Cowslip: flowering time, location & toxicity

Franziska
Franziska
Franziska
Franziska

I study organic agriculture and am very connected to plants and nature. At home, we run a small organic farm with a few animals, various crops and some forest. The production of healthy food in harmony with nature inspires me anew time and again.

Favourite fruit: apple, pear and plum
Favourite vegetables: potato, pumpkin and spinach

The “oxslip”, the radiant, yellow-flowered cowslip, awakens from hibernation in spring. It is as a unique medicinal plant and an important food source for insects.

Primula veris plants
Cowslips are low-maintenance and valuable bedding plants [Photo: MNStudio/ Shutterstock.com]

The cowslip is known by many names: common cowslip, oxslip, primrose and primula are other names of this plant, of which the botanic name is Primula veris. It brings with it many useful characteristics from which biodiversity also benefits greatly.

Cowslip: flowering time, characteristics and origin

Botanically, the Primula veris belongs to the primrose family (Primulaceae). Cowslip is only one among quite a few Primula species. A distinctive feature of Primula veris is probably the intense fragrance of its flowers, which not only smells pleasant to us but also attracts insects.

This lime-loving Primula veris occurs throughout Europe and the Near East but not in the southern Mediterranean countries and the extreme north. It prefers sunny to semi-shady meadows, semi-arid grasslands, dry meadows and sparse deciduous forests as well as, for example, oak forests or hornbeam forests and forest edges. In the mountains of Austria, they are sometimes even found at altitudes of up to 2,000 metres. As for soil requirements, a calcareous, low-nitrogen, humusy, loose and loamy soil is suitable for cowslip.

Cowslip grows as a perennial, herbaceous plant that reaches a growth height of 10 to 20 cm and overwinters with a short and thickened rhizome. It has a short, strong taproot with which it holds well in the soil. Many small lateral roots form around this taproot. From the base of the plant is constantly developing new rosettes of leaves. After some time, loose, fragrant groups of plants are formed. Leaf shape is ovate to oblong with coarsely toothed leaf margins. The upper side of their leaves has a dark green wrinkled structure covered with plant hairs. The underside of the leaf is also hairy and light green. The leaf margin is curled downward in young leaves. The flower stalks are slightly hairy and without leaves.

Flowering cowslip
Cowslip can be found by the wayside early in the spring [Photo: weha/ Shutterstock.com]

The arrangement of golden yellow flowers resembles a bunch of keys, which explains the name of the flower in Germany (Schlüsselblume). The flowering time of the cowslip is from March to May. Up to 20 individual flowers form a flower umbel. The single flower consists of 5 deep yellow petals. An unusual characteristic of Primula veris is the so-called distylie. This means that there are different types of flowers of cowslip. Some have a short pistil and a high stamen position, while other flowers have a long pistil and a low stamen. The whole purpose is to avoid self-fertilisation and promote cross-pollination by insects.

The enchanting flowers give off a pleasant fragrance that attracts pollinating insects in particular. Only pollinators with a long proboscis, such as bumblebees and butterflies, can reach the nectar through the flower tube but some pollen is also available for wild bees. As an early bloomer, cowslip is already an important food source in early spring.

A bee on cowslip blossom
Bees collect pollen from cowslips [Photo: B.Jaunberzina/ Shutterstock.com]

Is the primrose a protected species?

Primroses are protected in Germany as well as in many other countries. The fragrant herald of spring was awarded the title “Flower of the Year 2016” to promote the protection of the plant, which has become rare and underestimated. Their wild populations are in fact highly endangered in many locations in Germany and are therefore under protection. Their habitat is threatened in more and more areas by intensive use and fertilisation of meadows, pastures and farmland. In other places, the traditional use of meadows is increasingly being pushed into the background, so that bushes and trees with their heavy shading are crowding out the light-loving primroses. It is therefore classified as critically endangered in the red lists of the federal states, especially in northern Germany.
Therefore, primroses must not be dug up or collected in whole or in part.

cowslip-meadow
Cowslip is displaced from intensively used sites such as meadows [Photo: JMpx/ Shutterstock.com]

Danger of confusion

It is easy to mistake cowslip Primula veris for oxslip Primula elatior. However, the latter tends to grow in moist areas along stream banks, in wooded areas, and on river and lake shores. Unlike other primroses, cowslip has strongly fragrant flowers with orange, five-petalled spots, called nectar guides, at the base of the petals. The oxslip has a less strong fragrance and does not have orange-yellow nectar guides The calyx of the cowslip is also narrower than that of the cowslip. Another difference is the shape of the leaves: in the true cowslip, the base of the leaf is more blunt.

Cowslip
The cowslip is not as fragrant as the oxlip [Photo: Svetlana Mahovskaya/ Shutterstock.com]

Planting cowslip: Location and procedure

In the garden, primrose prefers a site in sun or partial shade in lean, humus-rich, calcareous, loamy and loose soil. To adjust the pH of the soil, our Plantura Organic Lawn & Garden Lime is suitable when soil conditions are too acidic. This harmless, finely granulated lime is easy to apply and improves crumbling in the soil. Due to the low nutrient requirements of cowslip, additional fertilisation is not necessary. The Primula veris is hardy and can withstand frosts to – 28 °C.

