The flowering time of the extremely versatile garden beauties varies greatly and extends until autumn. Because while the first asters are already a real eye-catcher in May, the autumn asters still decorate the home garden in September and October. Due to their great diversity, the fascinating plants find numerous uses, whether for rock gardens, flower beds or as cut flowers. While summer asters are annual plants, winter asters are perennials.
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Look
The beautiful flower heads look like a unique large flower at first glance, but it is made up of many small, radial flowers arranged in umbels and forming a colorful wreath. The color spectrum is as diverse as the individual varieties are, ranging from plain white to red, pink, purple and cool blue tones. In addition, asters are available with intensely luminous nuances as well as in delicate pastel tones.
The multifaceted species
Due to the interesting growth forms, asters, which belong to the daisy family, can be used for rock gardens, flower borders and as cut flowers. Low varieties are particularly suitable as area covers, for planters and troughs and as flowerbed borders. Asters that bloom in autumn are ideal for beds of magnificent perennials and natural gardens.
Magnificent asters adorn the home garden throughout the season if the individual varieties are cleverly combined with one another.
spring asters
- like the Aster Alpinus with a growth height of just 10 to 20 cm, which is also often referred to as a dark beauty and is characterized by violet, pink and white tones is perfect for rock gardens, where it forms dense cushions
- Aster tongolensis also shows all its splendor in violet nuances in late spring at a height of 50 cm and forms a beautiful ensemble with lady’s mantle and gypsophila
Sommerastern
Summer asters, which include the mountain asters such as the King George, which shows lilac-colored flowers all summer long from July, are the perfect bedding plants with a growth height of 60 cm and can be planted with yarrow, girl’s-eye and the magnificent hare. The typical summer asters also include the varieties of Aster x frikartii and Aster linosyris (yellow gold hair aster).
autumn asters
Autumn asters, like the cushion asters, bloom profusely and are bedding perennials that grow extensively. These include the Aster dumosus, which grows to a height of 20 to 25 cm and has dark purple flowers, as well as the popular Aster dumosus Kassel with red to purple flowers. The myrtle asters (Aster ericoides) enchant the garden well into November, for example the smooth-leaf asters (Aster novibelgii) and the tall tawny asters (Aster novae-angliae), which reach an impressive height of up to 150 cm and are wonderful with chrysanthemums , monkshood and sedum harmonize.
winter asters
Winter asters are also known as autumn chrysanthemums (Dendranthema hybrids), gold flower or usenflower and adorn the beds in the fantastic shades of orange, yellow, pink, white and red until the end of November.
origin and soil
The home of the attractive daisy family is North America, where they grow wild from Newfoundland to Georgia and line the banks and riverbanks as lush tall perennials. The soil is adapted to the conditions and is therefore well drained and rich in nutrients. This is why asters feel most at home in our gardens:
- in loose, permeable
- and nutritious soil
- containing sufficient compost
- the soil for cushion asters, on the other hand, can be loamy
- a mixture of loam and sand is ideal for white asters
location
With a few exceptions, asters are not particularly demanding and prefer:
- a sunny place
- In contrast, the wild asters like the white wood aster (Aster divaricatus) and the blue wood aster (Aster cordifulius) like it in half shade.
- and smooth-leaf asters should be predominantly airy
Because this variety is prone to powdery mildew when it rains and can only dry its leaves in airy places.
Fertilize
The impressive plants can last for many years if they are covered with organic fertilizer such as compost rich soil that contains all the necessary nutrients every spring and fall. If no compost is available, phosphorus-containing flowering fertilizer can be used as an alternative. However, fertilization is always moderate and not too high in nitrogen, since too much nitrogen makes the plant susceptible to mildew and the tissue becomes soft. While artificial fertilizers should never be used, nettle broth is ideal.
pour
Asters require regular watering as they prefer slightly moist soil and should be watered according to their needs. Autumn asters are well watered in the dry season, as are smooth-leaf asters, which form yellow leaves and bare stalks if there is too little moisture.
The cutback
Perennial plants of these daisy family develop into large bushes over time and accordingly require more space. To prevent this, the shoots can be cut back to just above the ground in spring. If the borage and smooth-leaf asters are pruned in summer, the stems will branch out and the dreamy perennials will not only bloom richer and longer, but also later. To achieve this, the perennial bushes are cut back by a third in June. If, on the other hand, no pruning is carried out, long plant stems with fewer flowers will form. The aster gets new strength if you regularly remove faded stalks.
untie
Autumn asters that are planted individually in the bed do not have the necessary stability and can be supported with perennial holders or a stick that is covered by the leaves until flowering. However, if several perennials were planted in graded heights, these daisies support each other.
propagation
Since some of the wonderful aster varieties grow quite luxuriantly, propagation by root division is a good idea:
- Division takes place only after flowerin
- to do this, divide the eyrie into individual pieces with a knife
- Completely remove woody and older shoots
- and trim off injured roots
- each section has 1 to 2 young, healthy leaf tufts
- planted in the ground or in pots
- Keep plant substrate well moist
- this way, weakened plants due to root loss in the summer heat cannot suffer from a deficiency
- Division ideally every 3 to 4 years
The division of late-flowering asters should be done in the spring and not immediately after flowering so that the plant has enough time to establish itself before the cold onset.
Another variant of propagation is sowing
- prefer asters in the pot from March to April
- with 2 to 3 seeds in the seed pot
- in a warm, bright place
- at temperatures of 18 to 21 degrees
- or at 10 to 15 degrees
- which slows down the germination process but produces strong seedlings
- if more seed is used then prick out
- Direct sowing from mid-May also possible in beds
- with max. 2 seeds per planting hole
- at a maximum depth of 1 cm
- Germination after about 14 to 20 days
- Plant out in flower beds or pots only after the ice saints
Plant all year round
Asters, which are available as perennials, can be planted year-round as long as there is no danger of frost.
But beware! Myrtle and borage asters enjoy special treatment when planting and must not be planted too deep, otherwise the buds may die or rot.
This is how asters overwinter
In order for the colorful plants to survive the winter, appropriate protective measures must be taken:
- Always cut back in spring
- because the shoots offer very good winter protection
- cover with fir branches or brushwood during long and very cold periods of frost
- so no frost penetrates to the root ball
- The following applies: the thicker the cover, the better the winter protection
diseases and pests
In midsummer, asters can be attacked by the pollen beetle, a small black beetle. However, since this only affects the plant for a very short time and does not cause any damage, you should avoid treating it with chemical agents.
It is different with diseases
One of these is aster wilt, which occurs quite frequently and mainly in cushion asters and is indicated by a brownish to black discoloration of the foliage. To date, there are no countermeasures to save the infested plant, so it can only be disposed of with the attached soil. But beware! Never on the compost otherwise the fungi will get back into the ground because diseased plants belong in the bio bin or in the garbage.
The fungal disease can only be successfully prevented by:
- an annual bed change
- after planting, sprinkle bedrock dust around the young plants
- if it gets on the plants, wash it off with horsetail broth
- Repeat this process 2 to 3 times over the course of the year
When the weather is appropriate, asters tend to develop powdery mildew, which is visible as a mealy white coating primarily on the upper side of the leaf but also on the flowers and buds. If the infestation is too severe, the leaves will die. In addition to chemical fungicides from specialist shops, you can use ordinary milk. Because Australian researchers discovered microorganisms in the milk that successfully combat powdery mildew. In addition, the sodium phosphate it contains prevents recurrence of the disease and also strengthens the defenses of the noble plant.
As a preventive measure against powdery mildew, horsetail tea also helps, as the silica it contains also protects the interesting perennials.
