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Pasque Flower Gems for the Alpine Garden

May 7, 2020
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The pasque flower is one of the most glorious flowers of spring.

To most there is only one pasque flower – Pulsatilla vulgaris (aka Anemone pulsatilla). This is an easy plant to grow in any reasonable soil in a sunny position. You can also grow it in a container.

Pulsatilla vulgaris comes in a kaleidoscope of colours ranging from purples to reds to pinks to pure white. There’s also a range of equally colourful, frilly-petalled forms which some love, others loathe.

But as well as our native pasque flower, the genus Pulsatilla contains some thirty-five additional species.

Most are quite distinct and easy to identify. Others are not because this is a group of plants in which variation is usual. Neighbouring species commonly cross-pollinate and produce hybrid offspring.

While some species are easy to grow, like our native flower, others are more difficult. And some, in my experience, are nigh on impossible!

Characteristics of the Pasque Flower

Pasque flowers occur across the Northern Hemisphere in temperate regions, from the lowlands to the highest mountains. They’re particularly telling as a spectacle where they grow at the edge of melting snow.

Their fine, large, glowing flowers, borne above delightfully silky-hairy foliage, take the breath away.

Lacking significant scent seems irrelevant in the presence of such opulent beauty. Neither the insects that pollinate them, nor us, are likely to overlook them.

In fruit, many species are equally beautiful. Their tousled heads of silky seeds catch the sunlight, providing opportunities for stunning photographs.

Sourcing Rare Pasque Flowers

Some pasque flower species are hard to find. This is often because they’re rare both in the wild and in cultivation, and therefore unknown to most growers.

Rarity in cultivation is mainly because you can only propagate pasque flowers easily from seed. And this seed, like the seed of other members of the buttercup family (Ranunculaceae), is only viable for a short time after being shed. So it needs to be sown fresh.

If you want to collect seed from your plants, be aware that when fully ripe it will be blown away by the slightest breeze. So try not to leave it too long. When you can remove it with a slight tug it is ripe enough to germinate. Fresh seed will often germinate freely in a few weeks. Stored seed is less reliable.

Sowing Pasque Flower Seeds

When you sow the seeds, it’s important not to bury them too deeply. I sow it on the surface of a free draining, soil-based compost. I use 2 parts loam-based compost to 1 part sharp grit. Then cover it with a thin layer of sharp grit.

Because they’re wind-dispersed in nature, seeds have a feathery attachement – a bit like the seeds of a dandelion. In my experience, you don’t need to remove this before sowing.

Growing On Pasque Flower Seedlings

Once large enough, pirck out seedlings and plant individually in pots in gritty, soil-based compost. I use 2 parts compost to 1 part 5mm sharp grit. Water well and place in a sunny but sheltered spot until they start to grow away.

Don’t let plants become potbound. Move them on into larger pots of the same compost until they’re ready to be planted out in the garden.

If growing to maturity in pots and space is limited, you can feed them instead of repotting. Use a standard fertiliser at half the strength recommended for border plants or vegetables.

Mature plants can live for many years. They need only an occasional feed and removal of last year’s dead growth each winter. It’s best not to try to move them. Major fleshy roots are usually broken, and at best the plant will only recover slowly.

Vegetative Propagation

You can’t really ‘split’ pasque flowers. However, sometimes you can detach pieces with sufficient roots from the outside of a clump. To get them established requires intensive care in pots.

The best way to propagate a particularly fine form is by root cuttings. But this is a very chancy procedure, and is not advised for those of a nervous disposition!

Soon after flowering in spring is the best time. It’s best to use potted plants rather than open ground specimens.

Turn the plant out of its pot. Remove some sections of thick, fleshy roots with a sharp knife. Note which is the distal end (think ‘distant’ – the end furthest from the plant’s centre) and which the proximal end (think ‘proximate’ – the end closest to the plant’s centre) of each section. This will help you to plant root cuttings the right way up.

With a large root section you can sometimes make several cuttings, each at least 50mm long.

Put the root cuttings with their proximal ends uppermost, just below the surface, in a pot of very well drained propagating mixture. I use equal parts of fine grade composted forest bark, 5mm grit, and Perlite.

Top the pots off with a thin covering of the grit. Water thoroughly and place in a shaded cold frame or unheated glasshouse. Make sure that they never dry out but are never waterlogged either. Wait until strong new growth emerges from the cut surface. Then pot the cuttings up as above for seedlings.

