Scabiosa: sowing, hardiness & toxicity

Regina
Regina
Regina
Regina

I studied horticultural sciences at university and in my free time you can find me in my own patch of land, growing anything with roots. I am particularly passionate about self-sufficiency and seasonal food.

Favourite fruit: quince, cornelian cherry and blueberries
Favourite vegetables: peas, tomatoes and garlic

Scabiosa is a native plant that is well suited for planting in perennial beds, rock gardens and naturalistic gardens. We give tips on choosing varieties, care and propagation of scabiosa.

Scabiosa
Scabious plants are bee-friendly flowering plants with a sweet fragrance [Photo: demamiel62/ Shutterstock.com]

Scabiosa (Scabiosa) is a graceful flowering plant, especially suitable for steppe beds and rock gardens but also for magnificent herbaceous borders. With us you will learn everything about sowing, planting and care, as well as the choice of varieties and different species of scabiosa.

Scabiosa: flowering, origin and characteristics

The scabiosa belongs to the subfamily of the card family (Dipsacoideae), which used to form its own family but is now included in the honeysuckle family (Caprifoliaceae). There are more than 80 species of scabiosa belonging to the genus Scabiosa, of which less than 10 species and a few hybrids are found in our gardens as ornamental plants. Wild scabiosa are found in Europe, Asia and Africa. Scabiosa is also known by the rather unflattering term scabious and pincushion flower.

Scabiosa pink flowers
Flower stems stretch up from a rosette of leaves when the scabiosa is in bloom [Photo: Lea Cabrera/ Shutterstock.com]

Scabiosa reach a height of growth of about 20 to 90 cm, depending on the species and variety. They form basal leaf rosettes, from which the thin flower stalks later extend upward. The leaves of the scabiosa are undivided and coarsely lobed at the base, while the opposite leaves on the flower stalk are more delicate and pinnate. The terminal flower heads are each enclosed below by a wreath of green bracts. The centrally placed flowers are tubular while those at the edge have petals that become enlarged towards the outside. The colour palette ranges from white to yellow to shades of red, pink, purple and delicate sky blue. The flowering period of Scabiosa extends from July to October. The flowers have a sweet scent reminiscent of honey and attract numerous insects with their nectar and some pollen. Therefore, scabiosa is often encountered in bee pasture seed mixtures. After pollination, the cylindrical, furrowed, cup-shaped seeds of the scabiosa with a star-shaped appendage are produced.

Is the Scabiosa perennial? The large genus of scabiosa includes annual and perennial plants. So how long a plant can remain in the flowerbed all depends on the species, although, annual scabiosa often reproduce strongly by self-seeding.

What is the difference between scabiosa and widow flower? Under the term widow flower two at first sight identical-looking plants are summarised: The scabiosa and the knautia (Knautia). They are related generally, although knautia is far more often called widow flower than scabiosa. The biggest difference is the number of petals: the knautia has 4, while the scabiosa has 5 per flower.

Bee visiting Knautia flower
Except for the number of petals, Knautia and Scabiosa are almost indistinguishable [Photo: Tom Meaker/ Shutterstock.com]

The most beautiful varieties and species

Scabiosa are available as long-lived perennials as well as annual ornamental flowers. Below we present the most beautiful species of scabiosa and popular varieties for home gardens.

Pincushion flower (Scabiosa atropurpurea)

Also known as mourningbride, the garden scabiosa has enchanting, brightly coloured flowers and an average growth height of 70 to 90 cm. This is an annual to biennial species of scabiosa found primarily as a summer flower and in flowering mixtures. The flowering period is between July and October. Garden scabiosa self-seeds abundantly in suitable locations, remaining in the bed for years.

  • ‘Barocca’: This globe-flowering scabiosa cultivar with dark red to pink flower colour has bright stamens.
  • ‘Black Knight’: Almost into black go the dark red flowers of this scabiosa. The stamens are creamy white in colour and therefore form a strong contrast.
  • ‘Cherry Red’: This cherry red double flowering variety with white stamens grows up to 70 cm tall.
  • ‘Lavender Blue’: Delicate and sweet fragrance of this large-flowered variety with light purple-blue flowers.
  • ‘Salmon Rose’: Very large flowers up to 6 inches in diameter bloom in this variety in delicate salmon red with a honey-like fragrance.

