Astilbe
Soft, Spiky Flowers for Shade
Astilbes are deer-resistant, shade-loving perennials with pretty flowers and graceful, fern-like leaves.
Astilbes are a genus of clump-forming, herbaceous perennials that are native to Asia and eastern North America. With easy-care flowers for the shade, astilbes are very popular garden plants. Attractive foliage and soft, spiky flowers in shades of white, pink, red, lavender, and purple bring colorful drama to the shaded areas of the front yard or backyard. Astilbes are widely available at nurseries, garden centers, and even some big box retailers.
There are many different varieties of astilbes on the market, varying in flower color, bloom time, and height (read on for a list of the best astilbe varieties). In general, astilbes typically grow between 1-4 feet high, and have dark green, finely cut, fern-like leaves that are attractive on their own. In early to late summer, the plants produce tall upright stems that are topped with fluffy plumes of flowers on strong stems. As the flowers mature and fade, the seed heads dry on the plant, adding visual interest to the winter garden while serving as a food source for numerous bird species.
Astilbes grow in zones 3-8, and prefer moist, well-draining soil and partial to full shade. When plants are not receiving enough water, the foliage will become brown, dry and crispy. They are a relatively low-maintenance plant, avoided by deer and rabbits, and do not have many insect or disease problems. Rutgers University rates astilbes as “seldom severely damaged by deer” on their list of Landscape Plants Rated by Deer Resistance. Give astilbes an annual feeding of compost in the spring time, and divide every 3-4 years to maintain plant health and avoid overcrowding.
Image credit: Yoksel Zok
How to Plant and Grow Astilbe
Location: Astilbes thrive in partial to full shade, making them an excellent choice for shaded or woodland gardens. Ensure the soil is rich, moist, loose and well-draining. Astilbes prefer slightly acidic soil.
Planting: Plant astilbe in the spring or fall, and space 18 to 24 inches apart on center (18-24 inches from the center of one plant to the center of the next plant). Try this handy plant calculator to determine the number of plants required for your garden.
Watering: Keep the soil consistently moist, especially during the first growing season. Astilbes prefer consistently damp conditions (for watering guidance, see “How to Water your Plants”). Water deeply and regularly, especially during dry spells.
Mulching: Apply a layer of mulch around the plants to help retain soil moisture and suppress weeds. This is particularly important for moisture-loving astilbes.
Fertilizing: Create the organically rich, moisture retentive soil astilbes love by amending the soil with compost or garden manure. Adding a slow-release, organic fertilizer (such as Holly-tone) will increase the flowering display and help to create the acidic soil astilbes prefer.
Division: Astilbes can be divided every 3-4 years to maintain plant health and vigor. Divide in early spring before new growth begins or in the fall. Lift the entire clump, divide it into smaller sections, and replant.
Astilbe x arendsii vs. Astilbe chinensis vs. Astilbe japonica
Astilbe chinensis, Astilbe × arendsii, and Astilbe japonica are different species within the Astilbe genus, and they tend to have some differences in terms of characteristics and growing conditions:
Astilbe chinensis is native to China and Japan, and known for its tolerance of drier conditions when compared to other astilbe species. It can tolerate partial sun, the flowers tend to be more open and airy, and the foliage a deeper green.
Astilbe × arendsii are a hybrid species developed by the German nurseryman George Arends. They are derived from crossbreeding Astilbe chinensis, Astilbe astilboides, Astilbe japonica, and Astilbe thunbergii. These hybrids do not tolerate drought well and require partial to full shade. Flower plumes are dense and tight, and the foliage ranges from light to dark green.
Astilbe japonica are native to the mountains of Japan, and grow best in cooler, moist soil and partial to full shade. Most are early to midsummer bloomers, and have tight, pyramid-shaped flowers.
New and Popular Astilbe Cultivars
White Flowers:
Astilbe ‘Deutschland’
‘Bridal Veil’ (Astilbe x arendsii ‘Bridal Veil’). A classic, elegant choice. Young bronze foliage turns green, flowers are a lacy pure white. Grows to 28 inches tall and flowers from June until early August.
‘Deutschland’ (Astilbe japonica ‘Deutschland’). A short, compact plant with luminous white flowers and glossy green foliage. Blooms from early to midsummer and grows 18-24 inches tall.
‘Easy Listening’ (Astilbe Music™ ‘Easy Listening’). Pale white flowers atop dark green stems and leaves. Blooms in July & August; grows 18-30 inches tall. Part of the astilbe “Music Series”, a new improved group of heavily-flowering astilbes.