For plants in the open ground, excavate gently around the root system until you find suitable roots. Only remove as much as you think the plant is unlikely to miss.

The Common Pasque Flower – Pulsatilla vulgaris

The name ‘pasque flower’ is used throughout Europe. It comes from the fact that Pulsatilla vulgaris generally blooms around Easter-time (Paschal, Pascale). It grows widely in mainland Europe. In the UK it is the only native species pasque flower and quite rare. It’s restricted to a few undisturbed chalk grassland sites in Southern England.

You can buy Pulsatilla vulgaris in a variety of colours and flower forms. Look for them in good garden centres or specialist nurseries in spring. Or you can raise them from seed as described above – the AGS Seed Exchange is a great source and open to all Alpine Garden Society members.

Seedlings from any particular seedlot will likely be a mixed bunch. Size and vigour, leaf division and hairiness, as well as flower colour, are all likely to vary. Various shades of pink, red and purple are likely, so if you are choosy it is best to buy plants in flower.

The reason for this variability is that our native pasque flower has been in cultivation for centuries, allowing many forms and variants to be selected. Also, P. vulgaris. crosses readily with closely related species commonly grown in gardens, notably P. grandis and P. halleri.

Placement in the Garden

Pulsatilla vulgaris and its hybrids are very versatile plants. They look equally ‘right’ in the mixed flower border, among bulbs in informal settings, or in the alpine garden.

Self-sown seedlings quite often pop up around the garden. If they’re in acceptable places it’s best to leave them to grow on. They’ll often produce beautiful displays. If not, they may be carefully lifted and grown on in pots for planting out later.

They also make welcome gifts for fellow gardeners!

Pulsatilla halleri subsp. slavica

Pulsatiulla halleri, in all its very variable forms, is among the most beautiful of an outstanding genus. I’ve grown several of this pasque flower under differing names over the years, some perhaps dubiously distinct from others.

Indeed, some may have been hybrids with the common pasque flower, or with P. grandis, but what does that matter if they are special? All have been easy, long-lived plants, flowering before any others in my garden, usually at their best in mid-March.

The best came to me as seed from a Czech correspondent, Jaroslav Kazbal, in the early 1990s. He’d collected it in the wild in the Western Carpathians, labelling the seed packet Pulsatilla slavica. This is generally now included in P. halleri, as subspecies slavica.

I raised seedlings and planted them around the garden. When they flowered they were variable, some hairier than others. All bore sumptuous flowers, in various shades of pinkish-mauve, bluish-mauve, or lavender-blue.

 

One spring I noticed that one of the plants, growing in a raised bed, had self-seeded into the gravel path below. I decided to leave the seedlings where they were, thinking little more about them until they started to flower.

One of them (above right) was the best I have ever raised. This in spite of growing in a path so hard that a pick would have been needed to plant it there!

It lived for many years and produced much seed, some of which made its way to the AGS seed exchange.

Pulsatilla grandis ‘Budapest Blue’

Some plants are the stuff of which legends are made. One such is Pulsatilla ‘Budapest’.

Its history has been told (with various degrees of inaccuracy!) many times. The true story was outlined by Mike Stone in The Rock Garden, The Journal of the Scottish Rock Garden Club (Vol. 24, No. 2: pp. 155-158, 1995).

Here’s a brief summary: In volume 12 of the New Flora and Sylva (1940), Mrs Dorothy Gorton describes (under the name Anemone pulsatilla ‘Budapest var.’) how, in the spring of 1920 she witnessed bunches of pasque flowers for sale in a Budapest market. Inquiries revealed that they had originated in the Svag Hegy, a hill to the west of the city.

Mrs Gorton obtained seed that autumn which germinated successfully. A half-tone plate of one of these plants in Mrs Gorton’s garden accompanied the article. In the same publication the editor described the colour of these plants as “pale mauve, occasionally pale blue”.

Plants derived from this source were cultivated in various British and Irish gardens for many years after WW2. None seems to have had flowers of the stunning pale blue to mauve that we associate with this plant today.

Pulsatilla ‘Budapest’ FCC

Fast forward to 1963 when the famous gardener, Valerie Finnis, exhibited a “stunning plant” under the name Pulsatilla ‘Budapest’. The RHS committee immediately awarded it a First Class Certificate, the highest accolade the RHS can bestow on any plant. Unfortunately the plant had been dug up from the garden and did not survive. Nor could it be propagated before its demise.

