Foliage and blossoms work to help the shade loving Astilbes give a naturalized feeling to the garden. The individual blooms of this perennial are clustered high on the tall stem and look like plumes. The hybrid of the Far East native flower that grows in US gardens blooms in early summer.
Astilbes appear as fluffy spikes of white, purple, red and pink above delicate leaves of bronze or green. As the fernlike leaves appear in the garden, they are glossy. As the growing season progresses the foliage loses the shine.
Plant astilbes in partial shade because they are not tolerant to high temperatures. The soil should be moist, slightly acidic and have a high content of organic matter. They will tolerate a wet environment, but are not drought resistant.
Although astilbes are beautiful among other plants in a container, their moisture requirements means that special attention must be given to the container garden so that the soil doesn't dry out. Care must be taken in choosing other plants for the container, making sure that they are able to survive the moist soil that the astilbes need to thrive.
Another consideration when using the showy astilbes in a container garden is the size of the mature plant. It can grow to 4 feet, with a spread of 1 to 3 feet. The pot chosen for the astilbes should be at least a foot deep with a diameter of one to two feet. Place the container in a spot that will allow the roots to stay cool and the soil to retain moisture.
Astilbes are propagated by division. New growth appears at the outside. Every three to five years the astilbes should be dug up, and the newer, outer plants should be cut away and replanted. Division and replanting can be done in the spring or fall.
Plant the astilbes at least a foot apart so that they have plenty of space to grow. The roots are shallow, so don't plant them too deeply.
Once established, astilbes don't need a lot of care from the gardener. The stems are strong enough to grow without staking and the flowers dry beautifully right on the plant, giving the perennial garden an ornamental look, even though the drying blooms turn brown.
With proper attention to the moisture content of the soil, the graceful astilbes will be a favorite in the perennial garden. The gardener can help the soil maintain moisture for the plant with mulch.