Are you still looking for a flowering autumn plant for your garden that is insect-friendly? We introduce you to the Herbstaster. There are numerous colors that show up in the last days of summer at the beginning of their flowering.
Autumn also has a lot to offer when it comes to gardens. Autumn asters (Symphyotrichum and Aster) are an excellent example of a beautiful floral display - they come in many different colours. In this article we will inform you about what needs to be considered when planting and caring for autumn asters.
Tip: Many asters used to belong to the genus Aster but have been reclassified to the genus Symphyotrichum convicted. However, some well-known garden asters are still called botanically correctly Aster.
Herbstaster: origin and characteristics
Asters from the genus Symphyotrichum originally come from North America and Canada. The genus Aster , on the other hand, is native to Eurasia. Plants of both genera have long been found in local gardens and delight with their late summer flowers.
With a species-dependent growth height of 20 to 140 cm and a width of 30 to 90 cm, the hardy perennials are a visual eye-catcher in the garden . The herbaceous plants have lanceolate, entire, smooth or rough leaves.
The radial flowers can be colored from white to light pink to violet, depending on the species and variety. The yellowish stamens are in the middle. Insects like bees and bumblebees are doing you a favor by planting Japanese asters. They are rich in nectar and are frequently flown with, especially the native mountain aster.
When do Japanese asters bloom? The flowering period of Japanese asters is from early September to November.
Tip: Occasionally, asters and chrysanthemums (Chrysanthemum) are confused because they are very similar. Both genera belong to the daisy family (Asteraceae). But there is a big difference between autumn asters and chrysanthemums: the latter are usually nothardy.
The most beautiful autumn aster species
There are different types of autumn asters with very different flower colours. Below we present a few selected ones:
Pillow Aster (Symphyotrichum dumosum)
As the name suggests, the cushion aster grows like a cushion and forms a hemisphere. Due to the squat growth, this variety reaches a maximum height of 20 to 40 cm. The flowers are pink to violet depending on the variety. For a sea of flowers, ten to twelve plants can be planted per square meter, alternatively leaving a distance of 30 cm between them.
Myrtle Aster (Symphyotrichum ericoides)
The myrtle aster has a bushy habit with upright stems and clumps growing to a height of 50 to 100 cm. The flowers are small and white. Due to the narrow growth width of 45 to 50 cm, four to six plants of the myrtle aster can be planted per square meter or a planting distance of 45 cm is maintained.
Flatleaf Aster (Symphyotrichum novi belgii)
The 'Permanent Blue' flowers blue-violet. It reaches a maximum height of 70 to 140 cm. The growth is bushy, the plant forms short runners. In contrast to the other species presented, this one needs moist soil. The growth width is about 70 to 80 cm. For this reason, only one to three plants should be planted per square meter, or a planting distance of 80 cm should be ensured.
Aster (Symphyotrichum novae angliae)
The varieties of the borage aster mainly flower in pink to pink tones. The flowers are very large at 10 cm. The growth is clumpy. A growth height of 50 to 100 cm is reached. The leaves are finely hairy and soft. This species grows extremely wide at up to 90 cm, so plants should be spaced 90 cm apart.
Mountain aster (Aster amellus)
This very bee-friendly aster grows bushy to a height of between 30 and 60 cm. The flowers are pink to blue-violet and small. Due to their maximum growth width of 40 to 50 cm, plants of this species shouldplanted about 45 cm apart or four to six plants per square metre.
Wild Aster (Aster ageratoides)
A very drought-resistant aster species that grows sprawling and tall - the stature height is between 70 and 100 cm. Mostly light violet rather small flowers. The leaves are lanceolate and rough. The planting distance should be about 60 cm, or a maximum of two plants should be planted per square meter.
Planting autumn stalks: location, sowing and Co.
Autumn stalks like a sunny spot. If there is too much shade, the blooming joy of the autumn perennial decreases. The soil must be rich in nutrients, permeable, rather mineral and dry to fresh, since autumn asters do not tolerate soil that is too moist. If your soil is very clayey, you should loosen it up with sand. A very sandy soil, on the other hand, must be touched up with earth. Our peat-free Plantura organic compost is suitable for this. It has a high humus content and thus stimulates soil activity and provides a good supply of nutrients. This in turn ensures lastingly beautiful, lush plants. This soil is also recommended for pot planting.
When should you plant Autumn Asters? Autumn Asters are sold in containers and can be planted on frost-free days between spring and autumn. They are sold in large numbers shortly before they bloom in late summer. Then plant the autumn asters directly.
Tip: Ornamental grasses, larkspur (Delphinium) and phlox (Phlox) are suitable as planting partners for autumn asters in perennial beds ).
Planting autumn stalks in pots or balcony boxes:
Some varieties are not suitable for planting in pots because they grow too tall. But compact varieties like the cushion aster do well on the balcony. Plants should be planted about 10 cm apart from each other. A rain-protected place is also recommended, as this also reduces the risk of infection by powdery mildew. It is also important that there is a drainage layer in the pot so that the soil is not permanently too damp for the autumn aster.
Care for autumn stalks
Autumn stalks are easy to care for andfrugal. However, a few points should be observed during maintenance.
Pruning, watering and fertilizing of autumn stalks
Right after flowering, the autumn aster can be cut back by about a third of its height. Since the stems of the plants serve as winter protection, they should not be cut off close to the ground. In addition, the hollow stems offer insects a place to hibernate. The autumn aster can also be cut back in spring, around March or April. The plant will then sprout again near the ground.
Tip: To get a lush picture throughout the flowering period, cut off wilted flowers immediately. This stimulates the autumn asters to grow again.
The autumn aster should be watered in such a way that the soil is not too damp. The irrigation water should not be poured over the plant, but only the soil should be wetted with water. Asters only need occasional watering when the drought persists or on very sandy soils. Only the smooth-leaf aster should always be kept moist.
Fertilization is recommended annually in spring. This keeps the soil rich in nutrients and allows the plant to grow optimally. For example, our Plantura organic flower fertilizer is suitable for this, the nutrient ratio is designed for magnificent flowers. The very high proportion of organic components promotes he althy soil life, which sustainably strengthens root growth. In addition, the high potassium content prevents fungal diseases such as mildew and ensures a stable footing.
Control of powdery mildew on autumn asters
Powdery mildew on autumn asters is easy to recognize. The leaves are covered with a white-grey layer on top. As a result, the plant can no longer carry out sufficient photosynthesis, and the fungus also feeds on assimilates and nutrients. As a result, the autumn aster grows poorly and produces fewer flowers. Various causes can promote an infestation. The fungal infection usually occurs on cool, dewy nights - this can also be the case when the weather is otherwise dry and warm. Asters that are shaded in the morning and plants that are close together are particularly at risk. Poor air circulation and leaves that are damp for a long time in the morning promote the development of the fungal disease. Underfed asters are also more susceptible than young plants.
The affected parts of the plant must be cut off when mildew first appears. This not ondispose of it in the compost, but directly in the household waste. The plant can then be gently treated with milk or baking powder.
Read our dedicated article to learn more about powdery mildew detection, prevention and control.
Are asters poisonous?
Autumn stalks are non-toxic to humans and pets. On the contrary, the flowers are used as a decoration for dishes and are edible, as are the leaves. However, they should not be eaten immediately after purchasing the asters, as they may be contaminated with fungicides or other pesticides.
In addition to the autumn aster, there are other plants that flower in autumn. In our special article, we present other of the most beautiful autumn flowers in addition to the aster.