Tip: The annual ornamental plant is easy to grow from seed and is popular as a colourful mix of varieties under the term garden scabiosa ‘Mammuth’-Mix.

Cherry red Scabiosa
The red Scabiosa ‘Cherry Red’ is a special eye-catcher in the border [Photo: Alex Manders/ Shutterstock.com]

Japanese mountain scabiosa (Scabiosa japonica var. alpina)

Japanese mountain ccabiosa is a low species ideal for planting in rock gardens and alpine gardens. It reaches a growth height of 20 to 30 cm, blooms profusely and forms pretty purple to pink flowers. It can also be planted as a seeding, hardy, perennial groundcover.

Japanese scabiosa in rock garden
The Japanese mountain scabiosa is ideal for planting in the rock garden or alpinum [Photo: Svetlanko/ Shutterstock.com]

Caucasian scabiosa (Scabiosa caucasica)

Caucasus perennial scabiosa is distinguished by its strikingly large marginal petals. This completely hardy scabiosa reaches a growth height of 60 to 80 cm and grows like a clump.

  • ‘Gudrun’: The scabiosa has double, sky-blue flowers. Because it is sterile, it does not spread in the garden by self-seeding but this also means that it provides no nectar for insects.
  • ‘Perfecta’: Lavender blue blooms this variety, which is well suited as a cut flower. Scabiosa ‘Perfecta’ blooms between July and September.
  • ‘Perfecta Alba’: This scabiosa in white is another variety from the ‘Perfecta’ series. The pure white flowers blend well into perennial beds with variegated plants.
  • ‘Stäfa’: This blue scabiosa with wavy marginal petals develops very large flowers up to 10 cm in diameter.
Purple scabiosa flowers
The scabiosa ‘Stäfa’ produces very large flowers [Photo: John R Martin/ Shutterstock.com]

Scabious (Scabiosa ochroleuca)

Scabious is a perennial yellow scabiosa that reaches a growth height of 60 to 80 cm and forms clumps. Especially in southeastern Europe, the species is often found in the wild. This bee-friendly perennial is extremely easy to care for and blooms annually in a delicate lemon to sulfur yellow.

Pale yellow scabious
The yellow-flowered scabious is common in species-rich flowering meadows [Photo: ArgenLant/ Shutterstock.com]

Catchfly-leaved scabiosa (Scabiosa silenifolia)

Probably the lowest scabiosa is the catchfly-leaved scabiosa. With a growth height of 10 to 15 cm, the perennial catchfly-leaved scabiosa is ideal for planting in alpine meadows and calcareous soils. In the wild, it is found in mountainous regions up to 2400 m altitude. It is therefore also a completely hardy Scabiosa species. It forms blue-purple, downy to tomentose flowers.

Star scabiosa (Scabiosa stellata)

Star scabiosa is rarely sown for its bright blue flowers, instead its spherical seed head is popular for floristry and as a dry decoration. It reaches 50 cm in height, is an annual and requires warmth. Growing should be done at 20 °C in the greenhouse or on the windowsill.

Starflower scabious
The starflower scabious is mainly cultivated for its seed heads [Photo: weha/ Shutterstock.com]

Small scabious (Scabiosa columbaria)

Small scabious is a perennial scabiosa with a low, often stocky growth habit between 20 and 50 cm. It is hardy down to about – 23 °C and can therefore do without winter protection in most areas.

  • ‘Butterfly Blue’: Butterflies are attracted to this purple-flowered scabiosa, which is how it got its name. Scabiosa columbaria ‘Butterfly Blue’ grows compact and blooms between July and September.
  • ‘Flutter Pure White’: Pure white flowering scabiosa reaches heights between 20 and 60 cm. It blooms very early, from the end of May.
  • ‘Pink Mist’: A petite scabiosa with a growth height of 20 – 30 cm and pale pink flowers is the ‘Pink Mist’. With its comparatively small flowers, it is particularly suitable as a rock garden perennial.
Scabious pink mist
The Scabious ‘Pink Mist’ grows compact and small [Photo: Debu55y/ Shutterstock.com]

Planting Scabiosa: location, sowing & Co.

