )

At-A-Glance Information

This genus of flowering deciduous shrubs, commonly called Spirea, Meadowsweet, or Steeplebush, includes species which need full sun to light shade and moderate to regular water to perform well in the landscape. These shrubs are native to temperate regions of the Northern Hemisphere, with the most species found in eastern Asia. There are two distinct types of Spiraea: those in the 'Bridal Wreath' group produce white flowers in spring and early summer and those in the 'Shrubby' group bloom from summer through fall in a range of colors from shades of pink and red to white. The flowers on these shrubs will attract butterflies to the garden. Use Spiraea as hedges or screening plants, in mixed shrub borders or foundation plantings, or as erosion control on sloped areas. They can also be grown as specimens for their beautiful flowers, and smaller types can thrive in containers on patios.

Spiraea Species and Varietals

The genus Spiraea is in the plant family Rosaceae and includes between 80 and 100 species. The plants in this genus are related to those in Holodiscus (Ocean Spray), Aruncus (Goat's Beard), Aronia (Chokeberry), Chaenomeles (Flowering Quince), Cotoneaster, Malus (Apple), Prunus (Stone Fruit), Pyrus (Pear), Vauquelinia (Rosewood) and Sorbus (Rowan). Previously, the genus included plants in the genera Filipendula and Aruncus, though they have now been separated. Plants in the genera Astilbe and Sorbaria are commonly called 'False Spiraea'; these are plants that look similar and can be used in many of the same ways in the garden. Spirea growing zones vary depending on the species. For more information, review the descriptions below. To find your zone, click here: Zone Map.

Spiraea alba (Meadowsweet, White Meadowsweet, Narrowleaf Meadowsweet, Pale Bridewort, Pipestem)
These plants are native to wet soils of eastern North America, and have naturalized in other parts of the world. They typically reach about 8 feet tall when mature, and produce green foliage and fragrant white flowers with pinkish centers in early summer through fall. White Meadowsweet grows well in USDA hardiness zones 3-8. This species is considered invasive in Belgium and Latvia.

Spiraea cantoniensis (Reeve's Spiraea, Bridalwreath Spirea, Double White May, Cape May, May Bush, Reeve's Meadowsweet, Má Yè Xiù Ixàn Jú, 麻叶绣线菊, Má Yè Xiù Qiú, 麻叶绣球, Kodemari, 小手毬, コデマリ)
This species is native to China and Japan and grows well in USDA hardiness zones 5-9 or Sunset growing zones 3-11 and 14-23, reaching 5 to 6 feet tall and 10 feet wide at maturity. Branches have an arching habit and double flowers bloom in late spring to early summer Leaves are blue-green, and this plant is nearly evergreen in milder climates. The main cultivar of this species is 'Flore Pleno' (pictured; also called Double Bridal Wreath), which produces double white flowers.

Spiraea douglasii (Western Spirea, Hardhack, Douglas' Spirea, Steeplebush, Rose Spirea, Douglas Spiraea, Pink Spiraea)
Best in USDA hardiness zones 4-9 or Sunset growing zones 1-9 and 14-24, native to the Coastal Ranges in Northern California up to British Columbia and east to the Rocky Mountains. It reaches 3-6 feet tall and just as wide. It can be invasive in the garden, spreading via suckers. Leaves are dark green on top and velvety and white underneath. Flowers are pale to deep purple-pink and blossom at branch tips in summertime. This species prefers acidic soil and needs ample water. Great for wild plantings near streams or rivers. This species is considered invasive in Latvia and Denmark.

Spiraea japonica (Japanese Meadowsweet, Japanese Spiraea, Pink-Flower Spiraea, Fěn Huā Xiù Xiàn Jú, 粉花绣线菊, Shimotsuke, シモツケ, 下野)
This species grows well in USDA hardiness zones 3-9 or Sunset growing zones A2, A3, 2-10 and 14-21, and is native to Japan and China. It has an upright, shrubby habit and produces clusters of pink flowers above bright green foliage. This species is considered invasive in the eastern, southeastern and mid-Atlantic United States. Cultivars are more widely grown in gardens than the straight species; they are listed and described below:

'Anthony Waterer'
3-5 feet tall, with carmine-pink flowers and reddish-purple new growth that matures to a vivid green.