It subsequently emerged that this fabled plant had come from a different source. Valerie Finnis had obtained seed from Munich Botanic Garden. So the ‘true’ ‘Budapest’, at least as far as the FCC is concerned, died with Valerie Finnis’ plant. All plants subsequently grown and shown as ‘Budapest’ are wrongly named.

Pulsatilla ‘Budapest Blue’

However, the story does not end there. In recent years a seed strain of carefully selected plants showing most if not perhaps all the characteristics of ‘Budapest’ has emerged. These look-alike plants are now by general agreement grown under the name Pulsatilla grandis ‘Budapest Blue’.

My good (late) friends, Ron and Joan Beeston, known to many Society members, gave me the plant illustrated here. It has been growing in the same position on top of a sunny raised bed for 10 years. It receives no special treatment and flowers freely in late March, wowing all who see it.

All plants labelled ‘Budapest Blue’ are likely to be exquisite, but they’re quite variable. Some bear flowers of a purer blue than others.

Once you have a worthy plant it’s a good plan to raise batches from your own seed. When they flower, select the best, and only then plant them out or pass them on.

Similarly, only send seed of superior specimens to the seed exchanges under the Name Pulsatilla grandis ‘Budapest Blue’, or just Pulsatilla ‘Budapest Blue’.

Pulsatilla alpina subspecies apiifolia

The long-used name Pulsatilla alpina subsp. sulphurea has been supplanted by Pulsatilla alpina subsp. apiifolia. This is a pity. The old name – related to the word ‘sulphur’ – was so descriptive of the flower colour, which is generally a clear pale to mid yellow.

This yellow form of Pulsatilla alpina is generally, but by no means exclusively found on acid soils. Pulsatilla alpina subsp. alpina, which is invariably white, on neutral to alkaline substrata.

This might in part explain why subsp. apiifolia is easier to grow in the acid soil of my garden. Indeed, I have never really succeeded with subsp. alpina.

Both the white and yellow subspecies are quite robust plants, reaching about 40 cm tall in flower. Therefore, it is best to place them towards the back of a rock garden bed or border.

Pulsatilla scherfelii 

This pasque flower has long been known by the appropriate name Pulsatilla alba (‘alba’ being Latin for white). However, recent studies have concluded that it should revert to an earlier, much less descriptive name, Pulsatilla scherfelii.

It is uncommon in cultivation, probably because it may seem a less desirable garden plant than Pulsatilla alpina, to which it is closely related. Seed is rarely collected in the wild, because populations tend to be confused with P. alpina. The confusion is easily understood, as both species occupy similar alpine meadow and other grassy habitats.

In the garden it is much easier to tell Pulsatilla scherfelii and Pulsatilla alpina apart. P. scherfelii is smaller, slower growing, and perhaps more elegant.

In my experience, P. scherfelii is not among the easier pasque flowers to cultivate. The plant pictured below is growing in a slightly raised, moraine bed. This comprises freely drained, shaly surface material, overlying a heavier soil. Water trickles constantly through clay pipes 30cm below the surface, ensuring the soil never dries out.

Pulsatilla zimmermannii?

The name of this attractive, small pasque flower is certainly in doubt, as acknowledged by Grey-Wilson in his book Pasque-flowers: The Genus Pulsatilla.

I raised my plants from seed collected in the wild in Hungary. It has a limited distribution there and in neighbouring Slovakia. My plants have similar foliage and floral bracts to some forms of Pulsatilla pratensis. This tallies with the tentative assignment of Pulsatilla zimmermanii to that species grouping.

But the wide-open, horizontal to upward-facing flowers, are unlike the nodding, more bell-shaped blooms of Pulsatilla pratensis. Anyway, it is a very pretty little pasque flower, well worthy of cultivation.

Pulsatilla albana and its allies

This group comprises pasque flower species with natural distributions predominantly in Central Asia. I have grown several of them more or less successfully, but haven’t been able to obtain others.

The relationships between members of the group haven’t really been sorted out. This is largely because many taxa overlap markedly in their distributions, confusing attempts to separate them. But it seems probable that some of these ‘species’ are no more than forms, mostly differing in minor characteristics.

Pulsatilla albana is a pretty little plant with predominantly pale yellow. flowers. They are sometimes, as in my plant illustrated here, flushed with violet on the reverse of the sepals. It has been easy and long-lived in a part-sunny, raised bed in quite heavy soil.