The optimal location for scabiosa depends on the species but is generally sunny on well-drained, moderately dry to fresh, humusy and slightly calcareous soils. Planting time for perennial perennial scabiosa is in the frost-free periods in late fall from September to late October or from March. Home-grown plants from seeds of scabiosa are planted outdoors no earlier than after the last frosts have passed in mid-May to June. The planting distance for scabiosa is 35 to 50 cm for clump-forming perennials, depending on the species. Delicate scabiosa likes to be planted in small groups of 3 to 10 plants.

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Planting can also be in the balcony box and pot, the planter should hold at least 10 litres of soil volume. In addition, there must be good water drainage and, at best, a drainage layer of broken clay or gravel. Then fill the planting substrate for scabiosa in the pot. A nutrient-rich potting soil like our Plantura Organic Flower Compost contains all the essential nutrients to promote lush blooms and plant health. The compost-rich, peat-free soil can also be used to improve garden soils. Now place the scabiosa in the soil, no deeper than it was sitting in the pot before, and lightly press the soil all around. After that should be watered generously.

Scabious seedlings
In optimal conditions, the first seedlings of scabiosa appear after 8 – 10 days [Photo: Sheryl Watson/ Shutterstock.com]

Sowing of scabiosa annuals is done from mid-March in the cold frame or at the end of April directly into the open ground from a temperature of 6 to 12 °C. The seeds of perennial scabiosa can also be grown indoors between February and July before planting. For this purpose, seed trays or small pots are filled with a low-nutrient growing medium and the seeds are lightly pressed into it. They should hardly be covered with soil, as they are light germinators. Then water and place the container in a warm place at about 18 °C. Germination generally occurs after about 8 – 10 days. After germination, the plants should be further cultivated at 14 to 16 °C in a slightly cooler place.

Scabiosa flower with butterfly
Fertilisation in spring supports growth and flowering [Photo: Jennifer Bosvert/ Shutterstock.com]

Care

Scabiosa are basically drought tolerant and not very demanding in terms of care. Annual cultivated scabiosa do not require any care except watering. For perennial scabiosa, cut off the dead parts of the plant in the spring before the new shoots. Then you can fertilise with compost or a little slow-release fertiliser, which will stimulate growth and flowering. We recommend the use of a predominantly organic fertiliser for this purpose. For this purpose, use a product such as our Plantura Flower Food. The low-dust granules are spread around the perennial and worked into the surface. Over the course of weeks, soil organisms release the nutrients they contain for the plant roots.

In summer, it may be necessary to tie up dense and tall bushes of scabiosa, so that they do not fall down during heavy rain or wind. If the seed heads are regularly cut out shortly after flowering, this will result in longer and richer flowering. In addition, the scabiosa does not germinate in the bed.

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Are scabiosa eaten by snails? Scabiosa are usually not endangered by snail feeding. However, if there is hardly any other food available or if a lot of molluscs have accumulated in your garden, scabiosa may well get eaten. Various measures will help here if you want to fight slugs.

Is the Scabiosa hardy?

Depending on the species, scabiosa have a low to high hardiness to below -40 °C. Outdoors, you should choose only one variety, either annuals that seed or hardy perennials. In pots that can be wintered frost-free, you can plant more delicate species and varieties of scabiosa.

Propagation

Most scabiosa, except for double varieties, are easily propagated by seed. Many scabiosa self-seed in the bed, if not removed in time the seed stand. However, this can lead to cross-breeding of the varieties, so that different flower colours and growth characteristics appear in the offspring. True to variety, perennial scabiosa can be easily propagated by division. In this process, a portion of the herbaceous perennial is cut off with a sharp spade and moved to a suitable location.

Scabiousa wildflower
In open spaces and suitable locations, scabiosas like to self-seed [Photo: Orest lyzhechka/ Shutterstock.com]

Is scabiosa poisonous?

Scabiosa is not poisonous but it is not called an edible wild herb either. However, it probably has some medicinal characteristics, which is why it is sometimes still listed among medicinal plants. In earlier times, the herb of Scabiosa and Knautia was used to relieve itching from scabies, hives, and other skin conditions such as neurodermatitis. This is where the nickname “scabious” comes from.