Overview and Description:
Astilbe plants have long-blooming, plume-like flowers in soft shades of white, pink and red. The flowers are held on tall, stiff stalks, above the airy foliage. Astilbes are one of the easiest perennial flowers to grow, but they give a high return. Virtually pest free, they can light up the shade garden or soften a sunny spot.
- Leaves: Astilbe foliage tends to be basal, with deeply toothed leaflets of alternately compound leaves.
- Flowers: Feathery plumes of flower clusters are born on tall stalks above the foliage. Astilbe flowers come in shades of creamy white, pink, lavender, and red, and stay in bloom several week, slowly fading in color as they dry.
There are several species and cultivars within the Astilbe genus, with variety in the flower plumes; some spikier or fluffier than other. Most of the popularly sold Asitlbes are hybrids resulting from crosses between the species.
False Spiraea, False Goat's beard, Meadowsweet
Astilbe are widely adaptable and are hardy from USDA Zones 4-8. In hot, dry climates, they need to be planted in the shade.
The size of mature plants will depend on the variety being grown as well as the growing conditions. You can find tall Astilbe as well as dwarf plants, ranging in size from 1 - 4 ft. (H) x 1--3 ft. (W)
Astilbe will bloom in shade, but the plants prefer some sunlight to achieve their full size. However, in hot weather and dry soils, their foliage will burn and partial shade is preferable.
Bloom Period/Days to Harvest:
Different varieties will bloom anywhere from mid-spring to late summer. If you plant different types of Astilbe, you can prolong the bloom almost all season.
The plumes remain in flower for several weeks and continue to look good as they fade and dry on the plant. No deadheading is needed.
There are new varieties being introduced every year and recently they've begun breeding for darker foliage. Some established standards include:
- Astilbe arendsii 'Bridal Veil' - Mid to late season bloomer with full white plumes (3 ft.)
- Astilbe arendsii 'Fanal' - blooms early with blood red flowers on bronze foliage (1 - 2 ft.)
- Astilbe arendsii 'Rheinland' - Another early bloomer in a rich pink, very hardy (2- 3 ft.)
- Astilbe chinensis taquetii 'Purple Candles' - Deep purple, chenille-like plumes ( 3 - 4 ft.)
- Astilbe chinensis Visions in Red - Compact plant with bronze foliage and deep red fowers. (1 - 2 ft.)
Great long-lasting color for shade or partly sunny borders. Provides a nice textural contrast to plants with large, broad leaves like Heuchera, Hostas, and Ligularia. Astilbe can also be grown in containers.
Soil: Astilbe prefer a slightly rich, moist soil. The warmer the weather, the more moisture they need, especially in full sun. They also prefer a slightly acidic soil pH of around 6.0.
Planting: Astilbe seed is available, but it can be difficult to germinate.
It's easiest to start with a plant or division. Even a small plant will quickly fill out and perform well in its first year. You can plant in either spring or fall, but try and avoid planting in the hottest part of summer. If you must plant then, keep the plant well watered until you see new growth emerging.
Extremely little maintenance is required of Astilbe plants. No staking or deadheading is necessary. The flower heads will dry on the plant and remain attractive for many months. The flowers can be cut whenever they start to look ragged or left up for winter interest and cut back in the spring.
The biggest need Astilbe plants have is some relief from hot, dry weather. Either provide afternoon shade or extra water. They do not handle prolonged periods of drought well; the leaves will brown and dry and if left dry too long, the plants will die.
Divide every 4-5 years, to keep the plants healthy. Astilbe plants can grow quickly, if they are given ideal conditions. More frequent division may be necessary. Keep the plants well watered after replanting and they will re-establish themselves quickly.
Pests & Problems:
Astilbes are virtually trouble free, bothered by few diseases or insects. The tender, new growth may be nibbled on by groundhogs or rabbits, but once the plants have filled out, the plants were no longer bothered.