Spirea - A Shrub for All Seasons!
High on the list of toughest Zone 3 shrubs is the incredible Spirea. Incredible because many old and new cultivars are so easy to grow in any Zone 3 garden. The deciduous shrub Spirea has been around for years and varieties such as Goldflame, Gold Mound, Anthony Waterer, Bridal Wreath and Magic Carpet are the backbone of residential and commercial landscapes. In recent years, many new cultivars have come on the market, sporting the same hardiness, bloom power and in addition, outstanding fall color.
There are 80 – 100 species in the Genus Spiraea. Some of these species and their cultivars are sold in garden centres today – Japanese, Bumalda, Birchleaf, Korean, Nippon and Vanhoutte.
Hardy and versatile. Many Spirea varieties are extremely hardy tolerating winter temps of minus 40 degrees C. They can be used as informal flowering hedges, in mass plantings, borders, as foundation plantings and to prevent slope erosion.
They are most useful in mixed borders and as anchors in perennial beds, providing constant color as your flowering perennials transition from season to season. Spireas are particularly striking mixed with evergreens such as blue spruce or cedar.
Spireas do well in full sun and part sun locations (4-5 hours of sun per day). Be aware that if you do plant Spirea in part sun, it will reduce the number of blooms and affect leaf color.
Spireas come in all sizes, are low maintenance, drought tolerant once established and will even stand up to road salt. They are not fussy as to soil type as long as it has good drainage and is not kept constantly wet.
Many are known for their colorful new growth, summer and fall bright foliage.
Spireas in Zone 3 are known for their longevity of bloom with a few blooming in fall as well. Their flowers and foliage make great cut flowers for indoor arrangements (spring or fall). Depending on the species, the tiny flowers are clustered together in panicles, corymbs or drooping clusters. They come in shades of pink, mauve, red, or white. Pollinators love the flowers (especially butterflies) and when these shrubs have gone to seed, become a good winter food source for birds.
One variety on the market, called Spiraea x Double Play Doozie is a seedless cultivar and constantly blooms a dark red -pink from early summer to the first hard frost. No deadheading required! Certainly a lot of bang for your buck!
Spring and early summer (June) are the best times to plant spirea. Check the growers tag for mature height and width and allow for the mature size in your chosen space. I have grown many spirea and I can assure you, they will reach their mature size!
You can plant in early fall, but do use a root booster at the time of planting. Mulch around the base of the shrub with compost or leaf mold. To avoid stem rot, do not pull the mulch up too close to the base of the shrub. Make one more application of root booster in early spring of the following year.
Watering and Fertilization – Spirea do need regular watering the first year after planting to establish a strong root system. In subsequent years, apply half strength water soluble 20-20-20 or a slow release granular tree and shrub fertilizer just once yearly in early spring as the shrubs leaf out.
Spirea require very little pruning, if at all. The five cultivars I have listed below all bloom on new wood (current years growth) so can be pruned in late winter or early spring just before leaf bud break. Some species are early spring bloomers so should not be pruned in spring until after they flower. Do check the pruning requirements of your particular Spireas, as they can vary. Every three years you can cut them back to 15 – 20 cm to rejuvenate the entire shrub. Spirea can also be deadheaded to encourage new blooms. Just lightly shear after blooming.
Bonus: While no plant is totally safe from deer and rabbit browsing, Spirea are deer and rabbit resistant. Insect and disease problems are rare.
Fritschiana Spirea (A Korean Spirea – native to China and Korea)
Spiraea fritschiana ‘J.N. Select’ (Johnson’s Nursery)
Zone 3-8 Full Sun 61-91 cm x 91 cm – 1.21 m
This is a white, summer flowering Spirea that has exceptionally striking fall leaf color; glowing yellow, orange and red. This shrub has a natural rounded form.
Prune as described above but do not take off any more than 1/3 the volume of the shrub.
Fritsch produces giant clusters of white summer blooms. Deadhead spent blooms to encourage another flush of flowers.
This species is also available in a pink flowering selection called Pink-A-Licious Fritsch Spirea (Spiraea fritschiana ‘ J.N. Select A ’ )
Pink Sparkler Birchleaf Spirea (First Editions)
Spiraea betulifolia ‘Courispio1’ Zone 3-8 Full Sun to Part Sun
91 cm – 1.2 m x 91 cm – 1.2 m
The foliage is bright green, in a mounded, upright form.
Pink clusters of blooms on all branch ends in early summer. Dead-head spent blooms. Re-blooms in the fall with abundant flowers going up and down each stem. Minimal pruning required unless rejuvenating a tired old shrub in early spring.
Pink Sparkler also makes a striking visual statement in fall with burgundy-red leaves.
Double Play ‘Blue Kazoo’ (Proven Winners)
Spiraea media ‘SMSMBK’
Zone 3-8 61-91 cm x 61-91 cm Sun to Part Sun
This Spirea has unique bluish/green foliage in spring that turns a beautiful burgundy red in fall. Spring foliage takes on subtle shades of red, purple, green and pink as it matures.
Blue Kazoo has a natural mounding growth habit.
This Spirea is very easy care, blooming on new wood. Large white flower clusters appear in early summer and fall. Deadhead as flowers fade.
Blue Kazoo grows well in lightly shaded conditions (4 hours of sun per day) but does best in a full sun location.
Poprocks Petite Spirea (Bloomin Easy)
Spiraea japonica ‘Odessa’ Zone 3 – 9 Full Sun
60-90 cm x 60-90 cm
If you like bold, bright colors, you will love Pop Rocks Petite Spirea! Little and mighty, this is probably the hardiest Spirea of the new introductions, tolerating minus 40 degree C winters. Lightly prune to shape in early spring before it leafs out.
Pop Rocks has an almost perfect compact rounded form. It is a heavy bloomer with clusters of bright pink button flowers that sit above the deep green foliage. Use Pop Rocks Petite along walkways, in borders, mixed beds, perennial gardens, mass - plantings or as low hedges. Bees, butterflies and hummingbirds love the blooms, making this shrub a must in any pollinator garden.
Once established after planting it is drought and salt tolerant.
Deer and disease resistant.
Pop Rocks will continue to bloom all summer!
Fall leaf color is a beautiful orange – red.
Superstar Spirea (First Editions)
Zone 3 - 8 Full sun.
Spiraea x bumalda ‘Denistar’
61-91 cm x 91 cm – 1.21 m
Superstar Spirea has bright new growth which is a gorgeous scarlet red that slowly transitions to green as the summer passes. It has a natural rounded form.
Clusters of apple-pink blossoms appear in June on new growth and if deadheaded will re-bloom in August. Butterflies love these flowers and the blooms do attract other pollinators as well.
Superstar is drought tolerant once established and deer/rabbit resistant.
In fall the foliage transitions to a beautiful copper color.
Use Superstar in mass plantings, as natural hedging, in perennial borders and mixed beds.
Just to let you know, this blog is for informational purposes only. It does not reflect current availability at Floral Acres. Inventory varies daily, weekly and seasonally.