'Goldflame'
2.5 feet tall and just as wide, with pink flowers and bronzey new foliage that matures to chartreuse, and turns red-orange in autumn.

'Little Princess'
To 3 feet tall and 6 feet wide, this variety has rose-pink flowers.

'Magic Carpet'
To 1.5-2.5 feet tall and wide with pink flowers and new bronze foliage that matures to chartreuse-yellow.

Spiraea nipponica (Nippon Spiraea, Snowmound Spiraea, Tosashimotsuke,トサシモツケ, 土佐下野, Iwashimotsuke, イワシモツケ, 岩下野 )
This variety grows ell in USDA hardiness zones 3-8 or Sunset growing zones 1-11 and 14-21, and is native to the Honshu and Shikoku Islands of Japan. It is a Bridal Wreath type of Spirea that reaches 2 to 3 feet tall and 3 to 5 feet wide at maturity. Profuse blooms of white flowers are present in late spring through early summertime. Leaves are dark green. Cultivars include 'Snowmound' (to 3-5 ft. tall with a neat mounded habit) and 'Wedding Cake' (compact with dense, fine-textured growth and abundant spring blossoms).

Spiraea prunifolia (Bridal Wreath Spirea, Shoe Button Spirea, Plum-Leaved Meadowsweet, Smiling Dimple Flower, Xiàoyèhuā, 笑靥花, Plum Leaved Spirea, Lǐyè Xiùxiànjú, 李叶绣线菊, Little Clam Flower, Shijimibana, 蜆花, Mancheop-jopamnamu, 만첩조팝나무)
This species grows well in USDA hardiness zones 4-8 or Sunset growing zones A2, A3, 2-11 and 14-21. It is native to China, Japan, Korea and Taiwan and has graceful, arching branches. It reaches 4-9 feet tall and wide at maturity. Flowers are white, blooming in the middle of springtime, and leaves are dark green and turn colors in fall. Cultivar 'Plena' (pictured) has a strong arching growth habit and double white blooms. This species is considered invasive in the eastern and northeastern United States.

Spiraea salicificolia (Bridewort, Willow-Leaved Meadowsweet, Spice Hardhack, Aaron's Beard)
These shrubs are native to east-central Europe, and has been widely introduced to Europe and North America. It has been cultivated since the 1500s, used as hedge plants. It is known to be a bit difficult to control, however, and is no longer widely cultivated. This species is suited for growing in USDA hardiness zones 4-9 and is considered invasive in Europe and North America.

Spiraea splendens (Spiraea densiflora) (Dense-Flowered Spiraea, Rose Meadowsweet, Rosy Spiraea, Subalpine Spiraea, Mountain Spiraea)
These plants are well-adapted to moist, cold, rocky sloped areas near subalpine forests and meadows. They are native to western mountainous regions of North America, from British Colombia down through California. It typically stays under three feet tall, and has light green toothed foliage which turn yellow in cooler temperatures. Fragrant, fuzzy pom-pom flattened flower heads appear in summertime. Leaves have been used historically by Native American populations to make tea. This species grows well in USDA hardiness zones 3-9 or Sunset growing zones 1-9 and 14-21. Leaves are wooly underneath and green on top turning yellow in autumn. Cultivars include 'Summer Song' (to 2.5 ft. tall and wide with bronze new growth and fall color) and 'Trinity Rose' (compact to 2-3 feet tall with blue-green leaves and rose-pink blooms).

