Alpine and Rock Garden team blog

Snowdrops are already flowering on the Rock Garden and one of the first to appear is a clump of Galanthus elwesii planted under an old Japanese maple. This species of snowdrop comes from south-east Europe, Turkey and the Caucasus and was named after the plant collector and traveller Henry Elwes in 1875. It is a strong plant, taller than the common snowdrop, Galanthus nivalis, and can have one or two green marks on the inner petals.

Galanthus elwesii on Kew's Rock Garden in early January

The marks on the inner petals vary in size and shape and sometimes they join together to make a fish-like shape.

Flower of Galanthus elwesii

Another form of Galanthus elwesii that is also on the Rock Garden is called 'Three Leaves'. Most snowdrops have two leaves, with the flower stem emerging from between them but as you can see in the next photo, Galanthus elwesii 'Three Leaves' has an extra leaf. This plant is also flowering now at Kew Gardens. There are 14 different species and subspecies of snowdrop growing on the Rock Garden and several cultivars, so over the next couple of months there should be plenty to see.

Galanthus elwesii 'Three Leaves' 

Cultivation tips

Most snowdrops like plenty of sunshine, especially in the winter when days are so short, but in the summer they do not like to be too hot and dry, even though they are dormant, so plant them somewhere that has a little dappled shade once the leaves are on the trees or is shaded from the sun for part of the day, and avoid soil that becomes dry and dusty. You can plant the bulbs in the summer, but if they have been sitting on the garden centre shelves for a long time, they can dry out too much and not come up next winter. Buy them as soon as they appear in the shops and plant straight away. Alternatively buy them growing in pots at a spring flower show. This is the best way to find the more unusual forms.

A range of different snowdrops on display at the RHS February flower show in London.

Moving snowdrops 'in the green' means when they are still in growth, after flowering, so you can be sure they haven't dried out too much. However, digging them up before going dormant can damage the roots so it is best to keep them in some soil when moving them. If you are successful you can have a wonderful display once they become established in your garden.

- Richard -

In the Woodland Garden at Kew, the colourful carpet of fallen leaves is punctuated by tall burnished stems topped with golden seedheads. These are a reminder of the glorious June display of the giant Himayalan lily (Cardiocrinum giganteum).

Cardiocrinum giganteum seedheads in the Woodland Garden

 This mighty plant comes from the Himalaya, growing in woodland clearings at altitudes of between 1,500 and 3,600 metres. The plants grow up to four metres tall and carry as many as 20 large, white, sweetly fragrant flowers on the single stem that emerges from each bulb.

The dramatic floral display of Cardiocrinum giganteum

The bulb takes about seven years to reach flowering size from seed, by which time it has a diameter of at least 20 centimetres and has pushed itself half way out of the soil. This levitation means that it is quite shallowly rooted, and it is not uncommon to find a flowering stem that has keeled over due to the weight of its waxy flowers.

l: The shallow roots and, top left, a glimpse of one of the offsets, produced around the base of the flowering stem

m: The offsets can be gently separated from the stem and replanted

r: Woodland Garden Volunteer, Kate, plants one of the offsets
 

Cardiocrinum giganteum is monocarpic, dying after flowering. However, it produces a number of new offsets which can be separated and replanted just below the soil surface. These take three to five years to flower, but never reach the stature of plants grown from seed.

The seedheads have three chambers, tightly stacked with flat triangular seeds each surrounded by a papery wing. We sow seed every year, to try to ensure a steady succession of flowering-size bulbs – the seed requires double stratification, which means it germinates after two winters in our outdoor seedframe. Seedlings are pricked out, four to a 5 cm pot and left to bulk up before being potted on as small bulbs and planted out when their bulbs reach around 2.5 cm in diameter.

The papery seeds are packed tightly into the large seedpods

 The plant prefers a rich, moist, well-drained soil and is adapted to cool, damp Himalayan summers, so in the UK it is best grown in the dappled shade of a woodland garden. We also grow a variety from Yunnan, Cardiocrinum giganteum var yunnanse, which tends to have redder and shorter stems, and a brighter red in its blooms.
 

Cardiocrinum giganteum var. yunnanense

These dramatic structures are robust and longlasting: one of Kew's diploma students used the previous year's seed heads as decorative stakes on his vegetable plot - and an enterprising spider was quick to spot a hunting opportunity too!

Cardiocrinum seed pod with spider's web

- Katie -

Scilla madeirensis is a fantastic species from, as you may have guessed from its name, the Atlantic island of Madeira. It is related to the tiny blue-flowered squills often seen in gardens but this plant is much bigger and flowers in the middle of winter. The violet-blue flowers are held in dense racemes that emerge from between bright green, pointed leaves.

The flowers of Scilla madeirensis

Only a few weeks ago the huge, purple bulbs of this plant were dormant. The leaves of this species last throughout the winter but by the summer they have died back and the plant is dormant during the long, dry summers in its natural home, where it lives on vertical rock faces. Early in October the bulbs are given fresh soil but unlike most bulbs, the roots do not die back completely so the hefty rootball has to be carefully cleaned up before new soil can be filtered in around the edges of its new pot.

