Field scabious: planting, care, bees and price

Field scabious (Knautia arvensis) is a perennial of hay meadows, dykes and road verges. The plant grows 30 centimetres to a metre tall. From June to September, flat, pale lilac-blue flower heads sit on long stems. Field scabious wants full sun and soil where rainwater drains away well. The species is originally native to the Netherlands.

Field scabious at a glance

Leaf

April to October

Flower

June to September

Fruit

no noticeable fruit

JanFebMarAprMayJunJulAugSepOctNovDec

How do you recognise field scabious?

Start at the base. A rosette of long, grey-green leaves grows there, often with a coarsely toothed edge. Higher up the stem, the leaves sit in opposite pairs. These stem leaves are deeply cut, like a feather with narrow segments. Fine hairs cover the whole plant, which gives field scabious a greyish look.

Each long stalk ends in a flower head 2 to 4 centimetres across. The head is fairly flat. Around its edge the florets are larger and point outwards. Every single floret ends in four petal lobes. After flowering, the round seed head soon falls apart.

Small scabious (Scabiosa columbaria) looks very much like it. Count the petal lobes on one floret: small scabious has five, field scabious four. Field scabious also carries long, spreading hairs on the stalk just below the head. Garden centres sell a different species too, Knautia macedonica. Its flower heads are a deep wine red.

Where does field scabious grow best?

Field scabious belongs in full sun, meaning a spot with more than six hours of direct sunlight a day around midsummer. Moderately fertile soil is enough, ideally on the dry side and with a little lime. In the wild the species grows mainly on dykes and road verges. Since 1950 field scabious has declined by a quarter to a half, and the Dutch Red List ranks it as vulnerable.

Field scabious struggles in these spots:

• Heavy clay with standing water after a shower. The roots go deep and want soil that drains well. In wet clay they sit in water for too long.
• A lawn you mow every week. Each mowing takes the flower stems away with the clippings. In the wild the plant grows in hay meadows, which are mown far less often.

In autumn the stems and leaves die back. All winter long, almost nothing of field scabious shows above ground.

JulyJanuaryThe same border in July and in January. This is a generated image, not a photograph.

One clump grows half a metre wide at most, so a narrow border has room for a few side by side. When you put field scabious on the plan of your own garden, the app draws the plant at a grown plant's width, not at pot size.

Planting and caring for field scabious

Nurseries sell field scabious as a young plant in a pot, labelled beemdkroon in Dutch shops. A potted plant can go in at any time of year, as long as the ground is not frozen or waterlogged. Plant it just deep enough to bury the roots. Then water it well, even if it has just rained.

Leave about 35 centimetres between plants, which comes to 7 to 9 per square metre. At first that looks like a lot of bare soil around the young plants. After a few summers the clumps touch.

Many bird species breed from March to the end of July, and some keep going into August. Cutting only after flowering keeps you clear of those months.

What goes wrong with field scabious?

The plant hardly flowers. Look at the light first, because field scabious wants a sunny spot. For a new plant, choose a place with more sun.

The stems lean or flop over. That is normal for field scabious: its stems are floppy by nature. Nothing is wrong with the plant.

The young plant droops in its first summer. Give it water. Perennials need that in their first year, even a species that copes well with drought later on.

Small green or black insects sit on the stems. Those are aphids, and field scabious sometimes gets them. A few aphids belong in a healthy garden. If a colony grows large, squash it between finger and thumb.

Which insects and birds use field scabious?

A study in England recorded more than 35 species of possible pollinators on field scabious. Among them were eight species of bee, eleven of butterfly and eight of fly.

One wild bee depends on the plant almost entirely: the large scabious mining bee (Andrena hattorfiana), knautiabij in Dutch. This mining bee is listed as endangered on the Dutch Red List. In the South Limburg hills it was found at dozens of sites. The marbled white (Melanargia galathea), a very rare butterfly in the Netherlands, is often seen on purple flower heads such as those of field scabious.

Which birds eat the seeds of field scabious is not well described.

Is field scabious poisonous or edible?

Field scabious is not known to be a poisonous plant. No use as food has been described either. Not being poisonous does not make the plant edible. Touching field scabious is fine: the stems are hairy, but carry no thorns or prickles.