Spiraea thunbergii (Thunberg Spiraea, Thunberg's Meadowsweet, Baby's Breath Spiraea, Breath of Spring Spirea, Bridalwreath, Snow-Willow, Yuki-Yanagi, 雪柳, Pearl Spiraea, Zhēnzhū Xiùxiànjú, 珍珠绣线菊)
This species is native to China and Japan, and grows well in USDA hardiness zones 4-8 or Sunset growing zones 1-11 and 14-21. It is a Bridal Wreath species that reaches 3-6 feet or more, and produces round clusters of white flowers along branches in early spring, before leaf-out. Leaves are blue-green and turn reddish to brown in fall. Cultivars include 'Ogon' (also called 'Mellow Yellow' or 'Golden Thread', with yellow-green leaves), 'Mt. Fuji' (to 4-5 feet with green and white leaves), and 'Fujino Pink' (pictured; to 3-5 feet tall with an upright arching habit and soft pink to white flowers).

Spiraea trilobata (Asian Meadowsweet, Threelobe Spiraea, Three-Lobed Spiraea, Sān Liè Xiù Xiàn Jú, 三裂绣线菊, Spireya trekhlopastnaya, Спирея трехлопастная, Tavolga trekhlopastnaya, Таволга трёхлопастная)
This species is native to Siberia and northern areas in China, and grows well in USDA hardiness zones 3-8 or Sunset growing zones 1-11 and 14-17. Foliage is blue-green and three-lobed, hence the specific epithet. It reaches 3 to 5 feet tall at maturity and produces profuse shows of tiny white flowers in springtime. Cultivars include 'Fairy Queen' (compact to 3 feet tall) and 'Swan Lake' (to 3-4 feet tall and slightly wider).

Spiraea vanhouttei (Spiraea x vanhouttei) (Vanhoutte Spiraea, Bridal Wreath Spiraea, Van Houtte's Spiraea)
This artificial garden hybrid grows well in USDA hardiness zones 3-8 or Sunset growing zones A1-A3, 1-11 and 14-21. Branches have an arching habit and leaves are dark green, turning purple-red in autumn. Flowers form in clusters of white from the middle of spring to late spring, and will continue into early summertime if temperatures do not get too high. Cultivars of this species include 'Renaissance' (with good disease resistances), 'Pink Ice' (to 3-4 feet with variegated leaves) and 'Gold Fountain' (with gold-yellow foliage and white flowers).

Caring for spiraea

Spirea are relatively easy to grow, and are not fussy about soil. Plant your Spirea in full sun to partial shade. Most species in this genus do well with at least six hours of sunlight per day; this exposure will ensure optimal growth and flowering. These shrubs, although not too picky about their soil conditions, do prefer soil to be well-draining with a slightly acidic to neutral pH (between 6.0 and 7.0). Water new plants regularly to help establish a strong root system. Once mature, Spirea shrubs are generally drought-tolerant, but do benefit from regular waterings during drier periods of the year. Ensure that soil is draining well; waterlogged roots can cause many issues. Apply a layer of organic mulch around the base of these shrubs after planting to retain soil moisture and regulate soil temperature, as well as to suppress weed growth. Fertilizing is not needed. Prune Bridal Wreath types after flowers have faded, and cut the flowering wood back to the ground. Shrubby Spiraeas should be pruned in late winter or early spring before new growth begins to show. These shrubs generally respond well to pruning after the flowering period has ended. As with many other plants, removal of dead, diseased, damaged, and crossing branches is a good rule of thumb.