‘Rock and Roll’ (Astilbe Music™ ‘Rock and Roll’). Dark bronze-green foliage and pure white blooms. Part of the astilbe “Music Series”.
‘Snow Drift’ (Astilbe x arendsii ‘Snow Drift’). Pure white flowers top airy green foliage. Grows 18-20 inches high and blooms from early to mid-summer.
Pink Flowers:
The soft, spiky flowers of Rheinland astilbe (Astilbe x arendsii ‘Rheinland’)
‘Bressingham Beauty’ (Astilbe x arendsii ‘Bressingham Beauty’). Dense rose-pink midsummer blooms on a taller plant, growing up to 3 feet high.
‘Honky Tonk’ (Astilbe Music™ ‘Honky Tonk’). Midsummer rose-pink blooms top dark green, compact foliage. Grows up to 24 inches tall. Part of the heavily-flowering “Music Series”.
‘Mighty™ Pip’ (Astilbe chinensis ‘Mighty™ Pip’). 4-foot tall plumes of salmon pink flowers bloom in early to midsummer. Great for a naturalistic landscape or woodland garden.
'Peach Blossom’ (Astilbe x rosea ‘Peach Blossom’). Early summer bloomer growing 18-24 inches high. Airy, peach colored flowers with a touch of pink. Looks great when planted in mass.
‘Rheinland’ (Astilbe x arendsii ‘Rheinland’). Late spring to early summer rose-pink blooms. Glossy green leaves can be tinged with red; grows to 24 inches tall.
‘Satin Pearls’ (Astilbe chinensis ‘Satin Pearls’®). Bubblegum pink flowers and dark green foliage. Late spring to early summer bloom time; grows 20-28 inches tall and 16-24 inches wide.
‘Sprite’ (Astilbe ‘Sprite’). A dwarf variety for the front of the border or as a ground cover. 10-18 inches tall, pale pink flowers from late spring to early summer.
‘Visions in Pink’ (Astilbe chinensis ‘Visions in Pink’). Rose pink flowers in midsummer, growing 12-20 inches tall. ‘Little Vision in Pink’ has the same characteristics in a smaller size - grows to 14 inches tall, making it great for the front of the border.
Younique™ ‘Silvery Pink’ (Astilbe Younique™ ‘Silvery Pink’). A short, compact plant blooming in early to mid summer. Pale pink flowers top light green leaves, grows to 22 inches tall. Great for containers or the front of the border.
Red Flowers:
‘Hot Pearls’ (Astilbe chinensis ‘Hot Pearls’®). Late summer red blooms atop medium green foliage, grows 18-20 inches tall.
‘Fanal’ (Astilbe x arendsii ‘Fanal’). A classic astilbe with garnet red flowers rising above bronzy green foliage. Mid-spring to summer blooms reaching 1-2 feet tall.
‘Lowlands Ruby Red’ (Astilbe chinensis ‘Lowlands Ruby Red’). Cherry-red flowers and glossy green foliage. Blooms in summer; reaches 20-24 inches in height.
Mighty™ Red Quin (Astilbe chinensis ‘Mighty™ Red Quin’). 4-foot tall plumes of red flowers bloom atop green foliage in early to midsummer. Great for a naturalistic landscape or woodland garden.
‘Montgomery’ (Astilbe japonica ‘Montgomery’). Raspberry red flowers on crimson stems, with bronze foliage changing to green as the season progresses. Blooms in June and July; grows to 24 inches tall.
Lavender and Purple Flowers:
‘Amethyst’ (Astilbe x arendsii ‘Amethyst’). Lavender flowers top lacy green to bronze-green foliage. Blooms from early to midsummer, grows 24-36 inches tall.
‘Black Pearls’ (Astilbe chinensis ‘Black Pearls’). Brilliant purple flowers bloom in mid- to late summer over dark green leaves. Grows 12-36 inches tall.
‘Little Vision in Purple’ (Astilbe chinensis ‘Little Vision in Purple’). A compact habit and fine, lacy bronze-green foliage. Dwarf, compact size growing to 12 inches tall. Raspberry-purple late spring flowers.
‘Purple Candles’ (Astilbe chinensis ‘Purpurkerze’ Purple Candles). Midsummer flowers emerge violet and lighten up as the season progresses; dark green foliage. 18-24 inches tall.
