The cushion aster or autumn aster (bot. Aster dumosus) has its name for a reason: between early September - although some varieties bloom from August onwards - and November, the low-growing and cushion-forming perennial shows its lush flowers. The uncomplicated plant also impresses with its variety of varieties and can therefore be found not only in many ornamental and front gardens, but also in public gardens and parks.
What is a cushion aster and what care does it need?
The cushion aster (Aster dumosus) is a low-growing, cushion-forming perennial that shows its lush, star-shaped flowers in various colors between September and November. It prefers sunny locations and humus-rich, well-drained soil. Regular pruning promotes dense growth and lush flowering.
Origin and distribution
The cushion aster (bot. Aster dumosus) originally comes from North America, where the plant, which belongs to the daisy family (Asteraceae), is still widespread in its wild form today. However, the wild species cannot be found in our ornamental gardens. Instead, mainly crosses between Aster dumosus and Aster novi-belgii are planted, some of which are classified by British botanists as smooth-leaf asters (Aster novi-belgii).
Usage
Cushion asters can be used for many purposes in the garden. The vigorous plant is primarily used for beds, borders and borders in sunny locations, but the late-flowering perennial is also often planted in rock gardens. Furthermore, it is a typical grave plant, as it quickly forms dense carpets and thus grows attractively over larger areas. Cushion asters look particularly pretty in combination with tall autumn asters as well as with perennials and grasses such as angel hair (bot. Stipa tenuissima) and reddish-brown switchgrass (bot. Panicum virgatum).
Appearance and growth
The different varieties of the vigorous perennial reach a height of between 20 and 60 centimeters and grow quickly, densely and compactly. The cushion aster spreads out in dense mats via its rhizomes, which is why it is very suitable for greening larger areas. The plant is considered to be very propagative, as even the smallest pieces of root grow into new plants. For this reason, larger plantings are difficult to remove, as new cushion asters can still sprout from the old location even years later.
leaves
The lanceolate, pointed leaves of the cushion aster can be between five and 15 centimeters long and typically have a smooth edge. However, there are also varieties with toothed leaves. He althy foliage has a strong, dark green color.
Bloom and flowering time
The botanical name of the cushion aster comes from the Latin word “astrum”, which means “star”. In fact, their flowers, which are around two to five centimeters in size, are very similar to small stars: Numerous elongated, radiating petals emerge from the often yellow center of the flower, which shine in a wide variety of shades from violet, blue, pink, crimson to white. The very numerous flowers often form a dense carpet during the autumn flowering period, which makes the garden shine late in the year - most varieties bloom between August and October. With good care and appropriate weather, the splendor of the flowers can still be admired in November.
Toxicity
Like other types of garden asters - with the exception of the animal-poisonous chrysanthemums - cushion asters are completely harmless to both people and animals. Quite the opposite: the colorful flowers are even edible and can be used to decorate desserts and salads, for example.
Location and soil
Plant the cushion asters in a location that is as full of sun and protected from wind as possible. In principle, the perennials also thrive in bright, semi-shady places, but they produce fewer flowers there and are more susceptible to diseases. The ideal soil is fresh, but not wet (never plant cushion asters in depressions as water collects here!), and also loose and nutrient-rich. A humus to sandy-loamy subsoil is optimal, but it must be well-drained. However, you can easily loosen up heavy, clayey soil with gravel and humus soil.
Advance
You don't have to buy cushion asters as ready-made plants, you can also grow them yourself from seeds. You should sow the fine seeds in early spring in a bowl filled with potting soil or in small pots. Place it warm and bright at around 18 to 21 °C and keep the substrate slightly moist. Since high humidity promotes germination, stretch a translucent film or something similar over the cultivation container. The seeds germinate after about two to three weeks and then very quickly develop into strong young plants. However, these should only be planted in the bed after the late frosts, as they are still quite sensitive.
Planting cushion aster correctly
For the desired carpet-like growth, you should plan around three to four plants per square meter, as the optimal planting distance is approx.50 to 60 centimeters. Whether you want to plant different colors together or create a bed with a uniform color is entirely up to your taste. Regarding the planting date, you can generally plant cushion asters all year round, as long as the weather is mild and the ground is not frozen. This is possible because the perennials are mostly sold in containers or pots. However, it is best to plant the plants in the ground in late spring - after the Ice Saints - or in early autumn.
The planting depth should roughly correspond to the pot depth because the plants must not be placed deeper in the garden soil than they were previously in the planter. Enrich the excavation with mature compost/compost soil and generously cover the planting area with bark mulch. This not only provides additional nutrients through the rotting process, but also prevents the soil from drying out quickly on dry and/or hot days. Don't forget to water the cushion asters thoroughly after planting!
Watering cushion aster
Cushion asters like it slightly moist, but not wet. You should therefore ensure sufficient water supply, especially on dry soils and in hot weather. The soil should not dry out, but it should not become waterlogged either - the popular perennials don't particularly like either. Always water directly onto the ground, never from above or over the leaves - this promotes the development of powdery mildew, a fungal disease typical of asters.
Fertilize cushion aster properly
Fertilize the cushion asters twice a year with mature compost and horn shavings (€52.00 at Amazon). The first time you should provide the plants with budding is in spring, the second time after flowering. Alternatively, you can also use a complete fertilizer for flowering plants for garden plants; potted plants cannot be supplied with nutrients organically anyway because of the lack of microorganisms in the soil.
Cut pillow aster correctly
So that cushion asters bloom lushly for a long time, you have to cut them back regularly - the perennials tend to age. To do this, regularly remove dead plant parts and faded shoots and cut the plants back completely before the first frost. Alternatively, pruning is also possible in spring, which offers the advantage of better winter hardiness: Cushion asters that are not pruned in autumn generally tolerate subzero temperatures better.read more
Propagate cushion aster
You should dig up and divide the cushion asters about every two to three years. This promotes dense and bushy growth, as after a while the perennials only produce a few new shoots. Otherwise, you don't have to worry too much about propagation, because Aster dumosus itself provides abundant offspring through numerous root shoots. It is best divided in spring or early autumn. The plants should then be moved separately to a new location.
Wintering
In principle, cushion asters are hardy, but you should cover young, sensitive plants with a layer of bark mulch or spruce or fir branches during the cold season. This also applies to specimens cut back in autumn. Remove the cover in good time in spring so that the plants can sprout again. Now is also the right time for starting fertilization.
Diseases and pests
Basically, cushion asters are quite insensitive to pests and diseases. However, fungal diseases such as powdery mildew and aster wilt are more common in damp to wet and/or dark locations. For both diseases, you should remove infected plant parts and dispose of them with household waste. In addition, watering and spraying with a home-made horsetail broth helps prevent fungal diseases or suppress them in their early stages. However, if the stock can no longer be saved, you should no longer plant cushion asters in this location.
Tip
Cushion asters also look very pretty as cut flowers in a vase, especially in a mixed bouquet with other species.
Species and varieties
The aster genus includes around 150 different species, which are mainly widespread in Europe and Asia. The cushion aster, also known as autumn aster or bushy autumn aster, which is very popular in many ornamental gardens due to its vigor and numerous basket flowers, impresses with its immense variety of varieties. You can choose between varieties of the species and hybrid forms. We would like to introduce you to some of the most beautiful varieties for your home garden here.
- 'Apollo': growth height up to 40 centimeters, initially white flowers that fade to pink
- 'A feast for the eyes': growth height of up to 30 centimeters, dark purple flowers, very vigorous and persistent hybrid form
- 'Blue Lagoon': growth height up to 50 centimeters, dark purple-blue flowers with a yellow center
- 'Garnet': growth height up to 30 centimeters, pink-red flowers with a yellow center
- 'Heinz Richard': growth height up to 30 centimeters, bright pink flowers with a yellow center
- 'Autumn Greetings from Bresserhof': growth height up to 50 centimeters, pink-white flowers with yellow center
- 'Jenny': growth height up to 50 centimeters, strong purple-red flowers with a yellow center
- 'Kristina': growth height up to 30 centimeters, pure white flowers with yellow center
- 'Mediterranean': growth height up to 40 centimeters, strong blue to blue-violet flowers
- 'Nesthäkchen': low growth, carmine-red flowers
- 'Kassel': growth height up to 40 centimeters, bright red flowers with a yellow center, very vigorous and persistent hybrid form
- 'Peter Harrison': growth height up to 40 centimeters, strong pink flowers with a yellow center
- ‘Prof. Anton Kippenberg': growth height up to 40 centimeters, blue-violet flowers
- 'Sapphire': growth height up to 40 centimeters, violet-blue flowers with a yellow center
- 'Snow Cushion': growth height up to 30 centimeters, white flowers
- 'Starlight': growth height up to 40 centimeters, purple-pink flowers with yellow center
- 'Dwarf Heaven': growth height up to 40 centimeters, light purple flowers with a yellow center