Propagation

Spirea can be propagated either by using cuttings or from seed. To ensure that your propagated plant will have the exact same qualities and characteristics as the parent plant, use the cutting method. If you would like to experiment and see what plant you can grow from seed, just keep in mind that it will not necessarily be the same as the parent plant. To propagate your Spiraea shrub, follow the instructions below:

Propagating Spiraea by Cutting

Gather your materials. You'll need a clean, sanitized, sharp pair of garden shears, rooting hormone, a pencil, and a 3-inch pot filled with well-draining compost or other organic material. A good substrate for propagation of cuttings is a light blend of 1/3 pasteurized soil or compost, 1/3 sand, vermiculite or perlite, and 1/3 coconut coir or peat moss.
In spring or early summertime, choose the plant that you'd like to propagate. Ensure that this plant has had a good watering the night before, as this will improve the chances your cutting will take root. Cut one or more 6 inch portion(s) of the end of a non-blooming branch and strip the leaves off of the lower half. Make a hole in your planting medium by pushing your pencil into the soil. Dip the end of the stem in rooting hormone, and plant it in your pot. Fill in soil around the cutting to support it, but do not pack it down too much.
Moisten with water, and ensure that the pot has good drainage. Your pot should be kept in warm, sunny conditions indoors (and not in direct sunlight). Water whenever your soil is dry under the top layer. After about four to six weeks have passed, your cutting should be rooted. When you notice new growth, you'll know you have roots.
Keep your new plant in an area with bright light (though not direct sunlight) and temperatures between 55 and 70 degrees Fahrenheit. Ensure that the soil stays moist, but not wet, until the next spring, when you can transplant it to its new home. Ensure that the last frost of the year has occurred before doing this, as it can seriously damage your new shrub.

Propagating Spiraea by Seed

Keep in mind that the plant you get from seed will not necessarily mimic all of the characteristics of the parent plant. To propagate by seed, you will need a paper bag, a paper towel, a sealable plastic bag, a pot or tray filled with well-draining compost or other organic material, a spray bottle and a fork. The best potting medium for seed germination is a light blend of 1/3 pasteurized soil or compost, 1/3 sand, vermiculite or perlite, and 1/3 coconut coir or peat moss.
Harvest your seeds. The seed pods will dry out, turn brown and begin to open when the seeds are ready to be harvested. Once they have dried out and begun to split open, cut them off the plant and place them in a paper bag. Harvest as many as you can, and place the paper bag in a dry, cool, dark area. They will begin to split open and release the seeds contained inside. Once they have been released, take them out of the bag and put them in a container so you can work with them.
Place the seeds on a damp paper towel, roll the towel up, and place it in a sealable plastic bag. Place the bag in your refrigerator and leave it in there for between 90 and 140 days. Then, move it to an area that stays light and at a temperature of between 65 and 70 degrees Fahrenheit. Seeds should sprout within a few days
Water your prepared seed tray or pot filled with soil, and ensure that good drainage is occurring. Place your seeds in your prepared pot or seed tray about a quarter inch to a half-inch under the soil surface. Cover them with soil and water with your spray bottle. Place your tray of seeds in a warm area that receives bright, indirect light and stays around 70 degrees Fahrenheit.. A greenhouse is the most ideal climate, but a planting tray inside a window will do as well. Germination usually takes a couple of days from sowing.
Once you begin to see seedlings sprout and they are able to be handled, transplant them to their own individual 3-inch pots, filled with the same potting medium as described in Step 1. Loosen the seedlings from the potting medium by digging down with the tines of your fork about an inch and a half, gently working the seedling up until it is out. Then, replant the seedling in its individual pot.
Keep the seedling's potting medium moist, but not wet, by spraying the soil with your spray bottle. Keep your new plant in an area with bright light (though not direct sunlight) and temperatures between 55 and 70 degrees Fahrenheit. Ensure that the soil stays moist, but not wet, until the next spring (after the danger of frost has passed), when you can transplant it to its new home.

Spiraea plants produce small clusters of dry capsules that split open in fall and winter, each releasing a tiny seed.

Spiraea seeds are very small, slender to Banana-shaped, and rusty-brown to tan.

Problems and Pests

Certain Spiraea species are considered invasive in some regions; see the species descriptions above for more information. Check with local authorities before planting. Although Spiraea plants are generally resistant to pests and diseases, they can have some issues with the following common garden pests: