The borage aster conjures up color in your garden when most of the other flowers have already faded. However, she needs some care.
The borage aster, known by botanists as Aster novae-angliae, conjures up an attractive splash of color in the autumn garden with its purple, pink and white flowers in flower borders. For flower lovers who want to lovingly design their garden until late autumn, it is one of the garden beauties that absolutely belong in a bed.
Origin of Aster novae-agliae
The borage aster is commercially available under the name Symphotrichium novae-angliae. Because of its disease resistance, it is a very popular perennial among hobby gardeners who want a pretty and colorful sea of flowers in the fall. Unlike the smooth-leaf aster, the predatory-leaf aster has hairy, velvety leaves. The name that is used for the perennial in Germany says it all. The borage aster belongs to the daisy family. Its original home is the east coast of North America, which is why it is also referred to in botany as Aster novae-angliae. Translated, this name means "New England aster". Their preferred locations are forest edges and river banks where the soil is very moist.
Appearance and growth of the borage aster
Aster novae-angliae is a robust perennial with numerous sprouts and powerful shoots. It grows bushy and the branches are about halfway covered with dense foliage. The perennial does not form any runners from its rootstock. The tawny aster can reach a height of 120 to 240 centimeters.
» Foliage of Aster novae-angliae
The leaves of the borage aster have an entire margin, range in color from green to grey-green and are lanceolate in shape. They are provided with a velvety hair and feel a little rough. Their length can be up to five centimeters. In autumn, branches appear in the upper part of the shoots, from which broad, complex and multi-part inflorescences develop.
» Flowers and Seeds
In the period from September to October, the borage aster shows itsmagnificent flowers. They have a diameter of two to four centimeters, with the appearance of the classic daisy family. The Aster novae-angliae presents itself with 50 to 90 narrow rays, which, depending on the aster variety, appear with violet, reddish or pink colored ray florets. The pistil or yellow disc in the center consists of tiny and fertile tubular flowers. The flowers have green and protruding bracts that are just as velvety as the other leaves of the Bigleaf Aster.
A special feature of the Aster novae-angliae is that, in contrast to the smooth-leaf aster, it closes its pretty flowers at night and in cloudy weather. In technical jargon, this is also referred to as the “sleeping position”. Due to the stiff growth and this characteristic, the raptor leaf aster is less popular than other aster species such as the smooth leaf aster. Especially in autumn cloudy and rainy weather sets in quite often and the Aster novae-angliae does not always show its full blaze of colour. This property is no longer present in newer varieties of the tawny aster, so that the perennial shines in an enchanting bloom all the time.
The seeds of the borage aster form reddish-white crowns of feathers, which are also known as pappus and are pretty to look at.
The borage aster varieties and their characteristics
There are numerous Aster novae-angliae varieties that are available on the market and have special properties. The different colors of the flowers bring an enchanting splash of color to any garden when almost all the other flowers and perennials in the beds have faded.
Aster Alma Pötschke
This is a tried and tested variety that has a compact growth habit. It grows between 80 and 90 centimeters in height and presents itself with a sea of cherry-red flowers.
Aster Paul Gerber
This Aster novae-angliae belongs to the mid-early varieties, with numerous flowers that are purple-pink. It grows up to 120 centimeters in height and is considered he althy and stable.
Aster Barr's Blue
The aster variety has large, blue-purple flower heads that can be up to five centimeters in diameter. The perennial can grow up to 120 centimeters in height.
Borgwort Aster Barr's Pink
It is a robust variety that presents itself with pink, large flowers and up to 150Inches high.
Bolivia Harrington's Pink
If you want a tawny aster with bright pink flowers for the garden, you should choose this variety. It reaches a height of up to 150 centimeters.
Bolivia Aster Autumn Snow
This aster is the only one that has white flowers. The early flowering variety is covered in flowers and closes the flower heads in the garden in the evening. If they are placed in a flower vase as a table decoration, this does not happen. This predatory leaf aster has a growth height of 120 to 150 centimeters.