One suitable material for outdoor planting is our Plantura Organic All Purpose Compost. Matching the moderate nutrient requirements of the plant, it provides everything it needs to grow. In addition, the coarse structure of the soil gives it stability and prevents it from sinking together. Since primroses grow approximately 20 cm wide, a planting distance of 25 cm is recommended, which gives 15 to 17 specimens per square meter. It prefers to grow in small troops and groups of up to 20 plants and looks most impressive that way.

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Organic All Purpose Compost, 40L
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Cowslip is also very suitable for the pot. For this purpose, use a flower pot with a diameter of about 25 cm, so that the plant has enough space. Here, our Plantura Organic All Purpose Compost also provides sufficient nutrients for healthy plant growth.

Tip: A drainage layer, for example, of clay shards prevents waterlogging in the flower pot.

Without further care cowslip grows beautifully into lush clusters with many flowerheads. Primroses are an important element for wild gardens. Beautiful pictures are created by combinations of flowering ornamental and useful shrubs and areas richly stocked with Primula veris.

Cowslip in the snow
The hardy Primula veris heralds the arrival of spring [Photo: Karen Faljyan/ Shutterstock.com]

Caring for primula veris

Especially in the wild, the beautiful perennial cowslip has become rare but in the garden, it gives a lot of pleasure because it requires little care. Except in the warm summer months, oxslips do not need additional watering. In hot and dry periods should be watered regularly to prevent drying of the root ball. Fertilisation is not necessary for wild perennials, and nutrient additions from occasional repotting are sufficient for potted plants as well.

Flowering Primula veris
The cowslip already delights with its flowers in early summer [Photo: weha/ Shutterstock.com]

Below are some species and varieties that are particularly well suited to the early summer garden:

  • Primula veris ssp. columnae: This form of cowslip is characterised by a dense trimming of white hairs on the underside of the leaves and a lemon yellow flower.
  • Primula veris ssp. macrocalyx: The subspecies is native to Asia and has very large, yellow to orange flowers.
Primula veris ssp. macrocalyx
Primula veris ssp. macrocalyx has particularly large, yellow flowers [Photo: Edita Medeina/ Shutterstock.com]
  • Primula veris ‘Sunset Shades’:The flowers of this variety appear in sunset colours, which range from yellow to ochre and orange to red, creating varied accents in the garden.
Primula veris 'Sunset Shades'
The flowers of Primula veris ‘Sunset Shades’ have a special luminosity [Photo: Bad Birch/ Shutterstock.com]
  • Primula veris ‘Red Shades’: It is a red-flowered form of cowslip that is very suitable to complement the yellow-flowered wild type. The requirements of these plants are similar to those of the original Primula veris.
Red cowslip
The red form of the primrose provides plenty of variety in the garden [Photo: Nadya N/ Shutterstock.com]

Propagating cowslip

It is very easy to propagate cowslip by seed: Primrose reliably self-seed. You can also sow them with self-collected or purchased seeds but should follow some tips: Due to the distylie described above, seeds are set only when short-handled and long-handled specimens. In addition, even collected cowslip seeds usually do not last long and quickly lose their ability to germinate. For this reason, at best, they should be applied immediately after seed ripening.

Sowing from seed: procedure

Cowslip is a cold germinator. That is, the seeds need a cooling period to break down the inhibition of germination. For this purpose, the seeds can be stored in the refrigerator for 3 to 4 weeks. It is much easier to sow the seeds outdoors in autumn and let the natural weather take care of breaking down the germination inhibition. The seeds are covered only very thinly with soil and always kept slightly moist. The optimum germination temperature is 10 to 15 °C.

Tip: Primula plants tend to bastardise and quickly mix with other Primula species. The result can be exciting and decorative but also look pretty weird. Therefore, if not hybrids but “pure” cowslip varieties are to be propagated, it is necessary to selectively isolate the plants, as they are pollinated by insects.

Due to its taproot division is not recommended. However, sometimes side rosettes are formed, which can be removed and transplanted in the spring.

Primrose flowers
The primrose family offers a great variety [Photo: Dajra/ Shutterstock.com]

Is the cowslip poisonous?

Primroses are not poisonous. They belong to the primrose family but should not be confused with primroses. In fact, many primrose species produce primin, which can because skin irritation but cowslip does not fall into this category.

Use and medicinal characteristics of cowslip

It is not only an important herb for many animals but also has a high value in medicine. Due to the promising healing characteristics of cowslip, it has been one of the ancient medicinal and medicinal plants for many centuries. Thus, there are several areas of use for this unique wild perennial. The plant contains saponins, especially in the root and flowers, which are used for their diuretic, anti-inflammatory and expectorant effect of cowslip in respiratory diseases or colds. It is used internally as cowslip tea or syrup, alternatively externally as a tincture.

Tip: Saponins can irritate the stomach, which can because stomach upset in sensitive individuals when cowslip is used internally.

In addition, the cowslip has edible components such as the young leaves and flowers, which can be collected between March and June. They can be used in many ways, such as raw for salads, as ingredients in soups or as decoration for desserts. The cowslip flowers also flavor herbal teas, as they have a slightly sweet taste. Please note that the cowslip is protected and therefore may not be collected.

Cowslip tea
Cowslip tea apparently relieves the symptoms of respiratory diseases [Photo: FotoHelin/ Shutterstock.com]

Cowslip is not only a species worthy of protection but also a feast for the eyes in the garden. In addition, it has many uses as a medicinal plant. Are you interested in other medicinal plants? Then read our portrait of the fenugreek – this also finds versatile use in the kitchen and the home pharmacy.

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