‘Purple Rain’ (Astilbe chinensis ‘Purple Rain’). A mid-sized astilbe, growing 18-21 inches tall with fluffy lavender to magenta mid-summer blooms.
Unusual Foliage:
‘Chocolate Shogun’ (Astilbe x arendsii ‘Chocolate Shogun’). Early spring, blush-pink flowers atop glossy, chocolate brown to bronze foliage. 20-24 inches tall.
‘Dark Side of the Moon’ (Astilbe ‘Dark Side of the Moon’). Raspberry purple flowers on top of rich, deep, chocolate brown leaves. New foliage is yellow. Grows 20-22 inches tall with a spread of 24-28 inches.
‘Delft Lace’ (Astilbe ‘Delft Lace’) Long apricot-pink flowers on red stems, atop green foliage accented with red. Grows 24-36 inches tall and blooms in early summer.
‘Mighty™ Chocolate Cherry’ (Astilbe chinensis ‘Mighty™ Chocolate Cherry’). A 4-foot tall and wide astilbe with raspberry-red flower spikes, dark red stems and chocolate-colored foliage. Mid- to late summer blooms.
Landscape Design Ideas for Astilbe
Landscaping under a roof overhang: pink astilbe planted with creeping mazus (Mazus reptans), sweetbox (Sarcococca hookeriana var. humilis) and a dwarf oakleaf hydrangea (Hydrangea quercifolia ‘Pee Wee’).
Massing: Astilbes look great when planted in mass, making a bold impact with their flowers and foliage.
Shade Garden: Combine astilbe with other plants that like moist, partly shaded conditions - Japanese painted ferns, Autumn Brilliance ferns, heucheras, hostas and hydrangeas.
Water’s Edge: Plants astilbe alongside a shady stream or pond, where the feathery plumes and delicate foliage will soften the water’s edge.
Stylized Woodland Garden: Incorporate astilbe into a naturalized woodland planting with rocks, Christmas ferns (Polystichum achrostichoides), Alumroot (Heuchera americana), and a purple-leaved bugbane (Cimifuga ‘Chocoholic’) for contrast.
Formal Borders: Create a structured border with astilbe to add a touch of formality to your landscape design. Choose a single color and combine with small leaved evergreen shrubs like boxwoods.
Asian-inspired Garden: The feathery plumes of astilbe combine well with rocks, moss, and evergreen specimens in an Asian-inspired garden design.
Planting Companions for Astilbe
Alumroot (Heuchera americana)
Autumn Fern Brilliance (Dryopteris erythrosora ‘Brilliance’)
Bugbane (Actaea racemosa; formerly Cimicifuga)
Everillo Sedge (Carex EverColor® ‘Everillo’)
Christmas Fern (Polystichum acrostichoides)
Japanese Painted Fern (Athyrium niponicum ‘Pictum’)
Himalayan Sweet Box (Sarcococca hookeriana var. humilis)
Mountain Hydrangea (Hydrangea serrata)
Oakleaf Hydrangea (Hydrangea quercifolia)
Toad Lily (Trycyrtis species)
Turtlehead (Chelone species)
Image credit: Ember Navarro
Why is My Astilbe Turning Brown?
Several factors can contribute to astilbe leaves turning brown. Here are some common reasons for browning in astilbe plants:
Watering Issues: Astilbes prefer consistently moist soil. If the soil becomes too dry, especially during hot periods, the leaves can turn brown and crispy.
Sun Exposure: Astilbes like partial to full shade. Excessive exposure to direct sunlight, especially in hot climates, can scorch the leaves, turning them brown.
Transplant Shock: Astilbes can experience stress after transplanting. If the plant was recently moved, it might take some time for the roots to establish, and browning may occur temporarily.
Soil Conditions: Astilbes prefer well-draining, humus-rich soil. Compacted or poor-quality soil can affect the plant's health, leading to browning.
Fertilization Issues: Astilbes benefit from regular fertilization, but excessive use of fertilizer, especially high-nitrogen varieties, can lead to burnt or browned leaf edges.
Disease: Fungal diseases such as leaf spot or powdery mildew can cause browning of astilbe leaves. Ensure good air circulation and avoid overhead watering to avoid these problems.
Pests: Although astilbe are incredibly pest and disease resistant, occasional problems may occur. Insects like aphids or spider mites can cause damage to the leaves, leading to browning. Inspect the plant for pests and treat accordingly.