Aster Rosa Sieger
This variety has flowers that are more than five centimeters in size and glow pink. The perennial reaches a height of 130 to 140 centimeters.
Roughleaf Aster Rudelburg
The variety, which grows to a height of around 110 centimetres, has salmon-pink flowers that enrich the autumn garden with their special luminosity.
Burgundy Aster Purple Dome
The perennial has a compact and rounded habit. It is one of the smaller varieties and only reaches a maximum height of 60 centimeters. This Aster novae-angliae was found on a roadside in Pennsylvania. Her flowers are covered with purplish-purple petals.
Aster Violetta
The perennial captivates with its dark violet, luminous flowers, in which the yellow pistil stands out in a special way. It belongs to the late-blooming tawny asters that bloom on long stems. Due to its height of 120 to 150 centimetres, it is the perfect perennial for the back area in a perennial border.
Preferred location and soil type
The raptor leaf aster loves a sunny spot, but does well in less sunlit areas of the garden.
The aster novae-angliae is relatively undemanding in terms of nutrient supply. It prefers fresh, loamy, humus-rich soil that has a certain amount of moisture and should be rich in nutrients. This ensures that it sprout properly every year and delights the gardener's heart in autumn with a lush bloom of bright colors. During the summer months, the soil must not dry out too much. This affects the development of the flowers and powdery mildew can form.
Planting and caring for borage asters
Because borage asters can also be infested with powdery mildew, a few important factors should be considered when planting and caring for them. The wrong location is chosenand if there is no perfect supply of nutrients, the risk of powdery mildew increases significantly.
» Notes on planting
Burse asters available in pots are planted in spring. This gives them enough time to grow in the summer. In autumn they will show themselves for the first time with a sea of flowers. Since the aster novae-angliae grows quite high and the stems become bare at the bottom over the course of the year, the best place for the borage aster is in the middle or rear area of the perennial bed. The bare, leafless stems can be very nicely concealed with smaller perennials. Due to the tall growth of the Aster novae-angliae, it needs support. Otherwise she is in danger of falling over.
» care instructions
During the hot and dry summer months proper watering is essential. The situation is different with regard to fertilization. Here it is sufficient if the Raublatt-Aster gets a layer of compost in spring. If the shoot tips are shortened by about ten centimeters before the buds form, the flowering time of the Aster novae-angliae can be pushed back a little. The measure makes sense to improve the stability of the perennial. Woody shoots should be removed in the fall, as should faded flowers.
Propagate borage aster
So that the rough leaf aster blooms with great joy and forms new foliage, the perennial should be divided in the spring after two to four years and the parts planted in a new location. To divide the perennial, it is dug up and completely taken out of the ground. First old root parts are removed. Then sections with a few clusters of leaves can be separated from the mother plant. These should be planted in another sunny location with nutrient-rich soil. It is important that the soil is kept well moist during the growth phase.
In addition to dividing, the borage aster can also be propagated by cuttings. Spring is the best time to take cuttings. Only young, fresh shoot tips were used as cuttings. The resulting young plants spend the first year in an unheated greenhouse or in a cold cold frame.
Pests and diseases of the borage aster
Aster novae-angliae is not a favorite plant of pests. At the same time, it is also less susceptible to disease than, for example, the smooth-leaf aster, which is often attacked by powdery mildew. Sometimes, however, mildew can also occur in the rough leaf aster if the wrong location with too littlemoisture and nutrients.
Perfect plant partners for the borage aster in the perennial border
Since the Aster novae-angliae prefers to find its place in the middle or rear part of the perennial border due to its tall growth and often does not have any leaves in the lower area, there is a lot of space left to complete the border with other plants and the to cover bare stems. Beautiful plant partners in the bed are dahlias, sedum and pretty ornamental grasses, which beautifully frame the aster with their long, feathery leaves.