Repotting the bulbs of Scilla madeirensis in early October

Kew first received this plant in 1976 when it was just one large bulb. Over the years it has multiplied but the bulbs are still attached to a thick basal plate just below the soil surface. The only way to split them is by cutting through this base. We now have several large pots of this plant in the Alpine Nursery. The bulbs are kept above the soil level to reduce the risk of them rotting.

Bulbs of Scilla madeirensis ready for their first watering

Once they have received some water, growth is remarkably quick. Only four days later the leaves had begun to shoot from the tops of the bulbs.

New growth just a few days after repotting

By the middle of November the flower spikes have developed and the first blooms are opening. It is then that the pots are moved into the Davies Alpine House and put on display. This is not a hardy plant and the pots are kept in a frost-free glasshouse in the nursery. It may be far from a true alpine but it does well in the Alpine House and at a time of year when any flowers are welcome, it makes an impressive sight.

Scilla madeirensis on display in the Davies Alpine House

- Richard -

While on a visit to Munich this autumn I had an opportunity to join Jenny on a visit to the alpine garden run by Munich Botanic Garden, located high in the Bavarian Alps. This was a follow up to a trip I made to the Alpengarten in the summer of 2008 and gave me the chance to compare the flora at different times of year.

We drove south from Munich under low cloud but as we climbed the steep, winding track up the mountains, we rose above the gloom into the glorious weather on Mt Schachen.

The view from Mt Schachen

We caught some wonderful glimpses of the Koenigshaus, just above the alpine garden, which lies 2,000 metres above sea level, in the Bavarian Alps.

Koenigshaus in the Bavarian Alps

Jenny was here to collect seed from plants growing in the alpine garden so that she can offer them to other botanic gardens through Munich's annual index seminum (seed list). The altitude and aspect of the garden means that Jenny and her colleagues have great success with many plants that we at Kew find difficult in our relatively hot, dry corner of south-east England. However, several species I have grown from Schachen seed are now thriving in the Davies Alpine House, especially in the tufa mounds - a crumbly, open-textured rock that is ideal for growing a range of small alpine plants, such as those we saw on this mountain.

Jenny Wainwright Klein collecting seeds in the Alpengarten

This was probably Jenny's last visit to the garden before it is engulfed by the first heavy snow of winter, which was forecast to arrive in a couple of days. She collected, amongst others, seed from Himalayan Primula and Meconopsis species, and we both spent time trying to photograph Cremanthodium ellisii, which was flowering its socks off!

Cremanthodium ellisii

I worked at the Schachen garden in July 2008, just a few weeks after the snow had melted and when spring had truly sprung. It is fascinating now to see how the vegetation develops over the short, intense growing season high on the mountain, how the unbelievably rich spring flower meadows were now grazed and straw-coloured, and how the tall herbs had changed the shape and character of the garden as they shot skywards. Seeing the cultivation of these plants by our Munich colleagues gives us extremely useful pointers to their treatment at Kew. And, of course, stepping out of the garden onto the mountainside, I can see the Bavarian flora in its native habitat, and again, this informs the way I will try to grow all these fantastic plants in the Davies Alpine House at Kew.

- Katie -

So, as Richard said in his introduction, the Alpine Nursery is tucked away behind the scenes at the north end of the Gardens at Kew. It’s located in an area called the Melon Yard where, surprise surprise, they used to grow melons. Now it’s rather different and houses three separate nursery areas; one supporting the work of the Jodrell Laboratory, another growing all the bedding and decorative plants that brighten areas such as the Palm House Parterre, the Duke's Garden and the Queen's Garden and then our nursery.

A view of the Alpine Nursery

The Alpine Nursery has three different types of structure. There’s a large glasshouse split into five separate zones which is heated just enough to keep the frost away in the depths of winter. Next, there’s a group of polythene tunnels covering plunge beds filled with sand and finally a couple of structures which are a little unusual. Imagine two large glasshouses with the sides and ends removed to leave just the roofs, underneath which are raised beds and mobile benches.

Plants protected from winter rain

We also have a separate area, the Alpine Yard, hidden behind the School of Horticulture with traditional brick frames and old-fashioned glasshouses (no computer-control here). Here we grow some shade-loving plants, but the real star of the show is the bonsai collection. This is diligently tended by our specialist, Richard Kernick, who looks after many attractive and aged trees which are displayed in rotation in the Bonsai House.

Hidden behind the School of Horticulture is the Alpine Yard 

Back in the Melon Yard, Jeremy Broome oversees the bulbous collections and has special responsibility for a very nice group of Mediterranean plants. Sue Skinner looks after a variety of bulbs and alpines including large groups of campanulas, saxifragas, roscoeas and sempervivums. Kit Strange mainly tends bulbous plants along with some moist shade lovers. She has a large collection of alpines at home and also gives lectures to local Alpine Garden Society (AGS) groups and organises an AGS show every year north of London. Alina Syed is responsible for propagating material for the Rock Garden and likes to experiment with different techniques. And then there's me, Graham Walters. I oversee the whole nursery and have a special responsibility for growing cushion plants such as dionysias and androsaces.

Alpine nursery staff.

Back row: Graham Walters, Richard Wilford, Jeremy Broome

Middle row: Kit Strange, Alina Syed, Sue Skinner

Front row: Richard Kernick

Next time I’ll tell you more about the different parts of the nursery and our day to day activities. See you then.

- Graham -