Pulsatilla ambigua

This pasque flower is one of my favourites. It may be less imposing than species of the Western European group (P. vulgaris, P. grandis and P. halleri). But it is no less beautiful to my eyes.

I have two forms, both kindly given to me by Peter Erskine, a pale pink and a pure white. I love them both equally. It is not difficult to grow in any sunny position in well drained, but reasonably fertile soil.

Pulsatilla ambigua sets plenty of seed, but limited evidence suggests that it may hybridise with other species growing nearby. So, if we are to retain the species in cultivation, it is sensible to grow seed parents away from other pulsatillas. This may be easier with plants grown in pots than in the open garden.

The home of Pulsatilla ambigua is the high mountains, steppes and woodland margins of Western Siberia, eastwards to China and Mongolia.

Pulsatilla georgica or P. sukaczewii?

I have in the garden a pretty little pasque flower which I obtained from a friend under the name Pulsatilla georgica. This name covers one of the species in the Central Asian group which is of uncertain taxonomic status. Some authorities reduce it to subspecific status as P. albana subsp. georgica, others preferring to accord it full specific status.

Also, it appears that most seed under the name Pulsatilla georgica in cultivation is either Pulsatilla violacea (clearly not in this case – P. violacea flowers are violet!) or P. sukaczewii. The latter is an eastern Asian species only distantly related to P. georgica. 

Looking at the photographs of P. georgica and P. sukaczewii in Grey-Wilson’s book, it seems likely that my plant is the latter.

Whatever its origins this is a lovely little pasque flower, with parsley-like leaves and abundant, nodding to erect white flowers. Sometimes they are flushed outside, to varying degrees, with blue-grey or pink.

Pulsatilla vernalis – the Spring Pasque Flower, or ‘Lady of the Snows’

This is the epitome of a high alpine plant, occurring frequently at elevations above 3000m. It’s commonly called ‘The Lady of the Snows’. It’s glistening, creamy-white blossoms, often found at the edge of melting snow banks, are a glorious sight, not easily forgotten.

The backs of the sepals are generally darker coloured, varying from pink, through violet to dark greyish-blue. They, and the short flower stalks and bracts, are densely covered in soft hairs, which may be cream, bluish or russet brown.

This velvety opulence adds greatly to the appeal of the whole plant. The equivalent Western North American pasque flower is the almost equally stunning Pulsatilla occidentalis. I’ve seen masses of this in full flower on Mt Rainier, and although that was more than 30 years ago, I remember it vividly.

Cultivating the Spring Pasque Flower

I’ve tried repeatedly to cultivate both these species outside in North Wales.

Pulsatilla occidentalis has proven impossible for me. Seed germinates sparingly and I’ve never got a plant beyond small rosette stage.

I’ve had marginally more success with Pulsatilla vernalis, but only with the compact Norwegian form. And only when the small flowering-sized plants have been covered with glass in winter. The picture shows an old glass pickle jar used for this purpose!

I’m sure it’s chief value is to protect the nascent flower buds, nestling down in the rosette, from our high rainfall. In the wild these would be covered with a blanket of protective snow throughout the dormant period.

I know I’m not alone in finding Pulsatilla vernalis difficult to keep alive outside, let alone to flower it freely. All the big old plants I’ve seen have been in pots on the showbench, and a splendid sight they make. But somehow, for me, they are no substitute for a plant grown hard in the garden that looks in character.

If you live in a wet climate like ours I strongly advise you to give it a try with some seedlings. Plant them out in a sunny spot in very well drained, but fertile soil, and cover them in winter.

When you see those furry flowers buds beginning to develop you’ll know that you’ve succeeded in taming one of the great alpine beauties.

Pasque Flowers: The Genus Pulsatilla

For a full, beautifully illustrated account of pasque flowers in the wild and in cultivation, I advise you to consult the standard work on the subject. Written by one of our most eminent and knowledgeable members, Dr Christopher Grey-Wilson it is entitled Pasque-Flowers: the Genus Pulsatilla. It was published privately by the author, Kenninghall, Norfolk, UK 2014.

This work includes a careful analysis regarding whether Pulsatilla should be retained as a separate genus or included within Anemone. Dr Grey-Wilson’s conclusion is that for all practical (including horticultural) purposes the genus Pulsatilla should be retained. This is the position adopted in this article. A revised edition of this seminal work is due to be published soon by the AGS.

Image of John Good John Good